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treewide: Add SPDX license identifier - Makefile/Kconfig Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-19 20:07:45 +08:00
# SPDX-License-Identifier: GPL-2.0-only
kconfig: add defconfig_list/module option This makes it possible to change two options which were hardcoded sofar. 1. Any symbol can now take the role of CONFIG_MODULES 2. The more useful option is to change the list of default file names, which kconfig uses to load the base configuration if .config isn't available. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-06-09 13:12:45 +08:00
config DEFCONFIG_LIST
string
[PATCH] uml: use DEFCONFIG_LIST to avoid reading host's config This should make sure that, for UML, host's configuration files are not considered, which avoids various pains to the user. Our dependency are such that the obtained Kconfig will be valid and will lead to successful compilation - however they cannot prevent an user from disabling any boot device, and if an option is not set in the read .config (say /boot/config-XXX), with make menuconfig ARCH=um, it is not set. This always disables UBD and all console I/O channels, which leads to non-working UML kernels, so this bothers users - especially now, since it will happen on almost every machine (/boot/config-`uname -r` exists almost on every machine). It can be workarounded with make defconfig ARCH=um, but it is non-obvious and can be avoided, so please _do_ merge this patch. Given the existence of options, it could be interesting to implement (additionally) "option required" - with it, Kconfig will refuse reading a .config file (from wherever it comes) if the given option is not set. With this, one could mark with it the option characteristic of the given architecture (it was an old proposal of Roman Zippel, when I pointed out our problem): config UML option required default y However this should be further discussed: *) for x86, it must support constructs like: ==arch/i386/Kconfig== config 64BIT option required default n where Kconfig must require that CONFIG_64BIT is disabled or not present in the read .config. *) do we want to do such checks only for the starting defconfig or also for .config? Which leads to: *) I may want to port a x86_64 .config to x86 and viceversa, or even among more different archs. Should that be allowed, and in which measure (the user may force skipping the check for a .config or it is only given a warning by default)? Cc: Roman Zippel <zippel@linux-m68k.org> Cc: <kbuild-devel@lists.sourceforge.net> Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20 14:28:23 +08:00
depends on !UML
kconfig: add defconfig_list/module option This makes it possible to change two options which were hardcoded sofar. 1. Any symbol can now take the role of CONFIG_MODULES 2. The more useful option is to change the list of default file names, which kconfig uses to load the base configuration if .config isn't available. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-06-09 13:12:45 +08:00
option defconfig_list
init/Kconfig: Use short unix-style option instead of --longname Avoids warning messages with the latest release of toybox, which never bothered to implement the --longopts nothing was using. Signed-off-by: Rob Landley <rob@landley.net> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-08 12:06:43 +08:00
default "/lib/modules/$(shell,uname -r)/.config"
kconfig: add defconfig_list/module option This makes it possible to change two options which were hardcoded sofar. 1. Any symbol can now take the role of CONFIG_MODULES 2. The more useful option is to change the list of default file names, which kconfig uses to load the base configuration if .config isn't available. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-06-09 13:12:45 +08:00
default "/etc/kernel-config"
init/Kconfig: Use short unix-style option instead of --longname Avoids warning messages with the latest release of toybox, which never bothered to implement the --longopts nothing was using. Signed-off-by: Rob Landley <rob@landley.net> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-08 12:06:43 +08:00
default "/boot/config-$(shell,uname -r)"
kbuild: use KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LIST Most of the Kconfig commands (except defconfig and all*config) read the .config file as a base set of CONFIG options. When it does not exist, the files in DEFCONFIG_LIST are searched in this order and loaded if found. I do not see much sense in the last two lines in DEFCONFIG_LIST. [1] ARCH_DEFCONFIG The entry for DEFCONFIG_LIST is guarded by 'depends on !UML'. So, the ARCH_DEFCONFIG definition in arch/x86/um/Kconfig is meaningless. arch/{sh,sparc,x86}/Kconfig define ARCH_DEFCONFIG depending on 32 or 64 bit variant symbols. This is a little bit strange; ARCH_DEFCONFIG should be a fixed string because the base config file is loaded before the symbol evaluation stage. Using KBUILD_DEFCONFIG makes more sense because it is fixed before Kconfig is invoked. Fortunately, arch/{sh,sparc,x86}/Makefile define it in the same way, and it works as expected. Hence, replace ARCH_DEFCONFIG with "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)". [2] arch/$(ARCH)/defconfig This file path is no longer valid. The defconfig files are always located in the arch configs/ directories. $ find arch -name defconfig | sort arch/alpha/configs/defconfig arch/arm64/configs/defconfig arch/csky/configs/defconfig arch/nds32/configs/defconfig arch/riscv/configs/defconfig arch/s390/configs/defconfig arch/unicore32/configs/defconfig The path arch/*/configs/defconfig is already covered by "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)". So, this file path is not necessary. I moved the default KBUILD_DEFCONFIG to the top Makefile. Otherwise, the 7 architectures listed above would end up with endless loop of syncconfig. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-28 11:46:40 +08:00
default "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)"
kconfig: add defconfig_list/module option This makes it possible to change two options which were hardcoded sofar. 1. Any symbol can now take the role of CONFIG_MODULES 2. The more useful option is to change the list of default file names, which kconfig uses to load the base configuration if .config isn't available. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-06-09 13:12:45 +08:00
kbuild: ensure full rebuild when the compiler is updated Commit 21c54b774744 ("kconfig: show compiler version text in the top comment") added the environment variable, CC_VERSION_TEXT in the comment of the top Kconfig file. It can detect the compiler update, and invoke the syncconfig because all environment variables referenced in Kconfig files are recorded in include/config/auto.conf.cmd This commit makes it a CONFIG option in order to ensure the full rebuild when the compiler is updated. This works like follows: include/config/kconfig.h contains "CONFIG_CC_VERSION_TEXT" in the comment block. The top Makefile specifies "-include $(srctree)/include/linux/kconfig.h" to guarantee it is included from all kernel source files. fixdep parses every source file and all headers included from it, searching for words prefixed with "CONFIG_". Then, fixdep finds CONFIG_CC_VERSION_TEXT in include/config/kconfig.h and adds include/config/cc/version/text.h into every .*.cmd file. When the compiler is updated, syncconfig is invoked because init/Kconfig contains the reference to the environment variable CC_VERTION_TEXT. CONFIG_CC_VERSION_TEXT is updated to the new version string, and include/config/cc/version/text.h is touched. In the next rebuild, Make will rebuild every files since the timestamp of include/config/cc/version/text.h is newer than that of target. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-04-23 22:23:52 +08:00
config CC_VERSION_TEXT
string
default "$(CC_VERSION_TEXT)"
help
This is used in unclear ways:
- Re-run Kconfig when the compiler is updated
The 'default' property references the environment variable,
CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd.
When the compiler is updated, Kconfig will be invoked.
- Ensure full rebuild when the compier is updated
include/linux/kconfig.h contains this option in the comment line so
fixdep adds include/config/cc/version/text.h into the auto-generated
dependency. When the compiler is updated, syncconfig will touch it
and then every file will be rebuilt.
kconfig: add CC_IS_GCC and GCC_VERSION This will be useful to specify the required compiler version, like this: config FOO bool "Use Foo" depends on GCC_VERSION >= 40800 help This feature requires GCC 4.8 or newer. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-28 17:22:01 +08:00
config CC_IS_GCC
kbuild: use $(CC_VERSION_TEXT) to evaluate CC_IS_GCC and CC_IS_CLANG The result of '$(CC) --version | head -n 1' has already been computed by the top Makefile, and stored in the environment variable, CC_VERSION_TEXT. 'echo' is cheaper than the two commands $(CC) and 'head' although this optimization is not noticeable level. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
2020-04-23 22:23:51 +08:00
def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q gcc)
kconfig: add CC_IS_GCC and GCC_VERSION This will be useful to specify the required compiler version, like this: config FOO bool "Use Foo" depends on GCC_VERSION >= 40800 help This feature requires GCC 4.8 or newer. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-28 17:22:01 +08:00
config GCC_VERSION
int
kbuild: clean up scripts/gcc-version.sh Now that the Kconfig is the only user of this script, we can drop unneeded code. Remove the -p option, and stop prepending the output with zero, so that Kconfig can directly use the output from this script. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-03-01 15:10:22 +08:00
default $(shell,$(srctree)/scripts/gcc-version.sh $(CC)) if CC_IS_GCC
kconfig: add CC_IS_GCC and GCC_VERSION This will be useful to specify the required compiler version, like this: config FOO bool "Use Foo" depends on GCC_VERSION >= 40800 help This feature requires GCC 4.8 or newer. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-28 17:22:01 +08:00
default 0
init/kconfig: Add LD_VERSION Kconfig This option can be used in Kconfig files to compare the ld version and enable/disable incompatible config options if required. This option is used in the subsequent patch along with GCC_VERSION to filter out an incompatible feature. Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-30 19:41:38 +08:00
config LD_VERSION
int
default $(shell,$(LD) --version | $(srctree)/scripts/ld-version.sh)
kconfig: add CC_IS_CLANG and CLANG_VERSION This will be useful to describe the clang version dependency. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-28 17:22:02 +08:00
config CC_IS_CLANG
kbuild: use $(CC_VERSION_TEXT) to evaluate CC_IS_GCC and CC_IS_CLANG The result of '$(CC) --version | head -n 1' has already been computed by the top Makefile, and stored in the environment variable, CC_VERSION_TEXT. 'echo' is cheaper than the two commands $(CC) and 'head' although this optimization is not noticeable level. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
2020-04-23 22:23:51 +08:00
def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q clang)
kconfig: add CC_IS_CLANG and CLANG_VERSION This will be useful to describe the clang version dependency. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-28 17:22:02 +08:00
kbuild: add CONFIG_LD_IS_LLD Similarly to the CC_IS_CLANG config, add LD_IS_LLD to avoid GNU ld specific logic such as ld-version or ld-ifversion and gain the ability to select potential features that depend on the linker at configuration time such as LTO. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Acked-by: Masahiro Yamada <masahiroy@kernel.org> [nc: Reword commit message] Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-04-29 06:14:15 +08:00
config LD_IS_LLD
def_bool $(success,$(LD) -v | head -n 1 | grep -q LLD)
kconfig: add CC_IS_CLANG and CLANG_VERSION This will be useful to describe the clang version dependency. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-28 17:22:02 +08:00
config CLANG_VERSION
int
default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
init/Kconfig: add CONFIG_CC_CAN_LINK Currently, scripts/cc-can-link.sh is run just for BPFILTER_UMH, but defining CC_CAN_LINK will be useful in other places. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-01 08:58:39 +08:00
config CC_CAN_LINK
bpfilter: match bit size of bpfilter_umh to that of the kernel bpfilter_umh is built for the default machine bit of the compiler, which may not match to the bit size of the kernel. This happens in the scenario below: You can use biarch GCC that defaults to 64-bit for building the 32-bit kernel. In this case, Kbuild passes -m32 to teach the compiler to produce 32-bit kernel space objects. However, it is missing when building bpfilter_umh. It is built as a 64-bit ELF, and then embedded into the 32-bit kernel. The 32-bit kernel and 64-bit umh is a bad combination. In theory, we can have 32-bit umh running on 64-bit kernel, but we do not have a good reason to support such a usecase. The best is to match the bit size between them. Pass -m32 or -m64 to the umh build command if it is found in $(KBUILD_CFLAGS). Evaluate CC_CAN_LINK against the kernel bit-size. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-04-29 11:45:13 +08:00
bool
default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(m64-flag)) if 64BIT
default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(m32-flag))
bpfilter: check if $(CC) can link static libc in Kconfig On Fedora, linking static glibc requires the glibc-static RPM package, which is not part of the glibc-devel package. CONFIG_CC_CAN_LINK does not check the capability of static linking, so you can enable CONFIG_BPFILTER_UMH, then fail to build: HOSTLD net/bpfilter/bpfilter_umh /usr/bin/ld: cannot find -lc collect2: error: ld returned 1 exit status Add CONFIG_CC_CAN_LINK_STATIC, and make CONFIG_BPFILTER_UMH depend on it. Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Alexei Starovoitov <ast@kernel.org>
2020-05-09 15:39:15 +08:00
config CC_CAN_LINK_STATIC
bool
default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) -static $(m64-flag)) if 64BIT
default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) -static $(m32-flag))
init/Kconfig: add CONFIG_CC_CAN_LINK Currently, scripts/cc-can-link.sh is run just for BPFILTER_UMH, but defining CC_CAN_LINK will be useful in other places. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-01 08:58:39 +08:00
jump_label: move 'asm goto' support test to Kconfig Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
2018-12-30 23:14:15 +08:00
config CC_HAS_ASM_GOTO
def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
Kconfig: add config option for asm goto w/ outputs This allows C code to make use of compilers with support for output variables along the fallthrough path via preprocessor define: CONFIG_CC_HAS_ASM_GOTO_OUTPUT [ This is not used anywhere yet, and currently released compilers don't support this yet, but it's coming, and I have some local experimental patches to take advantage of it when it does - Linus ] Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-15 06:18:11 +08:00
config CC_HAS_ASM_GOTO_OUTPUT
depends on CC_HAS_ASM_GOTO
def_bool $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
arm64: Add support for relocating the kernel with RELR relocations RELR is a relocation packing format for relative relocations. The format is described in a generic-abi proposal: https://groups.google.com/d/topic/generic-abi/bX460iggiKg/discussion The LLD linker can be instructed to pack relocations in the RELR format by passing the flag --pack-dyn-relocs=relr. This patch adds a new config option, CONFIG_RELR. Enabling this option instructs the linker to pack vmlinux's relative relocations in the RELR format, and causes the kernel to apply the relocations at startup along with the RELA relocations. RELA relocations still need to be applied because the linker will emit RELA relative relocations if they are unrepresentable in the RELR format (i.e. address not a multiple of 2). Enabling CONFIG_RELR reduces the size of a defconfig kernel image with CONFIG_RANDOMIZE_BASE by 3.5MB/16% uncompressed, or 550KB/5% compressed (lz4). Signed-off-by: Peter Collingbourne <pcc@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-01 09:18:42 +08:00
config TOOLS_SUPPORT_RELR
Revert "init/Kconfig: Fix infinite Kconfig recursion on PPC" This reverts commit 71c67a31f09fa8fdd1495dffd96a5f0d4cef2ede. Commit 117acf5c29dd ("powerpc/Makefile: Always pass --synthetic to nm if supported") removed the only conditional definition of $(NM), so we can revert our temporary bodge to avoid Kconfig recursion and go back to passing $(NM) through to the 'tools-support-relr.sh' when detecting support for RELR relocations. Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20 17:11:54 +08:00
def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
arm64: Add support for relocating the kernel with RELR relocations RELR is a relocation packing format for relative relocations. The format is described in a generic-abi proposal: https://groups.google.com/d/topic/generic-abi/bX460iggiKg/discussion The LLD linker can be instructed to pack relocations in the RELR format by passing the flag --pack-dyn-relocs=relr. This patch adds a new config option, CONFIG_RELR. Enabling this option instructs the linker to pack vmlinux's relative relocations in the RELR format, and causes the kernel to apply the relocations at startup along with the RELA relocations. RELA relocations still need to be applied because the linker will emit RELA relative relocations if they are unrepresentable in the RELR format (i.e. address not a multiple of 2). Enabling CONFIG_RELR reduces the size of a defconfig kernel image with CONFIG_RANDOMIZE_BASE by 3.5MB/16% uncompressed, or 550KB/5% compressed (lz4). Signed-off-by: Peter Collingbourne <pcc@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-01 09:18:42 +08:00
compiler-types.h: add asm_inline definition This adds an asm_inline macro which expands to "asm inline" [1] when the compiler supports it. This is currently gcc 9.1+, gcc 8.3 and (once released) gcc 7.5 [2]. It expands to just "asm" for other compilers. Using asm inline("foo") instead of asm("foo") overrules gcc's heuristic estimate of the size of the code represented by the asm() statement, and makes gcc use the minimum possible size instead. That can in turn affect gcc's inlining decisions. I wasn't sure whether to make this a function-like macro or not - this way, it can be combined with volatile as asm_inline volatile() but perhaps we'd prefer to spell that asm_inline_volatile() anyway. The Kconfig logic is taken from an RFC patch by Masahiro Yamada [3]. [1] Technically, asm __inline, since both inline and __inline__ are macros that attach various attributes, making gcc barf if one literally does "asm inline()". However, the third spelling __inline is available for referring to the bare keyword. [2] https://lore.kernel.org/lkml/20190907001411.GG9749@gate.crashing.org/ [3] https://lore.kernel.org/lkml/1544695154-15250-1-git-send-email-yamada.masahiro@socionext.com/ Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
2019-09-13 06:19:25 +08:00
config CC_HAS_ASM_INLINE
def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
kernel: constructor support Call constructors (gcc-generated initcall-like functions) during kernel start and module load. Constructors are e.g. used for gcov data initialization. Disable constructor support for usermode Linux to prevent conflicts with host glibc. Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Li Wei <W.Li@Sun.COM> Cc: Michael Ellerman <michaele@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com> Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 07:28:03 +08:00
config CONSTRUCTORS
bool
Revert "um: Enable CONFIG_CONSTRUCTORS" This reverts commit 786b2384bf1c ("um: Enable CONFIG_CONSTRUCTORS"). There are two issues with this commit, uncovered by Anton in tests on some (Debian) systems: 1) I completely forgot to call any constructors if CONFIG_CONSTRUCTORS isn't set. Don't recall now if it just wasn't needed on my system, or if I never tested this case. 2) With that fixed, it works - with CONFIG_CONSTRUCTORS *unset*. If I set CONFIG_CONSTRUCTORS, it fails again, which isn't totally unexpected since whatever wanted to run is likely to have to run before the kernel init etc. that calls the constructors in this case. Basically, some constructors that gcc emits (libc has?) need to run very early during init; the failure mode otherwise was that the ptrace fork test already failed: ---------------------- $ ./linux mem=512M Core dump limits : soft - 0 hard - NONE Checking that ptrace can change system call numbers...check_ptrace : child exited with exitcode 6, while expecting 0; status 0x67f Aborted ---------------------- Thinking more about this, it's clear that we simply cannot support CONFIG_CONSTRUCTORS in UML. All the cases we need now (gcov, kasan) involve not use of the __attribute__((constructor)), but instead some constructor code/entry generated by gcc. Therefore, we cannot distinguish between kernel constructors and system constructors. Thus, revert this commit. Cc: stable@vger.kernel.org [5.4+] Fixes: 786b2384bf1c ("um: Enable CONFIG_CONSTRUCTORS") Reported-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.co.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-12-05 00:43:46 +08:00
depends on !UML
kernel: constructor support Call constructors (gcc-generated initcall-like functions) during kernel start and module load. Constructors are e.g. used for gcov data initialization. Disable constructor support for usermode Linux to prevent conflicts with host glibc. Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Li Wei <W.Li@Sun.COM> Cc: Michael Ellerman <michaele@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com> Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 07:28:03 +08:00
irq_work: Add generic hardirq context callbacks Provide a mechanism that allows running code in IRQ context. It is most useful for NMI code that needs to interact with the rest of the system -- like wakeup a task to drain buffers. Perf currently has such a mechanism, so extract that and provide it as a generic feature, independent of perf so that others may also benefit. The IRQ context callback is generated through self-IPIs where possible, or on architectures like powerpc the decrementer (the built-in timer facility) is set to generate an interrupt immediately. Architectures that don't have anything like this get to do with a callback from the timer tick. These architectures can call irq_work_run() at the tail of any IRQ handlers that might enqueue such work (like the perf IRQ handler) to avoid undue latencies in processing the work. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [ various fixes ] Signed-off-by: Huang Ying <ying.huang@intel.com> LKML-Reference: <1287036094.7768.291.camel@yhuang-dev> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-14 14:01:34 +08:00
config IRQ_WORK
bool
scripts/sorttable: Rename 'sortextable' to 'sorttable' Use a more generic name for additional table sorting usecases, such as the upcoming ORC table sorting feature. This tool is not tied to exception table sorting anymore. No functional changes intended. [ mingo: Rewrote the changelog. ] Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: linux-kbuild@vger.kernel.org Link: https://lkml.kernel.org/r/20191204004633.88660-6-shile.zhang@linux.alibaba.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-12-04 08:46:31 +08:00
config BUILDTIME_TABLE_SORT
kbuild/extable: Hook up sortextable into the build system. Define a config variable BUILDTIME_EXTABLE_SORT to control build time sorting of the kernel's exception table. Patch Makefile to do the sorting when BUILDTIME_EXTABLE_SORT is selected. Signed-off-by: David Daney <david.daney@cavium.com> Link: http://lkml.kernel.org/r/1334872799-14589-4-git-send-email-ddaney.cavm@gmail.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-04-20 05:59:57 +08:00
bool
sched/core: Allow putting thread_info into task_struct If an arch opts in by setting CONFIG_THREAD_INFO_IN_TASK_STRUCT, then thread_info is defined as a single 'u32 flags' and is the first entry of task_struct. thread_info::task is removed (it serves no purpose if thread_info is embedded in task_struct), and thread_info::cpu gets its own slot in task_struct. This is heavily based on a patch written by Linus. Originally-from: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a0898196f0476195ca02713691a5037a14f2aac5.1473801993.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-14 05:29:24 +08:00
config THREAD_INFO_IN_TASK
bool
help
Select this to move thread_info off the stack into task_struct. To
make this work, an arch will need to remove all thread_info fields
except flags and fix any runtime bugs.
sched/core: Add try_get_task_stack() and put_task_stack() There are a few places in the kernel that access stack memory belonging to a different task. Before we can start freeing task stacks before the task_struct is freed, we need a way for those code paths to pin the stack. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/17a434f50ad3d77000104f21666575e10a9c1fbd.1474003868.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-16 13:45:43 +08:00
One subtle change that will be needed is to use try_get_task_stack()
and put_task_stack() in save_thread_stack_tsk() and get_wchan().
Kconfig: remove top level menu "Code maturity level options" Remove the top level menu "Code maturity level options", and moves its options into menu "General setup". This makes Kconfig less cluttered and easier to setup. Signed-off-by: Al Boldi <a1426z@gawab.com> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:23 +08:00
menu "General setup"
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config BROKEN
bool
config BROKEN_ON_SMP
bool
depends on BROKEN || !SMP
default y
config INIT_ENV_ARG_LIMIT
int
[PATCH] UML: fix the INIT_ENV_ARG_LIMIT dependencies Fix the INIT_ENV_ARG_LIMIT dependencies to what seems to have been intended. Spotted by Jean-Luc Leger. Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30 16:55:51 +08:00
default 32 if !UML
default 128 if UML
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
help
[PATCH] clarify help text for INIT_ENV_ARG_LIMIT Try to make the INIT_ENV_ARG_LIMIT help text more readable and understandable. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-31 07:01:46 +08:00
Maximum of each of the number of arguments and environment
variables passed to init from the kernel command line.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
build some drivers only when compile-testing Some drivers can be built on more platforms than they run on. This is a burden for users and distributors who package a kernel. They have to manually deselect some (for them useless) drivers when updating their configs via oldconfig. And yet, sometimes it is even impossible to disable the drivers without patching the kernel. Introduce a new config option COMPILE_TEST and make all those drivers to depend on the platform they run on, or on the COMPILE_TEST option. Now, when users/distributors choose COMPILE_TEST=n they will not have the drivers in their allmodconfig setups, but developers still can compile-test them with COMPILE_TEST=y. Now the drivers where we use this new option: * PTP_1588_CLOCK_PCH: The PCH EG20T is only compatible with Intel Atom processors so it should depend on x86. * FB_GEODE: Geode is 32-bit only so only enable it for X86_32. * USB_CHIPIDEA_IMX: The OF_DEVICE dependency will be met on powerpc systems -- which do not actually support the hardware via that method. * INTEL_MID_PTI: It is specific to the Penwell type of Intel Atom device. [v2] * remove EXPERT dependency [gregkh - remove chipidea portion, as it's incorrect, and also doesn't apply to my driver-core tree] Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: linux-usb@vger.kernel.org Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: linux-geode@lists.infradead.org Cc: linux-fbdev@vger.kernel.org Cc: Richard Cochran <richardcochran@gmail.com> Cc: netdev@vger.kernel.org Cc: Ben Hutchings <ben@decadent.org.uk> Cc: "Keller, Jacob E" <jacob.e.keller@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-22 16:56:24 +08:00
config COMPILE_TEST
bool "Compile also drivers which will not load"
init/Kconfig: make COMPILE_TEST depend on !UML UML is a bit special since it does not have iomem nor dma. That means a lot of drivers will not build if they miss a dependency on HAS_IOMEM. s390 used to have the same issues but since it gained PCI support UML is the only stranger. We are tired of patching dozens of new drivers after every merge window just to un-break allmod/yesconfig UML builds. One could argue that a decent driver has to know on what it depends and therefore a missing HAS_IOMEM dependency is a clear driver bug. But the dependency not obvious and not everyone does UML builds with COMPILE_TEST enabled when developing a device driver. A possible solution to make these builds succeed on UML would be providing stub functions for ioremap() and friends which fail upon runtime. Another one is simply disabling COMPILE_TEST for UML. Since it is the least hassle and does not force use to fake iomem support let's do the latter. Link: http://lkml.kernel.org/r/1466152995-28367-1-git-send-email-richard@nod.at Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-03 05:03:27 +08:00
depends on !UML
build some drivers only when compile-testing Some drivers can be built on more platforms than they run on. This is a burden for users and distributors who package a kernel. They have to manually deselect some (for them useless) drivers when updating their configs via oldconfig. And yet, sometimes it is even impossible to disable the drivers without patching the kernel. Introduce a new config option COMPILE_TEST and make all those drivers to depend on the platform they run on, or on the COMPILE_TEST option. Now, when users/distributors choose COMPILE_TEST=n they will not have the drivers in their allmodconfig setups, but developers still can compile-test them with COMPILE_TEST=y. Now the drivers where we use this new option: * PTP_1588_CLOCK_PCH: The PCH EG20T is only compatible with Intel Atom processors so it should depend on x86. * FB_GEODE: Geode is 32-bit only so only enable it for X86_32. * USB_CHIPIDEA_IMX: The OF_DEVICE dependency will be met on powerpc systems -- which do not actually support the hardware via that method. * INTEL_MID_PTI: It is specific to the Penwell type of Intel Atom device. [v2] * remove EXPERT dependency [gregkh - remove chipidea portion, as it's incorrect, and also doesn't apply to my driver-core tree] Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: linux-usb@vger.kernel.org Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: linux-geode@lists.infradead.org Cc: linux-fbdev@vger.kernel.org Cc: Richard Cochran <richardcochran@gmail.com> Cc: netdev@vger.kernel.org Cc: Ben Hutchings <ben@decadent.org.uk> Cc: "Keller, Jacob E" <jacob.e.keller@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-22 16:56:24 +08:00
default n
help
Some drivers can be compiled on a different platform than they are
intended to be run on. Despite they cannot be loaded there (or even
when they load they cannot be used due to missing HW support),
developers still, opposing to distributors, might want to build such
drivers to compile-test them.
If you are a developer and want to build everything available, say Y
here. If you are a user/distributor, say N here to exclude useless
drivers to be distributed.
kbuild: compile-test exported headers to ensure they are self-contained Multiple people have suggested compile-testing UAPI headers to ensure they can be really included from user-space. "make headers_check" is obviously not enough to catch bugs, and we often leak unresolved references to user-space. Use the new header-test-y syntax to implement it. Please note exported headers are compile-tested with a completely different set of compiler flags. The header search path is set to $(objtree)/usr/include since exported headers should not include unexported ones. We use -std=gnu89 for the kernel space since the kernel code highly depends on GNU extensions. On the other hand, UAPI headers should be written in more standardized C, so they are compiled with -std=c90. This will emit errors if C++ style comments, the keyword 'inline', etc. are used. Please use C style comments (/* ... */), '__inline__', etc. in UAPI headers. There is additional compiler requirement to enable this test because many of UAPI headers include <stdlib.h>, <sys/ioctl.h>, <sys/time.h>, etc. directly or indirectly. You cannot use kernel.org pre-built toolchains [1] since they lack <stdlib.h>. I reused CONFIG_CC_CAN_LINK to check the system header availability. The intention is slightly different, but a compiler that can link userspace programs provide system headers. For now, a lot of headers need to be excluded because they cannot be compiled standalone, but this is a good start point. [1] https://mirrors.edge.kernel.org/pub/tools/crosstool/index.html Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
2019-07-01 08:58:40 +08:00
config UAPI_HEADER_TEST
bool "Compile test UAPI headers"
kbuild: remove header compile test There are both positive and negative options about this feature. At first, I thought it was a good idea, but actually Linus stated a negative opinion (https://lkml.org/lkml/2019/9/29/227). I admit it is ugly and annoying. The baseline I'd like to keep is the compile-test of uapi headers. (Otherwise, kernel developers have no way to ensure the correctness of the exported headers.) I will maintain a small build rule in usr/include/Makefile. Remove the other header test functionality. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-07 15:14:40 +08:00
depends on HEADERS_INSTALL && CC_CAN_LINK
kbuild: compile-test exported headers to ensure they are self-contained Multiple people have suggested compile-testing UAPI headers to ensure they can be really included from user-space. "make headers_check" is obviously not enough to catch bugs, and we often leak unresolved references to user-space. Use the new header-test-y syntax to implement it. Please note exported headers are compile-tested with a completely different set of compiler flags. The header search path is set to $(objtree)/usr/include since exported headers should not include unexported ones. We use -std=gnu89 for the kernel space since the kernel code highly depends on GNU extensions. On the other hand, UAPI headers should be written in more standardized C, so they are compiled with -std=c90. This will emit errors if C++ style comments, the keyword 'inline', etc. are used. Please use C style comments (/* ... */), '__inline__', etc. in UAPI headers. There is additional compiler requirement to enable this test because many of UAPI headers include <stdlib.h>, <sys/ioctl.h>, <sys/time.h>, etc. directly or indirectly. You cannot use kernel.org pre-built toolchains [1] since they lack <stdlib.h>. I reused CONFIG_CC_CAN_LINK to check the system header availability. The intention is slightly different, but a compiler that can link userspace programs provide system headers. For now, a lot of headers need to be excluded because they cannot be compiled standalone, but this is a good start point. [1] https://mirrors.edge.kernel.org/pub/tools/crosstool/index.html Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
2019-07-01 08:58:40 +08:00
help
Compile test headers exported to user-space to ensure they are
self-contained, i.e. compilable as standalone units.
If you are a developer or tester and want to ensure the exported
headers are self-contained, say Y here. Otherwise, choose N.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config LOCALVERSION
string "Local version - append to kernel release"
help
Append an extra string to the end of your kernel version.
This will show up when you type uname, for example.
The string you set here will be appended after the contents of
any files with a filename matching localversion* in your
object and source tree, in that order. Your total string can
be a maximum of 64 characters.
[PATCH] kbuild: automatically append a short string to the version based upon the git commit If CONFIG_AUTO_LOCALVERSION is set, the user is using a git-based tree, and the current HEAD is not referred to by any tags in .git/refs/tags/, append -g and the first 8 characters of the commit to the version string. This makes it easier to use git-bisect, and/or to do a daily build, without trampling on your older, working builds, or accidentally setting up conflicting sets of modules. Signed-off-by: Ryan Anderson <ryan@michonline.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-07-31 16:57:49 +08:00
config LOCALVERSION_AUTO
bool "Automatically append version information to the version string"
default y
init/Kconfig: ban CONFIG_LOCALVERSION_AUTO with allmodconfig Doing patches with allmodconfig kernel compiled and committing stuff into local tree have unfortunate consequence: kernel version changes (as it should) leading to recompiling and relinking of several files even if they weren't touched (or interesting at all). This and "git-whatever" figuring out current version slow down compilation for no good reason. But lets face it, "allmodconfig" kernels don't care about kernel version, they are simply compile check guinea pigs. Make LOCALVERSION_AUTO depend on !COMPILE_TEST, so it doesn't sneak into allmodconfig .config. Link: http://lkml.kernel.org/r/20160707214954.GC31678@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-03 05:07:21 +08:00
depends on !COMPILE_TEST
[PATCH] kbuild: automatically append a short string to the version based upon the git commit If CONFIG_AUTO_LOCALVERSION is set, the user is using a git-based tree, and the current HEAD is not referred to by any tags in .git/refs/tags/, append -g and the first 8 characters of the commit to the version string. This makes it easier to use git-bisect, and/or to do a daily build, without trampling on your older, working builds, or accidentally setting up conflicting sets of modules. Signed-off-by: Ryan Anderson <ryan@michonline.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-07-31 16:57:49 +08:00
help
This will try to automatically determine if the current tree is a
kbuild: clarify the creation of the LOCALVERSION_AUTO string. Clarify the creation of the LOCALVERSION_AUTO string during kernel configuration, and fix a couple typoes while we're there. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-02 05:08:11 +08:00
release tree by looking for git tags that belong to the current
top of tree revision.
[PATCH] kbuild: automatically append a short string to the version based upon the git commit If CONFIG_AUTO_LOCALVERSION is set, the user is using a git-based tree, and the current HEAD is not referred to by any tags in .git/refs/tags/, append -g and the first 8 characters of the commit to the version string. This makes it easier to use git-bisect, and/or to do a daily build, without trampling on your older, working builds, or accidentally setting up conflicting sets of modules. Signed-off-by: Ryan Anderson <ryan@michonline.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-07-31 16:57:49 +08:00
A string of the format -gxxxxxxxx will be added to the localversion
kbuild: clarify the creation of the LOCALVERSION_AUTO string. Clarify the creation of the LOCALVERSION_AUTO string during kernel configuration, and fix a couple typoes while we're there. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-02 05:08:11 +08:00
if a git-based tree is found. The string generated by this will be
[PATCH] kbuild: automatically append a short string to the version based upon the git commit If CONFIG_AUTO_LOCALVERSION is set, the user is using a git-based tree, and the current HEAD is not referred to by any tags in .git/refs/tags/, append -g and the first 8 characters of the commit to the version string. This makes it easier to use git-bisect, and/or to do a daily build, without trampling on your older, working builds, or accidentally setting up conflicting sets of modules. Signed-off-by: Ryan Anderson <ryan@michonline.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-07-31 16:57:49 +08:00
appended after any matching localversion* files, and after the value
kbuild: clarify the creation of the LOCALVERSION_AUTO string. Clarify the creation of the LOCALVERSION_AUTO string during kernel configuration, and fix a couple typoes while we're there. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-02 05:08:11 +08:00
set in CONFIG_LOCALVERSION.
[PATCH] kbuild: automatically append a short string to the version based upon the git commit If CONFIG_AUTO_LOCALVERSION is set, the user is using a git-based tree, and the current HEAD is not referred to by any tags in .git/refs/tags/, append -g and the first 8 characters of the commit to the version string. This makes it easier to use git-bisect, and/or to do a daily build, without trampling on your older, working builds, or accidentally setting up conflicting sets of modules. Signed-off-by: Ryan Anderson <ryan@michonline.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-07-31 16:57:49 +08:00
kbuild: clarify the creation of the LOCALVERSION_AUTO string. Clarify the creation of the LOCALVERSION_AUTO string during kernel configuration, and fix a couple typoes while we're there. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-02 05:08:11 +08:00
(The actual string used here is the first eight characters produced
by running the command:
$ git rev-parse --verify HEAD
which is done within the script "scripts/setlocalversion".)
[PATCH] kbuild: automatically append a short string to the version based upon the git commit If CONFIG_AUTO_LOCALVERSION is set, the user is using a git-based tree, and the current HEAD is not referred to by any tags in .git/refs/tags/, append -g and the first 8 characters of the commit to the version string. This makes it easier to use git-bisect, and/or to do a daily build, without trampling on your older, working builds, or accidentally setting up conflicting sets of modules. Signed-off-by: Ryan Anderson <ryan@michonline.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-07-31 16:57:49 +08:00
kbuild: Add build salt to the kernel and modules In Fedora, the debug information is packaged separately (foo-debuginfo) and can be installed separately. There's been a long standing issue where only one version of a debuginfo info package can be installed at a time. There's been an effort for Fedora for parallel debuginfo to rectify this problem. Part of the requirement to allow parallel debuginfo to work is that build ids are unique between builds. The existing upstream rpm implementation ensures this by re-calculating the build-id using the version and release as a seed. This doesn't work 100% for the kernel because of the vDSO which is its own binary and doesn't get updated when embedded. Fix this by adding some data in an ELF note for both the kernel and modules. The data is controlled via a Kconfig option so distributions can set it to an appropriate value to ensure uniqueness between builds. Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-06 08:49:37 +08:00
config BUILD_SALT
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
string "Build ID Salt"
default ""
help
The build ID is used to link binaries and their debug info. Setting
this option will use the value in the calculation of the build id.
This is mostly useful for distributions which want to ensure the
build is unique between builds. It's safe to leave the default.
kbuild: Add build salt to the kernel and modules In Fedora, the debug information is packaged separately (foo-debuginfo) and can be installed separately. There's been a long standing issue where only one version of a debuginfo info package can be installed at a time. There's been an effort for Fedora for parallel debuginfo to rectify this problem. Part of the requirement to allow parallel debuginfo to work is that build ids are unique between builds. The existing upstream rpm implementation ensures this by re-calculating the build-id using the version and release as a seed. This doesn't work 100% for the kernel because of the vDSO which is its own binary and doesn't get updated when embedded. Fix this by adding some data in an ELF note for both the kernel and modules. The data is controlled via a Kconfig option so distributions can set it to an appropriate value to ensure uniqueness between builds. Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-06 08:49:37 +08:00
bzip2/lzma: make config machinery an arch configurable Impact: Bug fix (we should not show this menu on irrelevant architectures) Make the config machinery to drive the gzip/bzip2/lzma selection dependent on the architecture advertising HAVE_KERNEL_* so that we don't display this for architectures where it doesn't matter. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 07:41:25 +08:00
config HAVE_KERNEL_GZIP
bool
config HAVE_KERNEL_BZIP2
bool
config HAVE_KERNEL_LZMA
bool
decompressors: add boot-time XZ support This implements the API defined in <linux/decompress/generic.h> which is used for kernel, initramfs, and initrd decompression. This patch together with the first patch is enough for XZ-compressed initramfs and initrd; XZ-compressed kernel will need arch-specific changes. The buffering requirements described in decompress_unxz.c are stricter than with gzip, so the relevant changes should be done to the arch-specific code when adding support for XZ-compressed kernel. Similarly, the heap size in arch-specific pre-boot code may need to be increased (30 KiB is enough). The XZ decompressor needs memmove(), memeq() (memcmp() == 0), and memzero() (memset(ptr, 0, size)), which aren't available in all arch-specific pre-boot environments. I'm including simple versions in decompress_unxz.c, but a cleaner solution would naturally be nicer. Signed-off-by: Lasse Collin <lasse.collin@tukaani.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alain Knaff <alain@knaff.lu> Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com> Cc: Phillip Lougher <phillip@lougher.demon.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 09:01:23 +08:00
config HAVE_KERNEL_XZ
bool
lib: add support for LZO-compressed kernels This patch series adds generic support for creating and extracting LZO-compressed kernel images, as well as support for using such images on the x86 and ARM architectures, and support for creating and using LZO-compressed initrd and initramfs images. Russell King said: : Testing on a Cortex A9 model: : - lzo decompressor is 65% of the time gzip takes to decompress a kernel : - lzo kernel is 9% larger than a gzip kernel : : which I'm happy to say confirms your figures when comparing the two. : : However, when comparing your new gzip code to the old gzip code: : - new is 99% of the size of the old code : - new takes 42% of the time to decompress than the old code : : What this means is that for a proper comparison, the results get even better: : - lzo is 7.5% larger than the old gzip'd kernel image : - lzo takes 28% of the time that the old gzip code took : : So the expense seems definitely worth the effort. The only reason I : can think of ever using gzip would be if you needed the additional : compression (eg, because you have limited flash to store the image.) : : I would argue that the default for ARM should therefore be LZO. This patch: The lzo compressor is worse than gzip at compression, but faster at extraction. Here are some figures for an ARM board I'm working on: Uncompressed size: 3.24Mo gzip 1.61Mo 0.72s lzo 1.75Mo 0.48s So for a compression ratio that is still relatively close to gzip, it's much faster to extract, at least in that case. This part contains: - Makefile routine to support lzo compression - Fixes to the existing lzo compressor so that it can be used in compressed kernels - wrapper around the existing lzo1x_decompress, as it only extracts one block at a time, while we need to extract a whole file here - config dialog for kernel compression [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: cleanup] Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com> Tested-by: Wu Zhangjin <wuzhangjin@gmail.com> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Tested-by: Russell King <rmk@arm.linux.org.uk> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-09 06:42:42 +08:00
config HAVE_KERNEL_LZO
bool
lib: add support for LZ4-compressed kernel Add support for extracting LZ4-compressed kernel images, as well as LZ4-compressed ramdisk images in the kernel boot process. Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Florian Fainelli <florian@openwrt.org> Cc: Yann Collet <yann.collet.73@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 07:01:46 +08:00
config HAVE_KERNEL_LZ4
bool
init/Kconfig: add an option for uncompressed kernel Add "None" as the kernel compression mode. This option is useful for debugging the kernel in slow simulation environments, where decompressing and moving the kernel is awfully slow. Uncompressed kernel implementation might allow early boot code to skip the decompressor and jump right at uncompressed kernel image entry point. Platforms implementing that should define HAVE_KERNEL_UNCOMPRESSED. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-06-13 03:26:35 +08:00
config HAVE_KERNEL_UNCOMPRESSED
bool
bzip2/lzma: config and initramfs support for bzip2/lzma decompression Impact: New code for initramfs decompression, new features This is the second part of the bzip2/lzma patch The bzip patch is based on an idea by Christian Ludwig, includes support for compressing the kernel with bzip2 or lzma rather than gzip. Both compressors give smaller sizes than gzip. Lzma's decompresses faster than bzip2. It also supports ramdisks and initramfs' compressed using these two compressors. The functionality has been successfully used for a couple of years by the udpcast project This version applies to "tip" kernel 2.6.28 This part contains: - support for new compressions (bzip2 and lzma) in initramfs and old-style ramdisk - config dialog for kernel compression (but new kernel compressions not yet supported) Signed-off-by: Alain Knaff <alain@knaff.lu> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 05:46:17 +08:00
choice
bzip2/lzma: make config machinery an arch configurable Impact: Bug fix (we should not show this menu on irrelevant architectures) Make the config machinery to drive the gzip/bzip2/lzma selection dependent on the architecture advertising HAVE_KERNEL_* so that we don't display this for architectures where it doesn't matter. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 07:41:25 +08:00
prompt "Kernel compression mode"
default KERNEL_GZIP
init/Kconfig: add an option for uncompressed kernel Add "None" as the kernel compression mode. This option is useful for debugging the kernel in slow simulation environments, where decompressing and moving the kernel is awfully slow. Uncompressed kernel implementation might allow early boot code to skip the decompressor and jump right at uncompressed kernel image entry point. Platforms implementing that should define HAVE_KERNEL_UNCOMPRESSED. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-06-13 03:26:35 +08:00
depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_UNCOMPRESSED
bzip2/lzma: make config machinery an arch configurable Impact: Bug fix (we should not show this menu on irrelevant architectures) Make the config machinery to drive the gzip/bzip2/lzma selection dependent on the architecture advertising HAVE_KERNEL_* so that we don't display this for architectures where it doesn't matter. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 07:41:25 +08:00
help
bzip2/lzma: config and initramfs support for bzip2/lzma decompression Impact: New code for initramfs decompression, new features This is the second part of the bzip2/lzma patch The bzip patch is based on an idea by Christian Ludwig, includes support for compressing the kernel with bzip2 or lzma rather than gzip. Both compressors give smaller sizes than gzip. Lzma's decompresses faster than bzip2. It also supports ramdisks and initramfs' compressed using these two compressors. The functionality has been successfully used for a couple of years by the udpcast project This version applies to "tip" kernel 2.6.28 This part contains: - support for new compressions (bzip2 and lzma) in initramfs and old-style ramdisk - config dialog for kernel compression (but new kernel compressions not yet supported) Signed-off-by: Alain Knaff <alain@knaff.lu> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 05:46:17 +08:00
The linux kernel is a kind of self-extracting executable.
Several compression algorithms are available, which differ
in efficiency, compression and decompression speed.
Compression speed is only relevant when building a kernel.
Decompression speed is relevant at each boot.
If you have any problems with bzip2 or lzma compressed
kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
version of this functionality (bzip2 only), for 2.4, was
supplied by Christian Ludwig)
High compression options are mostly useful for users, who
are low on disk space (embedded systems), but for whom ram
size matters less.
If in doubt, select 'gzip'
config KERNEL_GZIP
bzip2/lzma: make config machinery an arch configurable Impact: Bug fix (we should not show this menu on irrelevant architectures) Make the config machinery to drive the gzip/bzip2/lzma selection dependent on the architecture advertising HAVE_KERNEL_* so that we don't display this for architectures where it doesn't matter. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 07:41:25 +08:00
bool "Gzip"
depends on HAVE_KERNEL_GZIP
help
lib: add support for LZO-compressed kernels This patch series adds generic support for creating and extracting LZO-compressed kernel images, as well as support for using such images on the x86 and ARM architectures, and support for creating and using LZO-compressed initrd and initramfs images. Russell King said: : Testing on a Cortex A9 model: : - lzo decompressor is 65% of the time gzip takes to decompress a kernel : - lzo kernel is 9% larger than a gzip kernel : : which I'm happy to say confirms your figures when comparing the two. : : However, when comparing your new gzip code to the old gzip code: : - new is 99% of the size of the old code : - new takes 42% of the time to decompress than the old code : : What this means is that for a proper comparison, the results get even better: : - lzo is 7.5% larger than the old gzip'd kernel image : - lzo takes 28% of the time that the old gzip code took : : So the expense seems definitely worth the effort. The only reason I : can think of ever using gzip would be if you needed the additional : compression (eg, because you have limited flash to store the image.) : : I would argue that the default for ARM should therefore be LZO. This patch: The lzo compressor is worse than gzip at compression, but faster at extraction. Here are some figures for an ARM board I'm working on: Uncompressed size: 3.24Mo gzip 1.61Mo 0.72s lzo 1.75Mo 0.48s So for a compression ratio that is still relatively close to gzip, it's much faster to extract, at least in that case. This part contains: - Makefile routine to support lzo compression - Fixes to the existing lzo compressor so that it can be used in compressed kernels - wrapper around the existing lzo1x_decompress, as it only extracts one block at a time, while we need to extract a whole file here - config dialog for kernel compression [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: cleanup] Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com> Tested-by: Wu Zhangjin <wuzhangjin@gmail.com> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Tested-by: Russell King <rmk@arm.linux.org.uk> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-09 06:42:42 +08:00
The old and tried gzip compression. It provides a good balance
between compression ratio and decompression speed.
bzip2/lzma: config and initramfs support for bzip2/lzma decompression Impact: New code for initramfs decompression, new features This is the second part of the bzip2/lzma patch The bzip patch is based on an idea by Christian Ludwig, includes support for compressing the kernel with bzip2 or lzma rather than gzip. Both compressors give smaller sizes than gzip. Lzma's decompresses faster than bzip2. It also supports ramdisks and initramfs' compressed using these two compressors. The functionality has been successfully used for a couple of years by the udpcast project This version applies to "tip" kernel 2.6.28 This part contains: - support for new compressions (bzip2 and lzma) in initramfs and old-style ramdisk - config dialog for kernel compression (but new kernel compressions not yet supported) Signed-off-by: Alain Knaff <alain@knaff.lu> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 05:46:17 +08:00
config KERNEL_BZIP2
bool "Bzip2"
bzip2/lzma: make config machinery an arch configurable Impact: Bug fix (we should not show this menu on irrelevant architectures) Make the config machinery to drive the gzip/bzip2/lzma selection dependent on the architecture advertising HAVE_KERNEL_* so that we don't display this for architectures where it doesn't matter. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 07:41:25 +08:00
depends on HAVE_KERNEL_BZIP2
bzip2/lzma: config and initramfs support for bzip2/lzma decompression Impact: New code for initramfs decompression, new features This is the second part of the bzip2/lzma patch The bzip patch is based on an idea by Christian Ludwig, includes support for compressing the kernel with bzip2 or lzma rather than gzip. Both compressors give smaller sizes than gzip. Lzma's decompresses faster than bzip2. It also supports ramdisks and initramfs' compressed using these two compressors. The functionality has been successfully used for a couple of years by the udpcast project This version applies to "tip" kernel 2.6.28 This part contains: - support for new compressions (bzip2 and lzma) in initramfs and old-style ramdisk - config dialog for kernel compression (but new kernel compressions not yet supported) Signed-off-by: Alain Knaff <alain@knaff.lu> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 05:46:17 +08:00
help
Its compression ratio and speed is intermediate.
kconfig: update compression algorithm info There have been new compression algorithms added without updating nearby relevant descriptive text that refers to (a) the number of compression algorithms and (b) the most recent one. Fix these inconsistencies. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Reported-by: <qasdfgtyuiop@gmail.com> Cc: Lasse Collin <lasse.collin@tukaani.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Alain Knaff <alain@knaff.lu> Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01 07:26:46 +08:00
Decompression speed is slowest among the choices. The kernel
bzip2/lzma: make config machinery an arch configurable Impact: Bug fix (we should not show this menu on irrelevant architectures) Make the config machinery to drive the gzip/bzip2/lzma selection dependent on the architecture advertising HAVE_KERNEL_* so that we don't display this for architectures where it doesn't matter. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 07:41:25 +08:00
size is about 10% smaller with bzip2, in comparison to gzip.
Bzip2 uses a large amount of memory. For modern kernels you
will need at least 8MB RAM or more for booting.
bzip2/lzma: config and initramfs support for bzip2/lzma decompression Impact: New code for initramfs decompression, new features This is the second part of the bzip2/lzma patch The bzip patch is based on an idea by Christian Ludwig, includes support for compressing the kernel with bzip2 or lzma rather than gzip. Both compressors give smaller sizes than gzip. Lzma's decompresses faster than bzip2. It also supports ramdisks and initramfs' compressed using these two compressors. The functionality has been successfully used for a couple of years by the udpcast project This version applies to "tip" kernel 2.6.28 This part contains: - support for new compressions (bzip2 and lzma) in initramfs and old-style ramdisk - config dialog for kernel compression (but new kernel compressions not yet supported) Signed-off-by: Alain Knaff <alain@knaff.lu> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 05:46:17 +08:00
config KERNEL_LZMA
bzip2/lzma: make config machinery an arch configurable Impact: Bug fix (we should not show this menu on irrelevant architectures) Make the config machinery to drive the gzip/bzip2/lzma selection dependent on the architecture advertising HAVE_KERNEL_* so that we don't display this for architectures where it doesn't matter. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 07:41:25 +08:00
bool "LZMA"
depends on HAVE_KERNEL_LZMA
help
kconfig: update compression algorithm info There have been new compression algorithms added without updating nearby relevant descriptive text that refers to (a) the number of compression algorithms and (b) the most recent one. Fix these inconsistencies. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Reported-by: <qasdfgtyuiop@gmail.com> Cc: Lasse Collin <lasse.collin@tukaani.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Alain Knaff <alain@knaff.lu> Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01 07:26:46 +08:00
This compression algorithm's ratio is best. Decompression speed
is between gzip and bzip2. Compression is slowest.
The kernel size is about 33% smaller with LZMA in comparison to gzip.
bzip2/lzma: config and initramfs support for bzip2/lzma decompression Impact: New code for initramfs decompression, new features This is the second part of the bzip2/lzma patch The bzip patch is based on an idea by Christian Ludwig, includes support for compressing the kernel with bzip2 or lzma rather than gzip. Both compressors give smaller sizes than gzip. Lzma's decompresses faster than bzip2. It also supports ramdisks and initramfs' compressed using these two compressors. The functionality has been successfully used for a couple of years by the udpcast project This version applies to "tip" kernel 2.6.28 This part contains: - support for new compressions (bzip2 and lzma) in initramfs and old-style ramdisk - config dialog for kernel compression (but new kernel compressions not yet supported) Signed-off-by: Alain Knaff <alain@knaff.lu> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 05:46:17 +08:00
decompressors: add boot-time XZ support This implements the API defined in <linux/decompress/generic.h> which is used for kernel, initramfs, and initrd decompression. This patch together with the first patch is enough for XZ-compressed initramfs and initrd; XZ-compressed kernel will need arch-specific changes. The buffering requirements described in decompress_unxz.c are stricter than with gzip, so the relevant changes should be done to the arch-specific code when adding support for XZ-compressed kernel. Similarly, the heap size in arch-specific pre-boot code may need to be increased (30 KiB is enough). The XZ decompressor needs memmove(), memeq() (memcmp() == 0), and memzero() (memset(ptr, 0, size)), which aren't available in all arch-specific pre-boot environments. I'm including simple versions in decompress_unxz.c, but a cleaner solution would naturally be nicer. Signed-off-by: Lasse Collin <lasse.collin@tukaani.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alain Knaff <alain@knaff.lu> Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com> Cc: Phillip Lougher <phillip@lougher.demon.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 09:01:23 +08:00
config KERNEL_XZ
bool "XZ"
depends on HAVE_KERNEL_XZ
help
XZ uses the LZMA2 algorithm and instruction set specific
BCJ filters which can improve compression ratio of executable
code. The size of the kernel is about 30% smaller with XZ in
comparison to gzip. On architectures for which there is a BCJ
filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
will create a few percent smaller kernel than plain LZMA.
The speed is about the same as with LZMA: The decompression
speed of XZ is better than that of bzip2 but worse than gzip
and LZO. Compression is slow.
lib: add support for LZO-compressed kernels This patch series adds generic support for creating and extracting LZO-compressed kernel images, as well as support for using such images on the x86 and ARM architectures, and support for creating and using LZO-compressed initrd and initramfs images. Russell King said: : Testing on a Cortex A9 model: : - lzo decompressor is 65% of the time gzip takes to decompress a kernel : - lzo kernel is 9% larger than a gzip kernel : : which I'm happy to say confirms your figures when comparing the two. : : However, when comparing your new gzip code to the old gzip code: : - new is 99% of the size of the old code : - new takes 42% of the time to decompress than the old code : : What this means is that for a proper comparison, the results get even better: : - lzo is 7.5% larger than the old gzip'd kernel image : - lzo takes 28% of the time that the old gzip code took : : So the expense seems definitely worth the effort. The only reason I : can think of ever using gzip would be if you needed the additional : compression (eg, because you have limited flash to store the image.) : : I would argue that the default for ARM should therefore be LZO. This patch: The lzo compressor is worse than gzip at compression, but faster at extraction. Here are some figures for an ARM board I'm working on: Uncompressed size: 3.24Mo gzip 1.61Mo 0.72s lzo 1.75Mo 0.48s So for a compression ratio that is still relatively close to gzip, it's much faster to extract, at least in that case. This part contains: - Makefile routine to support lzo compression - Fixes to the existing lzo compressor so that it can be used in compressed kernels - wrapper around the existing lzo1x_decompress, as it only extracts one block at a time, while we need to extract a whole file here - config dialog for kernel compression [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: cleanup] Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com> Tested-by: Wu Zhangjin <wuzhangjin@gmail.com> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Tested-by: Russell King <rmk@arm.linux.org.uk> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-09 06:42:42 +08:00
config KERNEL_LZO
bool "LZO"
depends on HAVE_KERNEL_LZO
help
kconfig: update compression algorithm info There have been new compression algorithms added without updating nearby relevant descriptive text that refers to (a) the number of compression algorithms and (b) the most recent one. Fix these inconsistencies. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Reported-by: <qasdfgtyuiop@gmail.com> Cc: Lasse Collin <lasse.collin@tukaani.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Alain Knaff <alain@knaff.lu> Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-01 07:26:46 +08:00
Its compression ratio is the poorest among the choices. The kernel
Kconfig: delete duplicate word Deleted a word which apeared twice. Signed-off-by: Stephan Sperber <sperberstephan@googlemail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-07-14 17:23:08 +08:00
size is about 10% bigger than gzip; however its speed
lib: add support for LZO-compressed kernels This patch series adds generic support for creating and extracting LZO-compressed kernel images, as well as support for using such images on the x86 and ARM architectures, and support for creating and using LZO-compressed initrd and initramfs images. Russell King said: : Testing on a Cortex A9 model: : - lzo decompressor is 65% of the time gzip takes to decompress a kernel : - lzo kernel is 9% larger than a gzip kernel : : which I'm happy to say confirms your figures when comparing the two. : : However, when comparing your new gzip code to the old gzip code: : - new is 99% of the size of the old code : - new takes 42% of the time to decompress than the old code : : What this means is that for a proper comparison, the results get even better: : - lzo is 7.5% larger than the old gzip'd kernel image : - lzo takes 28% of the time that the old gzip code took : : So the expense seems definitely worth the effort. The only reason I : can think of ever using gzip would be if you needed the additional : compression (eg, because you have limited flash to store the image.) : : I would argue that the default for ARM should therefore be LZO. This patch: The lzo compressor is worse than gzip at compression, but faster at extraction. Here are some figures for an ARM board I'm working on: Uncompressed size: 3.24Mo gzip 1.61Mo 0.72s lzo 1.75Mo 0.48s So for a compression ratio that is still relatively close to gzip, it's much faster to extract, at least in that case. This part contains: - Makefile routine to support lzo compression - Fixes to the existing lzo compressor so that it can be used in compressed kernels - wrapper around the existing lzo1x_decompress, as it only extracts one block at a time, while we need to extract a whole file here - config dialog for kernel compression [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: cleanup] Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com> Tested-by: Wu Zhangjin <wuzhangjin@gmail.com> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Tested-by: Russell King <rmk@arm.linux.org.uk> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-09 06:42:42 +08:00
(both compression and decompression) is the fastest.
lib: add support for LZ4-compressed kernel Add support for extracting LZ4-compressed kernel images, as well as LZ4-compressed ramdisk images in the kernel boot process. Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Florian Fainelli <florian@openwrt.org> Cc: Yann Collet <yann.collet.73@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 07:01:46 +08:00
config KERNEL_LZ4
bool "LZ4"
depends on HAVE_KERNEL_LZ4
help
LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
A preliminary version of LZ4 de/compression tool is available at
<https://code.google.com/p/lz4/>.
Its compression ratio is worse than LZO. The size of the kernel
is about 8% bigger than LZO. But the decompression speed is
faster than LZO.
init/Kconfig: add an option for uncompressed kernel Add "None" as the kernel compression mode. This option is useful for debugging the kernel in slow simulation environments, where decompressing and moving the kernel is awfully slow. Uncompressed kernel implementation might allow early boot code to skip the decompressor and jump right at uncompressed kernel image entry point. Platforms implementing that should define HAVE_KERNEL_UNCOMPRESSED. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-06-13 03:26:35 +08:00
config KERNEL_UNCOMPRESSED
bool "None"
depends on HAVE_KERNEL_UNCOMPRESSED
help
Produce uncompressed kernel image. This option is usually not what
you want. It is useful for debugging the kernel in slow simulation
environments, where decompressing and moving the kernel is awfully
slow. This option allows early boot code to skip the decompressor
and jump right at uncompressed kernel image.
bzip2/lzma: config and initramfs support for bzip2/lzma decompression Impact: New code for initramfs decompression, new features This is the second part of the bzip2/lzma patch The bzip patch is based on an idea by Christian Ludwig, includes support for compressing the kernel with bzip2 or lzma rather than gzip. Both compressors give smaller sizes than gzip. Lzma's decompresses faster than bzip2. It also supports ramdisks and initramfs' compressed using these two compressors. The functionality has been successfully used for a couple of years by the udpcast project This version applies to "tip" kernel 2.6.28 This part contains: - support for new compressions (bzip2 and lzma) in initramfs and old-style ramdisk - config dialog for kernel compression (but new kernel compressions not yet supported) Signed-off-by: Alain Knaff <alain@knaff.lu> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-05 05:46:17 +08:00
endchoice
init: allow distribution configuration of default init Some init systems (eg. systemd) have init at their own paths, for example, /usr/lib/systemd/systemd. A compatibility symlink to one of the hardcoded init paths is provided by another package, usually named something like systemd-sysvcompat or similar. Currently distro maintainers who are hands-off on the bootloader are more or less required to include those compatibility links as part of their base distribution, because it's hard to migrate away from them since there's a risk some users will not get the message to set init= on the kernel command line appropriately. Moreover, for distributions where the init system is something the distribution itself is opinionated about (eg. Arch, which has systemd in the required `base` package), we could usually reasonably configure this ahead of time when building the distribution kernel. However, we currently simply don't have any way to configure the kernel to do this. Here's an example discussion where removing sysvcompat was discussed by distro maintainers[0]. This patch adds a new Kconfig tunable, CONFIG_DEFAULT_INIT, which if set is tried before the hardcoded fallback list. So the order of precedence is now thus: 1. init= on command line (on failure: panic) 2. CONFIG_DEFAULT_INIT (on failure: try #3) 3. Hardcoded fallback list (on failure: panic) This new config parameter will allow distribution maintainers to move away from these compatibility links safely, without having to worry that their users might not have the right init=. There are also two other benefits of this over having the distribution maintain a symlink: 1. One of the value propositions over simply having distributions maintain a /sbin/init symlink via a package is that it also frees distributions which have a preferred default, but not mandatory, init system from having their package manager fight with their users for control of /{s,}bin/init. Instead, the distribution simply makes their preference known in CONFIG_DEFAULT_INIT, and if the user installs another init system and uninstalls the default one they can still make use of /{s,}bin/init and friends for their own uses. This makes more cases Just Work(tm) without the user having to perform extra configuration via init=. 2. Since before this we don't know which path the distribution actually _intends_ to serve init from, we don't pr_err if it is simply missing, and usually will just silently put the user in a /bin/sh shell. Now that the distribution can make a declaration of intent, we can be more vocal when this init system fails to launch for any reason, even if it's simply because no file exists at that location, speeding up the palaver of init/mount dependency/etc debugging a bit. [0]: https://lists.archlinux.org/pipermail/arch-dev-public/2019-January/029435.html Signed-off-by: Chris Down <chris@chrisdown.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Link: http://lkml.kernel.org/r/20200522160234.GA1487022@chrisdown.name Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-05 07:50:53 +08:00
config DEFAULT_INIT
string "Default init path"
default ""
help
This option determines the default init for the system if no init=
option is passed on the kernel command line. If the requested path is
not present, we will still then move on to attempting further
locations (e.g. /sbin/init, etc). If this is empty, we will just use
the fallback list when init= is not passed.
uts: make default hostname configurable, rather than always using "(none)" The "hostname" tool falls back to setting the hostname to "localhost" if /etc/hostname does not exist. Distribution init scripts have the same fallback. However, if userspace never calls sethostname, such as when booting with init=/bin/sh, or otherwise booting a minimal system without the usual init scripts, the default hostname of "(none)" remains, unhelpfully appearing in various places such as prompts ("root@(none):~#") and logs. Furthermore, "(none)" doesn't typically resolve to anything useful. Make the default hostname configurable. This removes the need for the standard fallback, provides a useful default for systems that never call sethostname, and makes minimal systems that much more useful with less configuration. Distributions could choose to use "localhost" here to avoid the fallback, while embedded systems may wish to use a specific target hostname. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: David Miller <davem@davemloft.net> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Kel Modderman <kel@otaku42.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-16 06:08:28 +08:00
config DEFAULT_HOSTNAME
string "Default hostname"
default "(none)"
help
This option determines the default system hostname before userspace
calls sethostname(2). The kernel traditionally uses "(none)" here,
but you may wish to use a different default here to make a minimal
system more usable with less configuration.
kconfig: remove duplicate SWAP symbol defintions microblaze and nios2 define their own always n SWAP symbols. Remove those and let the generic defintion do the right thing by adding a new symbol to disable swap entirely. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-31 19:39:29 +08:00
#
# For some reason microblaze and nios2 hard code SWAP=n. Hopefully we can
# add proper SWAP support to them, in which case this can be remove.
#
config ARCH_NO_SWAP
bool
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config SWAP
bool "Support for paging of anonymous memory (swap)"
kconfig: remove duplicate SWAP symbol defintions microblaze and nios2 define their own always n SWAP symbols. Remove those and let the generic defintion do the right thing by adding a new symbol to disable swap entirely. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-31 19:39:29 +08:00
depends on MMU && BLOCK && !ARCH_NO_SWAP
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
default y
help
This option allows you to choose whether you want to have support
Spelling fix in init/Kconfig for the help of CONFIG_SWAP Trivial spelling fix s/socalled/so called/ Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-01-15 09:40:08 +08:00
for so called swap devices or swap files in your kernel that are
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
used to provide more virtual memory than the actual RAM present
in your computer. If unsure say Y.
config SYSVIPC
bool "System V IPC"
treewide: replace '---help---' in Kconfig files with 'help' Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 00:50:22 +08:00
help
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
Inter Process Communication is a suite of library functions and
system calls which let processes (running programs) synchronize and
exchange information. It is generally considered to be a good thing,
and some programs won't run unless you say Y here. In particular, if
you want to run the DOS emulator dosemu under Linux (read the
DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
you'll need to say Y here.
You can find documentation about IPC with "info ipc" and also in
section 6.4 of the Linux Programmer's Guide, available from
<http://www.tldp.org/guides.html>.
[PATCH] sysctl: move SYSV IPC sysctls to their own file This is just a simple cleanup to keep kernel/sysctl.c from getting to crowded with special cases, and by keeping all of the ipc logic to together it makes the code a little more readable. [gcoady.lk@gmail.com: build fix] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Signed-off-by: Grant Coady <gcoady.lk@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 16:34:06 +08:00
config SYSVIPC_SYSCTL
bool
depends on SYSVIPC
depends on SYSCTL
default y
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config POSIX_MQUEUE
bool "POSIX Message Queues"
init: remove depends on CONFIG_EXPERIMENTAL The CONFIG_EXPERIMENTAL config item has not carried much meaning for a while now and is almost always enabled by default. As agreed during the Linux kernel summit, remove it from any "depends on" lines in Kconfigs. CC: "Eric W. Biederman" <ebiederm@xmission.com> CC: Serge Hallyn <serge.hallyn@canonical.com> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2012-10-03 02:19:29 +08:00
depends on NET
treewide: replace '---help---' in Kconfig files with 'help' Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 00:50:22 +08:00
help
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
POSIX variant of message queues is a part of IPC. In POSIX message
queues every message has a priority which decides about succession
of receiving it by a process. If you want to compile and run
programs written e.g. for Solaris with use of its POSIX message
Kconfig: Remove reference to external mqueue library Remove the reference to an external mqueue library since that was merged into glibc in 2004. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2007-05-09 13:25:13 +08:00
queues (functions mq_*) say Y here.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
POSIX message queues are visible as a filesystem called 'mqueue'
and can be mounted somewhere if you want to do filesystem
operations on message queues.
If unsure, say Y.
namespaces: mqueue namespace: adapt sysctl Largely inspired from ipc/ipc_sysctl.c. This patch isolates the mqueue sysctl stuff in its own file. [akpm@linux-foundation.org: build fix] Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07 10:01:11 +08:00
config POSIX_MQUEUE_SYSCTL
bool
depends on POSIX_MQUEUE
depends on SYSCTL
default y
pipe: Add general notification queue support Make it possible to have a general notification queue built on top of a standard pipe. Notifications are 'spliced' into the pipe and then read out. splice(), vmsplice() and sendfile() are forbidden on pipes used for notifications as post_one_notification() cannot take pipe->mutex. This means that notifications could be posted in between individual pipe buffers, making iov_iter_revert() difficult to effect. The way the notification queue is used is: (1) An application opens a pipe with a special flag and indicates the number of messages it wishes to be able to queue at once (this can only be set once): pipe2(fds, O_NOTIFICATION_PIPE); ioctl(fds[0], IOC_WATCH_QUEUE_SET_SIZE, queue_depth); (2) The application then uses poll() and read() as normal to extract data from the pipe. read() will return multiple notifications if the buffer is big enough, but it will not split a notification across buffers - rather it will return a short read or EMSGSIZE. Notification messages include a length in the header so that the caller can split them up. Each message has a header that describes it: struct watch_notification { __u32 type:24; __u32 subtype:8; __u32 info; }; The type indicates the source (eg. mount tree changes, superblock events, keyring changes, block layer events) and the subtype indicates the event type (eg. mount, unmount; EIO, EDQUOT; link, unlink). The info field indicates a number of things, including the entry length, an ID assigned to a watchpoint contributing to this buffer and type-specific flags. Supplementary data, such as the key ID that generated an event, can be attached in additional slots. The maximum message size is 127 bytes. Messages may not be padded or aligned, so there is no guarantee, for example, that the notification type will be on a 4-byte bounary. Signed-off-by: David Howells <dhowells@redhat.com>
2020-01-15 01:07:11 +08:00
config WATCH_QUEUE
bool "General notification queue"
default n
help
This is a general notification queue for the kernel to pass events to
userspace by splicing them into pipes. It can be used in conjunction
with watches for key/keyring change notifications and device
notifications.
See Documentation/watch_queue.rst
mm/process_vm_access: move config option into init/Kconfig CONFIG_CROSS_MEMORY_ATTACH adds couple syscalls: process_vm_readv and process_vm_writev, it's a kind of IPC for copying data between processes. Currently this option is placed inside "Processor type and features". This patch moves it into "General setup" (where all other arch-independed syscalls and ipc features are placed) and changes prompt string to less cryptic. Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Christopher Yeoh <cyeoh@au1.ibm.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Hugh Dickins <hughd@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-05 07:10:50 +08:00
config CROSS_MEMORY_ATTACH
bool "Enable process_vm_readv/writev syscalls"
depends on MMU
default y
help
Enabling this option adds the system calls process_vm_readv and
process_vm_writev which allow a process with the correct privileges
mm: fix CROSS_MEMORY_ATTACH help text grammar Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-13 04:46:11 +08:00
to directly read from or write to another process' address space.
mm/process_vm_access: move config option into init/Kconfig CONFIG_CROSS_MEMORY_ATTACH adds couple syscalls: process_vm_readv and process_vm_writev, it's a kind of IPC for copying data between processes. Currently this option is placed inside "Processor type and features". This patch moves it into "General setup" (where all other arch-independed syscalls and ipc features are placed) and changes prompt string to less cryptic. Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Christopher Yeoh <cyeoh@au1.ibm.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Hugh Dickins <hughd@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-05 07:10:50 +08:00
See the man page for more details.
fs, kernel: permit disabling the uselib syscall uselib hasn't been used since libc5; glibc does not use it. Support turning it off. When disabled, also omit the load_elf_library implementation from binfmt_elf.c, which only uselib invokes. bloat-o-meter: add/remove: 0/4 grow/shrink: 0/1 up/down: 0/-785 (-785) function old new delta padzero 39 36 -3 uselib_flags 20 - -20 sys_uselib 168 - -168 SyS_uselib 168 - -168 load_elf_library 426 - -426 The new CONFIG_USELIB defaults to `y'. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 05:48:27 +08:00
config USELIB
bool "uselib syscall"
uselib: default depending if libc5 was used uselib hasn't been used since libc5; glibc does not use it. Deprecate uselib a bit more, by making the default y only if libc5 was widely used on the plaform. This makes arm64 kernel built with defconfig slightly smaller bloat-o-meter: add/remove: 0/3 grow/shrink: 0/2 up/down: 0/-1390 (-1390) function old new delta kernel_config_data 18164 18162 -2 uselib_flags 20 - -20 padzero 216 192 -24 sys_uselib 380 - -380 load_elf_library 964 - -964 Signed-off-by: Riku Voipio <riku.voipio@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:58:13 +08:00
def_bool ALPHA || M68K || SPARC || X86_32 || IA32_EMULATION
fs, kernel: permit disabling the uselib syscall uselib hasn't been used since libc5; glibc does not use it. Support turning it off. When disabled, also omit the load_elf_library implementation from binfmt_elf.c, which only uselib invokes. bloat-o-meter: add/remove: 0/4 grow/shrink: 0/1 up/down: 0/-785 (-785) function old new delta padzero 39 36 -3 uselib_flags 20 - -20 sys_uselib 168 - -168 SyS_uselib 168 - -168 load_elf_library 426 - -426 The new CONFIG_USELIB defaults to `y'. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 05:48:27 +08:00
help
This option enables the uselib syscall, a system call used in the
dynamic linker from libc5 and earlier. glibc does not use this
system call. If you intend to run programs built on libc5 or
earlier, you may need to enable this syscall. Current systems
running glibc can safely disable this.
cputime: Gather time/stats accounting config options into a single menu This debloats a bit the general config menu and make these config options easier to find. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:22:07 +08:00
config AUDIT
bool "Auditing support"
depends on NET
help
Enable auditing infrastructure that can be used with another
kernel subsystem, such as SELinux (which requires this for
audit: always enable syscall auditing when supported and audit is enabled To the best of our knowledge, everyone who enables audit at compile time also enables syscall auditing; this patch simplifies the Kconfig menus by removing the option to disable syscall auditing when audit is selected and the target arch supports it. Signed-off-by: Paul Moore <pmoore@redhat.com>
2016-01-13 22:18:55 +08:00
logging of avc messages output). System call auditing is included
on architectures which support it.
cputime: Gather time/stats accounting config options into a single menu This debloats a bit the general config menu and make these config options easier to find. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:22:07 +08:00
audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL Currently AUDITSYSCALL has a long list of architecture depencency: depends on AUDIT && (X86 || PARISC || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT) || ALPHA) The purpose of this patch is to replace it with HAVE_ARCH_AUDITSYSCALL for simplicity. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> (arm) Acked-by: Richard Guy Briggs <rgb@redhat.com> (audit) Acked-by: Matt Turner <mattst88@gmail.com> (alpha) Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Eric Paris <eparis@redhat.com>
2014-02-25 17:16:24 +08:00
config HAVE_ARCH_AUDITSYSCALL
bool
cputime: Gather time/stats accounting config options into a single menu This debloats a bit the general config menu and make these config options easier to find. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:22:07 +08:00
config AUDITSYSCALL
audit: always enable syscall auditing when supported and audit is enabled To the best of our knowledge, everyone who enables audit at compile time also enables syscall auditing; this patch simplifies the Kconfig menus by removing the option to disable syscall auditing when audit is selected and the target arch supports it. Signed-off-by: Paul Moore <pmoore@redhat.com>
2016-01-13 22:18:55 +08:00
def_bool y
audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL Currently AUDITSYSCALL has a long list of architecture depencency: depends on AUDIT && (X86 || PARISC || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT) || ALPHA) The purpose of this patch is to replace it with HAVE_ARCH_AUDITSYSCALL for simplicity. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> (arm) Acked-by: Richard Guy Briggs <rgb@redhat.com> (audit) Acked-by: Matt Turner <mattst88@gmail.com> (alpha) Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Eric Paris <eparis@redhat.com>
2014-02-25 17:16:24 +08:00
depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
cputime: Gather time/stats accounting config options into a single menu This debloats a bit the general config menu and make these config options easier to find. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:22:07 +08:00
select FSNOTIFY
source "kernel/irq/Kconfig"
source "kernel/time/Kconfig"
kconfig: include kernel/Kconfig.preempt from init/Kconfig Almost all architectures include it. Add a ARCH_NO_PREEMPT symbol to disable preempt support for alpha, hexagon, non-coldfire m68k and user mode Linux. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-31 19:39:32 +08:00
source "kernel/Kconfig.preempt"
cputime: Gather time/stats accounting config options into a single menu This debloats a bit the general config menu and make these config options easier to find. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:22:07 +08:00
menu "CPU/Task time and stats accounting"
cputime: Generic on-demand virtual cputime accounting If we want to stop the tick further idle, we need to be able to account the cputime without using the tick. Virtual based cputime accounting solves that problem by hooking into kernel/user boundaries. However implementing CONFIG_VIRT_CPU_ACCOUNTING require low level hooks and involves more overhead. But we already have a generic context tracking subsystem that is required for RCU needs by archs which plan to shut down the tick outside idle. This patch implements a generic virtual based cputime accounting that relies on these generic kernel/user hooks. There are some upsides of doing this: - This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING if context tracking is already built (already necessary for RCU in full tickless mode). - We can rely on the generic context tracking subsystem to dynamically (de)activate the hooks, so that we can switch anytime between virtual and tick based accounting. This way we don't have the overhead of the virtual accounting when the tick is running periodically. And one downside: - There is probably more overhead than a native virtual based cputime accounting. But this relies on hooks that are already set anyway. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-07-25 13:56:04 +08:00
config VIRT_CPU_ACCOUNTING
bool
cputime: Make finegrained irqtime accounting generally available There is no known reason for this option to be unavailable on other archs than x86. They just need to call enable_sched_clock_irqtime() if they have a sufficiently finegrained clock to make it working. Move it to the general option and let the user choose between it and pure tick based or virtual cputime accounting. Note that virtual cputime accounting already performs a finegrained irqtime accounting. CONFIG_IRQ_TIME_ACCOUNTING is a kind of middle ground between tick and virtual based accounting. So CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING are mutually exclusive choices. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:56:31 +08:00
choice
prompt "Cputime accounting"
default TICK_CPU_ACCOUNTING if !PPC64
cputime: Restore CPU_ACCOUNTING config defaults for PPC64 Commit abf917cd91cb ("cputime: Generic on-demand virtual cputime accounting") inadvertantly changed the default CPU_ACCOUNTING config for PPC64. Repair that. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: ppc-dev <linuxppc-dev@lists.ozlabs.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Link: http://lkml.kernel.org/r/20130208141938.f31b7b9e1acac5bbe769ee4c@canb.auug.org.au Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-02-08 11:19:38 +08:00
default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
cputime: Make finegrained irqtime accounting generally available There is no known reason for this option to be unavailable on other archs than x86. They just need to call enable_sched_clock_irqtime() if they have a sufficiently finegrained clock to make it working. Move it to the general option and let the user choose between it and pure tick based or virtual cputime accounting. Note that virtual cputime accounting already performs a finegrained irqtime accounting. CONFIG_IRQ_TIME_ACCOUNTING is a kind of middle ground between tick and virtual based accounting. So CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING are mutually exclusive choices. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:56:31 +08:00
# Kind of a stub config for the pure tick based cputime accounting
config TICK_CPU_ACCOUNTING
bool "Simple tick based cputime accounting"
nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config Turn the full dynticks passive dependency on VIRT_CPU_ACCOUNTING_GEN to an active one. The full dynticks Kconfig is currently hidden behind the full dynticks cputime accounting, which is an awkward and counter-intuitive layout: the user first has to select the dynticks cputime accounting in order to make the full dynticks feature to be visible. We definetly want it the other way around. The usual way to perform this kind of active dependency is use "select" on the depended target. Now we can't use the Kconfig "select" instruction when the target is a "choice". So this patch inspires on how the RCU subsystem Kconfig interact with its dependencies on SMP and PREEMPT: we make sure that cputime accounting can't propose another option than VIRT_CPU_ACCOUNTING_GEN when NO_HZ_FULL is selected by using the right "depends on" instruction for each cputime accounting choices. v2: Keep full dynticks cputime accounting available even without full dynticks, as per Paul McKenney's suggestion. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-26 21:16:31 +08:00
depends on !S390 && !NO_HZ_FULL
cputime: Make finegrained irqtime accounting generally available There is no known reason for this option to be unavailable on other archs than x86. They just need to call enable_sched_clock_irqtime() if they have a sufficiently finegrained clock to make it working. Move it to the general option and let the user choose between it and pure tick based or virtual cputime accounting. Note that virtual cputime accounting already performs a finegrained irqtime accounting. CONFIG_IRQ_TIME_ACCOUNTING is a kind of middle ground between tick and virtual based accounting. So CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING are mutually exclusive choices. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:56:31 +08:00
help
This is the basic tick based cputime accounting that maintains
statistics about user, system and idle time spent on per jiffies
granularity.
If unsure, say Y.
cputime: Generic on-demand virtual cputime accounting If we want to stop the tick further idle, we need to be able to account the cputime without using the tick. Virtual based cputime accounting solves that problem by hooking into kernel/user boundaries. However implementing CONFIG_VIRT_CPU_ACCOUNTING require low level hooks and involves more overhead. But we already have a generic context tracking subsystem that is required for RCU needs by archs which plan to shut down the tick outside idle. This patch implements a generic virtual based cputime accounting that relies on these generic kernel/user hooks. There are some upsides of doing this: - This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING if context tracking is already built (already necessary for RCU in full tickless mode). - We can rely on the generic context tracking subsystem to dynamically (de)activate the hooks, so that we can switch anytime between virtual and tick based accounting. This way we don't have the overhead of the virtual accounting when the tick is running periodically. And one downside: - There is probably more overhead than a native virtual based cputime accounting. But this relies on hooks that are already set anyway. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-07-25 13:56:04 +08:00
config VIRT_CPU_ACCOUNTING_NATIVE
cputime: Generalize CONFIG_VIRT_CPU_ACCOUNTING S390, ia64 and powerpc all define their own version of CONFIG_VIRT_CPU_ACCOUNTING. Generalize the config and its description to a single place to avoid duplication. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-06-16 21:39:34 +08:00
bool "Deterministic task and CPU time accounting"
nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config Turn the full dynticks passive dependency on VIRT_CPU_ACCOUNTING_GEN to an active one. The full dynticks Kconfig is currently hidden behind the full dynticks cputime accounting, which is an awkward and counter-intuitive layout: the user first has to select the dynticks cputime accounting in order to make the full dynticks feature to be visible. We definetly want it the other way around. The usual way to perform this kind of active dependency is use "select" on the depended target. Now we can't use the Kconfig "select" instruction when the target is a "choice". So this patch inspires on how the RCU subsystem Kconfig interact with its dependencies on SMP and PREEMPT: we make sure that cputime accounting can't propose another option than VIRT_CPU_ACCOUNTING_GEN when NO_HZ_FULL is selected by using the right "depends on" instruction for each cputime accounting choices. v2: Keep full dynticks cputime accounting available even without full dynticks, as per Paul McKenney's suggestion. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-26 21:16:31 +08:00
depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
cputime: Generic on-demand virtual cputime accounting If we want to stop the tick further idle, we need to be able to account the cputime without using the tick. Virtual based cputime accounting solves that problem by hooking into kernel/user boundaries. However implementing CONFIG_VIRT_CPU_ACCOUNTING require low level hooks and involves more overhead. But we already have a generic context tracking subsystem that is required for RCU needs by archs which plan to shut down the tick outside idle. This patch implements a generic virtual based cputime accounting that relies on these generic kernel/user hooks. There are some upsides of doing this: - This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING if context tracking is already built (already necessary for RCU in full tickless mode). - We can rely on the generic context tracking subsystem to dynamically (de)activate the hooks, so that we can switch anytime between virtual and tick based accounting. This way we don't have the overhead of the virtual accounting when the tick is running periodically. And one downside: - There is probably more overhead than a native virtual based cputime accounting. But this relies on hooks that are already set anyway. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-07-25 13:56:04 +08:00
select VIRT_CPU_ACCOUNTING
cputime: Generalize CONFIG_VIRT_CPU_ACCOUNTING S390, ia64 and powerpc all define their own version of CONFIG_VIRT_CPU_ACCOUNTING. Generalize the config and its description to a single place to avoid duplication. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-06-16 21:39:34 +08:00
help
Select this option to enable more accurate task and CPU time
accounting. This is done by reading a CPU counter on each
kernel entry and exit and on transitions within the kernel
between system, softirq and hardirq state, so there is a
small performance impact. In the case of s390 or IBM POWER > 5,
this also enables accounting of stolen time on logically-partitioned
systems.
cputime: Generic on-demand virtual cputime accounting If we want to stop the tick further idle, we need to be able to account the cputime without using the tick. Virtual based cputime accounting solves that problem by hooking into kernel/user boundaries. However implementing CONFIG_VIRT_CPU_ACCOUNTING require low level hooks and involves more overhead. But we already have a generic context tracking subsystem that is required for RCU needs by archs which plan to shut down the tick outside idle. This patch implements a generic virtual based cputime accounting that relies on these generic kernel/user hooks. There are some upsides of doing this: - This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING if context tracking is already built (already necessary for RCU in full tickless mode). - We can rely on the generic context tracking subsystem to dynamically (de)activate the hooks, so that we can switch anytime between virtual and tick based accounting. This way we don't have the overhead of the virtual accounting when the tick is running periodically. And one downside: - There is probably more overhead than a native virtual based cputime accounting. But this relies on hooks that are already set anyway. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-07-25 13:56:04 +08:00
config VIRT_CPU_ACCOUNTING_GEN
bool "Full dynticks CPU time accounting"
nohz: Drop generic vtime obsolete dependency on CONFIG_64BIT The CONFIG_64BIT requirement on vtime can finally be removed since we now depend on HAVE_VIRT_CPU_ACCOUNTING_GEN which already takes care of the arch ability to handle nsecs based cputime_t safely. Signed-off-by: Kevin Hilman <khilman@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Arm Linux <linux-arm-kernel@lists.infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2013-09-17 06:28:19 +08:00
depends on HAVE_CONTEXT_TRACKING
vtime: Add HAVE_VIRT_CPU_ACCOUNTING_GEN Kconfig With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit. In order to use that feature, arch code should be audited to ensure there are no races in concurrent read/write of cputime_t. For example, reading/writing 64-bit cputime_t on some 32-bit arches may require multiple accesses for low and high value parts, so proper locking is needed to protect against concurrent accesses. Therefore, add CONFIG_HAVE_VIRT_CPU_ACCOUNTING_GEN which arches can enable after they've been audited for potential races. This option is automatically enabled on 64-bit platforms. Feature requested by Frederic Weisbecker. Signed-off-by: Kevin Hilman <khilman@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Arm Linux <linux-arm-kernel@lists.infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2013-09-17 06:28:21 +08:00
depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
time: Make VIRT_CPU_ACCOUNTING_GEN depend on GENERIC_CLOCKEVENTS Moving the CONTEXT_TRACKING Kconfig option into kernel/time/Kconfig added an implicit dependency on the surrounding GENERIC_CLOCKEVENTS option, but this is not always enabled when it is possible to select VIRT_CPU_ACCOUNTING_GEN: WARNING: unmet direct dependencies detected for CONTEXT_TRACKING Depends on [n]: GENERIC_CLOCKEVENTS [=n] Selected by [y]: - VIRT_CPU_ACCOUNTING_GEN [=y] && <choice> && HAVE_CONTEXT_TRACKING [=y] && HAVE_VIRT_CPU_ACCOUNTING_GEN [=y] Platforms without GENERIC_CLOCKEVENTS are rare enough so that corner case can be just ignored. Make it a dependency for VIRT_CPU_ACCOUNTING_GEN to simplify the configuration. Fixes: a4cffdad7314 ("time: Move CONTEXT_TRACKING to kernel/time/Kconfig") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "Paul E . McKenney" <paulmck@linux.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: https://lkml.kernel.org/r/20190304200202.1163250-1-arnd@arndb.de
2019-03-05 04:01:31 +08:00
depends on GENERIC_CLOCKEVENTS
cputime: Generic on-demand virtual cputime accounting If we want to stop the tick further idle, we need to be able to account the cputime without using the tick. Virtual based cputime accounting solves that problem by hooking into kernel/user boundaries. However implementing CONFIG_VIRT_CPU_ACCOUNTING require low level hooks and involves more overhead. But we already have a generic context tracking subsystem that is required for RCU needs by archs which plan to shut down the tick outside idle. This patch implements a generic virtual based cputime accounting that relies on these generic kernel/user hooks. There are some upsides of doing this: - This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING if context tracking is already built (already necessary for RCU in full tickless mode). - We can rely on the generic context tracking subsystem to dynamically (de)activate the hooks, so that we can switch anytime between virtual and tick based accounting. This way we don't have the overhead of the virtual accounting when the tick is running periodically. And one downside: - There is probably more overhead than a native virtual based cputime accounting. But this relies on hooks that are already set anyway. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-07-25 13:56:04 +08:00
select VIRT_CPU_ACCOUNTING
select CONTEXT_TRACKING
help
Select this option to enable task and CPU time accounting on full
dynticks systems. This accounting is implemented by watching every
kernel-user boundaries using the context tracking subsystem.
The accounting is thus performed at the expense of some significant
overhead.
For now this is only useful if you are working on the full
dynticks subsystem development.
If unsure, say N.
sched/cputime: Replace VTIME_GEN irq time code with IRQ_TIME_ACCOUNTING code The CONFIG_VIRT_CPU_ACCOUNTING_GEN irq time tracking code does not appear to currently work right. On CPUs without nohz_full=, only tick based irq time sampling is done, which breaks down when dealing with a nohz_idle CPU. On firewalls and similar systems, no ticks may happen on a CPU for a while, and the irq time spent may never get accounted properly. This can cause issues with capacity planning and power saving, which use the CPU statistics as inputs in decision making. Remove the VTIME_GEN vtime irq time code, and replace it with the IRQ_TIME_ACCOUNTING code, when selected as a config option by the user. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1468421405-20056-3-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-13 22:50:02 +08:00
endchoice
cputime: Make finegrained irqtime accounting generally available There is no known reason for this option to be unavailable on other archs than x86. They just need to call enable_sched_clock_irqtime() if they have a sufficiently finegrained clock to make it working. Move it to the general option and let the user choose between it and pure tick based or virtual cputime accounting. Note that virtual cputime accounting already performs a finegrained irqtime accounting. CONFIG_IRQ_TIME_ACCOUNTING is a kind of middle ground between tick and virtual based accounting. So CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING are mutually exclusive choices. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:56:31 +08:00
config IRQ_TIME_ACCOUNTING
bool "Fine granularity task level IRQ time accounting"
sched/cputime: Replace VTIME_GEN irq time code with IRQ_TIME_ACCOUNTING code The CONFIG_VIRT_CPU_ACCOUNTING_GEN irq time tracking code does not appear to currently work right. On CPUs without nohz_full=, only tick based irq time sampling is done, which breaks down when dealing with a nohz_idle CPU. On firewalls and similar systems, no ticks may happen on a CPU for a while, and the irq time spent may never get accounted properly. This can cause issues with capacity planning and power saving, which use the CPU statistics as inputs in decision making. Remove the VTIME_GEN vtime irq time code, and replace it with the IRQ_TIME_ACCOUNTING code, when selected as a config option by the user. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1468421405-20056-3-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-13 22:50:02 +08:00
depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
cputime: Make finegrained irqtime accounting generally available There is no known reason for this option to be unavailable on other archs than x86. They just need to call enable_sched_clock_irqtime() if they have a sufficiently finegrained clock to make it working. Move it to the general option and let the user choose between it and pure tick based or virtual cputime accounting. Note that virtual cputime accounting already performs a finegrained irqtime accounting. CONFIG_IRQ_TIME_ACCOUNTING is a kind of middle ground between tick and virtual based accounting. So CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING are mutually exclusive choices. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:56:31 +08:00
help
Select this option to enable fine granularity task irq time
accounting. This is done by reading a timestamp on each
transitions between softirq and hardirq state, so there can be a
small performance impact.
If in doubt, say N here.
sched/pelt: Fix warning and clean up IRQ PELT config Create a config for enabling irq load tracking in the scheduler. irq load tracking is useful only when irq or paravirtual time is accounted but it's only possible with SMP for now. Also use __maybe_unused to remove the compilation warning in update_rq_clock_task() that has been introduced by: 2e62c4743adc ("sched/fair: Remove #ifdefs from scale_rt_capacity()") Suggested-by: Ingo Molnar <mingo@redhat.com> Reported-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Reported-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: dou_liyang@163.com Fixes: 2e62c4743adc ("sched/fair: Remove #ifdefs from scale_rt_capacity()") Link: http://lkml.kernel.org/r/1537867062-27285-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-25 17:17:42 +08:00
config HAVE_SCHED_AVG_IRQ
def_bool y
depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
depends on SMP
sched/pelt: Add support to track thermal pressure Extrapolating on the existing framework to track rt/dl utilization using pelt signals, add a similar mechanism to track thermal pressure. The difference here from rt/dl utilization tracking is that, instead of tracking time spent by a CPU running a RT/DL task through util_avg, the average thermal pressure is tracked through load_avg. This is because thermal pressure signal is weighted time "delta" capacity unlike util_avg which is binary. "delta capacity" here means delta between the actual capacity of a CPU and the decreased capacity a CPU due to a thermal event. In order to track average thermal pressure, a new sched_avg variable avg_thermal is introduced. Function update_thermal_load_avg can be called to do the periodic bookkeeping (accumulate, decay and average) of the thermal pressure. Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20200222005213.3873-2-thara.gopinath@linaro.org
2020-02-22 08:52:05 +08:00
config SCHED_THERMAL_PRESSURE
bool "Enable periodic averaging of thermal pressure"
depends on SMP
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config BSD_PROCESS_ACCT
bool "BSD Process Accounting"
kernel: conditionally support non-root users, groups and capabilities There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-16 07:16:41 +08:00
depends on MULTIUSER
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
help
If you say Y here, a user level program will be able to instruct the
kernel (via a special system call) to write process accounting
information to a file: whenever a process exits, information about
that process will be appended to the file by the kernel. The
information includes things such as creation time, owning user,
command name, memory usage, controlling terminal etc. (the complete
list is in the struct acct in <file:include/linux/acct.h>). It is
up to the user level program to do useful things with this
information. This is generally a good idea, so say Y.
config BSD_PROCESS_ACCT_V3
bool "BSD Process Accounting version 3 file format"
depends on BSD_PROCESS_ACCT
default n
help
If you say Y here, the process accounting information is written
in a new file format that also logs the process IDs of each
init/Kconfig: fix its typos Correct typos of "it's" to "its. Link: http://lkml.kernel.org/r/0ac627b6-5527-55f4-0489-1631aa34fc11@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 12:58:34 +08:00
process and its parent. Note that this file format is incompatible
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
with previous v0/v1/v2 file formats, so you will need updated tools
for processing it. A preliminary version of these tools is available
init: fix URL of "The GNU Accounting Utilities" Following patch corrects URL of "The GNU Accounting Utilities" in init/Kconfig. Noticed by: Bart Van Assche" <bart.vanassche@gmail.com> Signed-off-by: S.Çağlar Onur <caglar@pardus.org.tr> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-06-18 16:45:13 +08:00
at <http://www.gnu.org/software/acct/>.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
[PATCH] per-task-delay-accounting: taskstats interface Create a "taskstats" interface based on generic netlink (NETLINK_GENERIC family), for getting statistics of tasks and thread groups during their lifetime and when they exit. The interface is intended for use by multiple accounting packages though it is being created in the context of delay accounting. This patch creates the interface without populating the fields of the data that is sent to the user in response to a command or upon the exit of a task. Each accounting package interested in using taskstats has to provide an additional patch to add its stats to the common structure. [akpm@osdl.org: cleanups, Kconfig fix] Signed-off-by: Shailabh Nagar <nagar@us.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 15:24:40 +08:00
config TASKSTATS
init: remove depends on CONFIG_EXPERIMENTAL The CONFIG_EXPERIMENTAL config item has not carried much meaning for a while now and is almost always enabled by default. As agreed during the Linux kernel summit, remove it from any "depends on" lines in Kconfigs. CC: "Eric W. Biederman" <ebiederm@xmission.com> CC: Serge Hallyn <serge.hallyn@canonical.com> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2012-10-03 02:19:29 +08:00
bool "Export task/process statistics through netlink"
[PATCH] per-task-delay-accounting: taskstats interface Create a "taskstats" interface based on generic netlink (NETLINK_GENERIC family), for getting statistics of tasks and thread groups during their lifetime and when they exit. The interface is intended for use by multiple accounting packages though it is being created in the context of delay accounting. This patch creates the interface without populating the fields of the data that is sent to the user in response to a command or upon the exit of a task. Each accounting package interested in using taskstats has to provide an additional patch to add its stats to the common structure. [akpm@osdl.org: cleanups, Kconfig fix] Signed-off-by: Shailabh Nagar <nagar@us.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 15:24:40 +08:00
depends on NET
kernel: conditionally support non-root users, groups and capabilities There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-16 07:16:41 +08:00
depends on MULTIUSER
[PATCH] per-task-delay-accounting: taskstats interface Create a "taskstats" interface based on generic netlink (NETLINK_GENERIC family), for getting statistics of tasks and thread groups during their lifetime and when they exit. The interface is intended for use by multiple accounting packages though it is being created in the context of delay accounting. This patch creates the interface without populating the fields of the data that is sent to the user in response to a command or upon the exit of a task. Each accounting package interested in using taskstats has to provide an additional patch to add its stats to the common structure. [akpm@osdl.org: cleanups, Kconfig fix] Signed-off-by: Shailabh Nagar <nagar@us.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 15:24:40 +08:00
default n
help
Export selected statistics for tasks/processes through the
generic netlink interface. Unlike BSD process accounting, the
statistics are available during the lifetime of tasks/processes as
responses to commands. Like BSD accounting, they are sent to user
space on task exit.
Say N if unsure.
[PATCH] per-task-delay-accounting: setup Initialization code related to collection of per-task "delay" statistics which measure how long it had to wait for cpu, sync block io, swapping etc. The collection of statistics and the interface are in other patches. This patch sets up the data structures and allows the statistics collection to be disabled through a kernel boot parameter. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 15:24:36 +08:00
config TASK_DELAY_ACCT
init: remove depends on CONFIG_EXPERIMENTAL The CONFIG_EXPERIMENTAL config item has not carried much meaning for a while now and is almost always enabled by default. As agreed during the Linux kernel summit, remove it from any "depends on" lines in Kconfigs. CC: "Eric W. Biederman" <ebiederm@xmission.com> CC: Serge Hallyn <serge.hallyn@canonical.com> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2012-10-03 02:19:29 +08:00
bool "Enable per-task delay accounting"
[PATCH] per-task-delay-accounting: delay accounting usage of taskstats interface Usage of taskstats interface by delay accounting. Signed-off-by: Shailabh Nagar <nagar@us.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 15:24:41 +08:00
depends on TASKSTATS
sched/stat: Simplify the sched_info accounting dependency Both CONFIG_SCHEDSTATS=y and CONFIG_TASK_DELAY_ACCT=y track task sched_info, which results in ugly #if clauses. Simplify the code by introducing a synthethic CONFIG_SCHED_INFO switch, selected by both. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: a.p.zijlstra@chello.nl Cc: ricklind@us.ibm.com Link: http://lkml.kernel.org/r/8d19eef800811a94b0f91bcbeb27430a884d7433.1435255405.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-26 02:23:37 +08:00
select SCHED_INFO
[PATCH] per-task-delay-accounting: setup Initialization code related to collection of per-task "delay" statistics which measure how long it had to wait for cpu, sync block io, swapping etc. The collection of statistics and the interface are in other patches. This patch sets up the data structures and allows the statistics collection to be disabled through a kernel boot parameter. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 15:24:36 +08:00
help
Collect information on time spent by a task waiting for system
resources like cpu, synchronous block I/O completion and swapping
in pages. Such statistics can help in setting a task's priorities
relative to other tasks for cpu, io, rss limits etc.
Say N if unsure.
[PATCH] Move TASK_XACCT, TASK_IO_ACCOUNTING up in menus Since they depends on TASKSTATS, it would be nice to move them closer to another options depending on TASKSTATS. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-10 17:46:44 +08:00
config TASK_XACCT
init: remove depends on CONFIG_EXPERIMENTAL The CONFIG_EXPERIMENTAL config item has not carried much meaning for a while now and is almost always enabled by default. As agreed during the Linux kernel summit, remove it from any "depends on" lines in Kconfigs. CC: "Eric W. Biederman" <ebiederm@xmission.com> CC: Serge Hallyn <serge.hallyn@canonical.com> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2012-10-03 02:19:29 +08:00
bool "Enable extended accounting over taskstats"
[PATCH] Move TASK_XACCT, TASK_IO_ACCOUNTING up in menus Since they depends on TASKSTATS, it would be nice to move them closer to another options depending on TASKSTATS. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-10 17:46:44 +08:00
depends on TASKSTATS
help
Collect extended task accounting data and send the data
to userland for processing over the taskstats interface.
Say N if unsure.
config TASK_IO_ACCOUNTING
init: remove depends on CONFIG_EXPERIMENTAL The CONFIG_EXPERIMENTAL config item has not carried much meaning for a while now and is almost always enabled by default. As agreed during the Linux kernel summit, remove it from any "depends on" lines in Kconfigs. CC: "Eric W. Biederman" <ebiederm@xmission.com> CC: Serge Hallyn <serge.hallyn@canonical.com> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2012-10-03 02:19:29 +08:00
bool "Enable per-task storage I/O accounting"
[PATCH] Move TASK_XACCT, TASK_IO_ACCOUNTING up in menus Since they depends on TASKSTATS, it would be nice to move them closer to another options depending on TASKSTATS. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-10 17:46:44 +08:00
depends on TASK_XACCT
help
Collect information on the number of bytes of storage I/O which this
task has caused.
Say N if unsure.
psi: pressure stall information for CPU, memory, and IO When systems are overcommitted and resources become contended, it's hard to tell exactly the impact this has on workload productivity, or how close the system is to lockups and OOM kills. In particular, when machines work multiple jobs concurrently, the impact of overcommit in terms of latency and throughput on the individual job can be enormous. In order to maximize hardware utilization without sacrificing individual job health or risk complete machine lockups, this patch implements a way to quantify resource pressure in the system. A kernel built with CONFIG_PSI=y creates files in /proc/pressure/ that expose the percentage of time the system is stalled on CPU, memory, or IO, respectively. Stall states are aggregate versions of the per-task delay accounting delays: cpu: some tasks are runnable but not executing on a CPU memory: tasks are reclaiming, or waiting for swapin or thrashing cache io: tasks are waiting for io completions These percentages of walltime can be thought of as pressure percentages, and they give a general sense of system health and productivity loss incurred by resource overcommit. They can also indicate when the system is approaching lockup scenarios and OOMs. To do this, psi keeps track of the task states associated with each CPU and samples the time they spend in stall states. Every 2 seconds, the samples are averaged across CPUs - weighted by the CPUs' non-idle time to eliminate artifacts from unused CPUs - and translated into percentages of walltime. A running average of those percentages is maintained over 10s, 1m, and 5m periods (similar to the loadaverage). [hannes@cmpxchg.org: doc fixlet, per Randy] Link: http://lkml.kernel.org/r/20180828205625.GA14030@cmpxchg.org [hannes@cmpxchg.org: code optimization] Link: http://lkml.kernel.org/r/20180907175015.GA8479@cmpxchg.org [hannes@cmpxchg.org: rename psi_clock() to psi_update_work(), per Peter] Link: http://lkml.kernel.org/r/20180907145404.GB11088@cmpxchg.org [hannes@cmpxchg.org: fix build] Link: http://lkml.kernel.org/r/20180913014222.GA2370@cmpxchg.org Link: http://lkml.kernel.org/r/20180828172258.3185-9-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Drake <drake@endlessm.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-27 06:06:27 +08:00
config PSI
bool "Pressure stall information tracking"
help
Collect metrics that indicate how overcommitted the CPU, memory,
and IO capacity are in the system.
If you say Y here, the kernel will create /proc/pressure/ with the
pressure statistics files cpu, memory, and io. These will indicate
the share of walltime in which some or all tasks in the system are
delayed due to contention of the respective resource.
psi: cgroup support On a system that executes multiple cgrouped jobs and independent workloads, we don't just care about the health of the overall system, but also that of individual jobs, so that we can ensure individual job health, fairness between jobs, or prioritize some jobs over others. This patch implements pressure stall tracking for cgroups. In kernels with CONFIG_PSI=y, cgroup2 groups will have cpu.pressure, memory.pressure, and io.pressure files that track aggregate pressure stall times for only the tasks inside the cgroup. Link: http://lkml.kernel.org/r/20180828172258.3185-10-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Drake <drake@endlessm.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-27 06:06:31 +08:00
In kernels with cgroup support, cgroups (cgroup2 only) will
have cpu.pressure, memory.pressure, and io.pressure files,
which aggregate pressure stalls for the grouped tasks only.
docs: accounting: convert to ReST Rename the accounting documentation files to ReST, add an index for them and adjust in order to produce a nice html output via the Sphinx build system. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-04-17 16:46:08 +08:00
For more details see Documentation/accounting/psi.rst.
psi: pressure stall information for CPU, memory, and IO When systems are overcommitted and resources become contended, it's hard to tell exactly the impact this has on workload productivity, or how close the system is to lockups and OOM kills. In particular, when machines work multiple jobs concurrently, the impact of overcommit in terms of latency and throughput on the individual job can be enormous. In order to maximize hardware utilization without sacrificing individual job health or risk complete machine lockups, this patch implements a way to quantify resource pressure in the system. A kernel built with CONFIG_PSI=y creates files in /proc/pressure/ that expose the percentage of time the system is stalled on CPU, memory, or IO, respectively. Stall states are aggregate versions of the per-task delay accounting delays: cpu: some tasks are runnable but not executing on a CPU memory: tasks are reclaiming, or waiting for swapin or thrashing cache io: tasks are waiting for io completions These percentages of walltime can be thought of as pressure percentages, and they give a general sense of system health and productivity loss incurred by resource overcommit. They can also indicate when the system is approaching lockup scenarios and OOMs. To do this, psi keeps track of the task states associated with each CPU and samples the time they spend in stall states. Every 2 seconds, the samples are averaged across CPUs - weighted by the CPUs' non-idle time to eliminate artifacts from unused CPUs - and translated into percentages of walltime. A running average of those percentages is maintained over 10s, 1m, and 5m periods (similar to the loadaverage). [hannes@cmpxchg.org: doc fixlet, per Randy] Link: http://lkml.kernel.org/r/20180828205625.GA14030@cmpxchg.org [hannes@cmpxchg.org: code optimization] Link: http://lkml.kernel.org/r/20180907175015.GA8479@cmpxchg.org [hannes@cmpxchg.org: rename psi_clock() to psi_update_work(), per Peter] Link: http://lkml.kernel.org/r/20180907145404.GB11088@cmpxchg.org [hannes@cmpxchg.org: fix build] Link: http://lkml.kernel.org/r/20180913014222.GA2370@cmpxchg.org Link: http://lkml.kernel.org/r/20180828172258.3185-9-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Drake <drake@endlessm.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-27 06:06:27 +08:00
Say N if unsure.
psi: make disabling/enabling easier for vendor kernels Mel Gorman reports a hackbench regression with psi that would prohibit shipping the suse kernel with it default-enabled, but he'd still like users to be able to opt in at little to no cost to others. With the current combination of CONFIG_PSI and the psi_disabled bool set from the commandline, this is a challenge. Do the following things to make it easier: 1. Add a config option CONFIG_PSI_DEFAULT_DISABLED that allows distros to enable CONFIG_PSI in their kernel but leave the feature disabled unless a user requests it at boot-time. To avoid double negatives, rename psi_disabled= to psi=. 2. Make psi_disabled a static branch to eliminate any branch costs when the feature is disabled. In terms of numbers before and after this patch, Mel says: : The following is a comparision using CONFIG_PSI=n as a baseline against : your patch and a vanilla kernel : : 4.20.0-rc4 4.20.0-rc4 4.20.0-rc4 : kconfigdisable-v1r1 vanilla psidisable-v1r1 : Amean 1 1.3100 ( 0.00%) 1.3923 ( -6.28%) 1.3427 ( -2.49%) : Amean 3 3.8860 ( 0.00%) 4.1230 * -6.10%* 3.8860 ( -0.00%) : Amean 5 6.8847 ( 0.00%) 8.0390 * -16.77%* 6.7727 ( 1.63%) : Amean 7 9.9310 ( 0.00%) 10.8367 * -9.12%* 9.9910 ( -0.60%) : Amean 12 16.6577 ( 0.00%) 18.2363 * -9.48%* 17.1083 ( -2.71%) : Amean 18 26.5133 ( 0.00%) 27.8833 * -5.17%* 25.7663 ( 2.82%) : Amean 24 34.3003 ( 0.00%) 34.6830 ( -1.12%) 32.0450 ( 6.58%) : Amean 30 40.0063 ( 0.00%) 40.5800 ( -1.43%) 41.5087 ( -3.76%) : Amean 32 40.1407 ( 0.00%) 41.2273 ( -2.71%) 39.9417 ( 0.50%) : : It's showing that the vanilla kernel takes a hit (as the bisection : indicated it would) and that disabling PSI by default is reasonably : close in terms of performance for this particular workload on this : particular machine so; Link: http://lkml.kernel.org/r/20181127165329.GA29728@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-01 06:09:58 +08:00
config PSI_DEFAULT_DISABLED
bool "Require boot parameter to enable pressure stall information tracking"
default n
depends on PSI
help
If set, pressure stall information tracking will be disabled
psi: fix reference to kernel commandline enable The kernel commandline parameter named in CONFIG_PSI_DEFAULT_DISABLED help text contradicts the documentation in kernel-parameters.txt, and the code. Fix that. Link: http://lkml.kernel.org/r/20181203213416.GA12627@cmpxchg.org Fixes: e0c274472d ("psi: make disabling/enabling easier for vendor kernels") Signed-off-by: Baruch Siach <baruch@tkos.co.il> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-15 06:17:03 +08:00
per default but can be enabled through passing psi=1 on the
kernel commandline during boot.
psi: make disabling/enabling easier for vendor kernels Mel Gorman reports a hackbench regression with psi that would prohibit shipping the suse kernel with it default-enabled, but he'd still like users to be able to opt in at little to no cost to others. With the current combination of CONFIG_PSI and the psi_disabled bool set from the commandline, this is a challenge. Do the following things to make it easier: 1. Add a config option CONFIG_PSI_DEFAULT_DISABLED that allows distros to enable CONFIG_PSI in their kernel but leave the feature disabled unless a user requests it at boot-time. To avoid double negatives, rename psi_disabled= to psi=. 2. Make psi_disabled a static branch to eliminate any branch costs when the feature is disabled. In terms of numbers before and after this patch, Mel says: : The following is a comparision using CONFIG_PSI=n as a baseline against : your patch and a vanilla kernel : : 4.20.0-rc4 4.20.0-rc4 4.20.0-rc4 : kconfigdisable-v1r1 vanilla psidisable-v1r1 : Amean 1 1.3100 ( 0.00%) 1.3923 ( -6.28%) 1.3427 ( -2.49%) : Amean 3 3.8860 ( 0.00%) 4.1230 * -6.10%* 3.8860 ( -0.00%) : Amean 5 6.8847 ( 0.00%) 8.0390 * -16.77%* 6.7727 ( 1.63%) : Amean 7 9.9310 ( 0.00%) 10.8367 * -9.12%* 9.9910 ( -0.60%) : Amean 12 16.6577 ( 0.00%) 18.2363 * -9.48%* 17.1083 ( -2.71%) : Amean 18 26.5133 ( 0.00%) 27.8833 * -5.17%* 25.7663 ( 2.82%) : Amean 24 34.3003 ( 0.00%) 34.6830 ( -1.12%) 32.0450 ( 6.58%) : Amean 30 40.0063 ( 0.00%) 40.5800 ( -1.43%) 41.5087 ( -3.76%) : Amean 32 40.1407 ( 0.00%) 41.2273 ( -2.71%) 39.9417 ( 0.50%) : : It's showing that the vanilla kernel takes a hit (as the bisection : indicated it would) and that disabling PSI by default is reasonably : close in terms of performance for this particular workload on this : particular machine so; Link: http://lkml.kernel.org/r/20181127165329.GA29728@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-01 06:09:58 +08:00
psi: clarify the Kconfig text for the default-disable option The current help text caused some confusion in online forums about whether or not to default-enable or default-disable psi in vendor kernels. This is because it doesn't communicate the reason for why we made this setting configurable in the first place: that the overhead is non-zero in an artificial scheduler stress test. Since this isn't representative of real workloads, and the effect was not measurable in scheduler-heavy real world applications such as the webservers and memcache installations at Facebook, it's fair to point out that this is a pretty cautious option to select. Link: http://lkml.kernel.org/r/20190129233617.16767-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-02 06:21:15 +08:00
This feature adds some code to the task wakeup and sleep
paths of the scheduler. The overhead is too low to affect
common scheduling-intense workloads in practice (such as
webservers, memcache), but it does show up in artificial
scheduler stress tests, such as hackbench.
If you are paranoid and not sure what the kernel will be
used for, say Y.
Say N if unsure.
cputime: Gather time/stats accounting config options into a single menu This debloats a bit the general config menu and make these config options easier to find. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2012-09-09 20:22:07 +08:00
endmenu # "CPU/Task time and stats accounting"
genirq: Provide Kconfig The generic irq Kconfig options are copied around all archs. Provide a generic Kconfig file which can be included. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121843.217333624@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-27 20:45:59 +08:00
sched/isolation: Split out new CONFIG_CPU_ISOLATION=y config from CONFIG_NO_HZ_FULL Split the housekeeping config from CONFIG_NO_HZ_FULL. This way we finally separate the isolation code from NOHZ. Although a dependency to CONFIG_NO_HZ_FULL remains for now, while the housekeeping code still deals with NOHZ internals. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-8-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27 10:42:34 +08:00
config CPU_ISOLATION
bool "CPU isolation"
sched/isolation: Make CONFIG_CPU_ISOLATION=y depend on SMP or COMPILE_TEST On uniprocessor systems, critical and non-critical tasks cannot be isolated, as there is only a single CPU core. Hence enabling CPU isolation by default on such systems does not make much sense. Instead of changing the default for !SMP, fix this by making the feature depend on SMP, with an override for compile-testing. Note that its sole selector (NO_HZ_FULL) already depends on SMP. This decreases kernel size for a default uniprocessor kernel by ca. 1 KiB. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Nicolas Pitre <nico@linaro.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 2c43838c99d9d23f ("sched/isolation: Enable CONFIG_CPU_ISOLATION=y by default") Link: http://lkml.kernel.org/r/1514891590-20782-1-git-send-email-geert@linux-m68k.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-02 19:13:10 +08:00
depends on SMP || COMPILE_TEST
sched/isolation: Enable CONFIG_CPU_ISOLATION=y by default The "isolcpus=" boot parameter support was always built-in before we moved the related code under CONFIG_CPU_ISOLATION. Having it disabled by default is very confusing for people accustomed to use this parameter. So enable it by dafault to keep the previous behaviour but keep it optable for those who want to tinify their kernels. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <kernellwp@gmail.com> Cc: kernel test robot <xiaolong.ye@intel.com> Link: http://lkml.kernel.org/r/1513275507-29200-3-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 02:18:26 +08:00
default y
sched/isolation: Split out new CONFIG_CPU_ISOLATION=y config from CONFIG_NO_HZ_FULL Split the housekeeping config from CONFIG_NO_HZ_FULL. This way we finally separate the isolation code from NOHZ. Although a dependency to CONFIG_NO_HZ_FULL remains for now, while the housekeeping code still deals with NOHZ internals. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-8-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27 10:42:34 +08:00
help
Make sure that CPUs running critical tasks are not disturbed by
any source of "noise" such as unbound workqueues, timers, kthreads...
sched/isolation: Enable CONFIG_CPU_ISOLATION=y by default The "isolcpus=" boot parameter support was always built-in before we moved the related code under CONFIG_CPU_ISOLATION. Having it disabled by default is very confusing for people accustomed to use this parameter. So enable it by dafault to keep the previous behaviour but keep it optable for those who want to tinify their kernels. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <kernellwp@gmail.com> Cc: kernel test robot <xiaolong.ye@intel.com> Link: http://lkml.kernel.org/r/1513275507-29200-3-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15 02:18:26 +08:00
Unbound jobs get offloaded to housekeeping CPUs. This is driven by
the "isolcpus=" boot parameter.
Say Y if unsure.
sched/isolation: Split out new CONFIG_CPU_ISOLATION=y config from CONFIG_NO_HZ_FULL Split the housekeeping config from CONFIG_NO_HZ_FULL. This way we finally separate the isolation code from NOHZ. Although a dependency to CONFIG_NO_HZ_FULL remains for now, while the housekeeping code still deals with NOHZ internals. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-8-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27 10:42:34 +08:00
rcu: Move RCU non-debug Kconfig options to kernel/rcu RCU's Kconfig options are scattered, and there are enough of them that it would be good for them to be more centralized. This commit therefore extracts RCU's Kconfig options from init/Kconfig into a new kernel/rcu/Kconfig file. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-05-17 23:43:40 +08:00
source "kernel/rcu/Kconfig"
rcu: move Kconfig menu Move RCU Kconfig options from top-level menu to an "RCU Subsystem" menu under the "General Setup" menu. Signed-off-by: Mike Travis <travis@sgi.com> Tested-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-16 04:28:29 +08:00
kernel: build bin2c based on config option CONFIG_BUILD_BIN2C currently bin2c builds only if CONFIG_IKCONFIG=y. But bin2c will now be used by kexec too. So make it compilation dependent on CONFIG_BUILD_BIN2C and this config option can be selected by CONFIG_KEXEC and CONFIG_IKCONFIG. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-09 05:25:41 +08:00
config BUILD_BIN2C
bool
default n
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config IKCONFIG
[PATCH] allow /proc/config.gz to be built as a module The driver for /proc/config.gz consumes rather a lot of memory and it is in fact possible to build it as a module. In some ways this is a bit risky, because the .config which is used for compiling kernel/configs.c isn't necessarily the same as the .config which was used to build vmlinux. But OTOH the potential memory savings are decent, and it'd be fairly dumb to build your configs.o with a different .config. Signed-off-by: Andrew Morton <akpm@google.com> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 14:27:25 +08:00
tristate "Kernel .config support"
treewide: replace '---help---' in Kconfig files with 'help' Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 00:50:22 +08:00
help
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
This option enables the complete Linux kernel ".config" file
contents to be saved in the kernel. It provides documentation
of which kernel options are used in a running kernel or in an
on-disk kernel. This information can be extracted from the kernel
image file with the script scripts/extract-ikconfig and used as
input to rebuild the current kernel or to build another kernel.
It can also be extracted from a running kernel by reading
/proc/config.gz if enabled (below).
config IKCONFIG_PROC
bool "Enable access to .config through /proc/config.gz"
depends on IKCONFIG && PROC_FS
treewide: replace '---help---' in Kconfig files with 'help' Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 00:50:22 +08:00
help
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
This option enables access to the kernel configuration file
through /proc/config.gz.
kheaders: Move from proc to sysfs The kheaders archive consisting of the kernel headers used for compiling bpf programs is in /proc. However there is concern that moving it here will make it permanent. Let us move it to /sys/kernel as discussed [1]. [1] https://lore.kernel.org/patchwork/patch/1067310/#1265969 Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-16 05:35:51 +08:00
config IKHEADERS
tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
depends on SYSFS
help
This option enables access to the in-kernel headers that are generated during
the build process. These can be used to build eBPF tracing programs,
or similar programs. If you build the headers as a module, a module called
kheaders.ko is built which can be loaded on-demand to get access to headers.
Provide in-kernel headers to make extending kernel easier Introduce in-kernel headers which are made available as an archive through proc (/proc/kheaders.tar.xz file). This archive makes it possible to run eBPF and other tracing programs that need to extend the kernel for tracing purposes without any dependency on the file system having headers. A github PR is sent for the corresponding BCC patch at: https://github.com/iovisor/bcc/pull/2312 On Android and embedded systems, it is common to switch kernels but not have kernel headers available on the file system. Further once a different kernel is booted, any headers stored on the file system will no longer be useful. This is an issue even well known to distros. By storing the headers as a compressed archive within the kernel, we can avoid these issues that have been a hindrance for a long time. The best way to use this feature is by building it in. Several users have a need for this, when they switch debug kernels, they do not want to update the filesystem or worry about it where to store the headers on it. However, the feature is also buildable as a module in case the user desires it not being part of the kernel image. This makes it possible to load and unload the headers from memory on demand. A tracing program can load the module, do its operations, and then unload the module to save kernel memory. The total memory needed is 3.3MB. By having the archive available at a fixed location independent of filesystem dependencies and conventions, all debugging tools can directly refer to the fixed location for the archive, without concerning with where the headers on a typical filesystem which significantly simplifies tooling that needs kernel headers. The code to read the headers is based on /proc/config.gz code and uses the same technique to embed the headers. Other approaches were discussed such as having an in-memory mountable filesystem, but that has drawbacks such as requiring an in-kernel xz decompressor which we don't have today, and requiring usage of 42 MB of kernel memory to host the decompressed headers at anytime. Also this approach is simpler than such approaches. Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-27 03:04:29 +08:00
Move LOG_BUF_SHIFT to a more sensible place Several people have observed that perhaps LOG_BUF_SHIFT should be in a more obvious place than under DEBUG_KERNEL. Under some circumstances (such as the PARISC architecture), DEBUG_KERNEL can increase kernel size, which is an undesirable trade off for something as trivial as increasing the kernel log buffer size. Instead, move LOG_BUF_SHIFT into "General Setup", so that people are more likely to be able to change it such a circumstance that the default buffer size is insufficient. Signed-off-by: Alistair John Strachan <s0348365@sms.ed.ac.uk> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 15:31:15 +08:00
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
printk: Increase maximum CONFIG_LOG_BUF_SHIFT from 21 to 25 So I tried to some kernel debugging that produced a ton of kernel messages on a big box, and wanted to save them all: but CONFIG_LOG_BUF_SHIFT maxes out at 21 (2 MB). Increase it to 25 (32 MB). This does not affect any existing config or defaults. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-01 16:19:11 +08:00
range 12 25
let LOG_BUF_SHIFT default to 17 16 kB is often no longer enough for a normal boot of an UP system. And even less when people e.g. use suspend. 17 seems to be a more reasonable default for current kernels on current hardware (it's just the default, anyone who is memory limited can still lower it). Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 15:58:58 +08:00
default 17
init/Kconfig: Hide printk log config if CONFIG_PRINTK=n The buffers sized by CONFIG_LOG_BUF_SHIFT and CONFIG_LOG_CPU_MAX_BUF_SHIFT do not exist if CONFIG_PRINTK=n, so don't ask about their size at all. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: stable <stable@vger.kernel.org>
2014-10-04 07:00:54 +08:00
depends on PRINTK
Move LOG_BUF_SHIFT to a more sensible place Several people have observed that perhaps LOG_BUF_SHIFT should be in a more obvious place than under DEBUG_KERNEL. Under some circumstances (such as the PARISC architecture), DEBUG_KERNEL can increase kernel size, which is an undesirable trade off for something as trivial as increasing the kernel log buffer size. Instead, move LOG_BUF_SHIFT into "General Setup", so that people are more likely to be able to change it such a circumstance that the default buffer size is insufficient. Signed-off-by: Alistair John Strachan <s0348365@sms.ed.ac.uk> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 15:31:15 +08:00
help
printk: allow increasing the ring buffer depending on the number of CPUs The default size of the ring buffer is too small for machines with a large amount of CPUs under heavy load. What ends up happening when debugging is the ring buffer overlaps and chews up old messages making debugging impossible unless the size is passed as a kernel parameter. An idle system upon boot up will on average spew out only about one or two extra lines but where this really matters is on heavy load and that will vary widely depending on the system and environment. There are mechanisms to help increase the kernel ring buffer for tracing through debugfs, and those interfaces even allow growing the kernel ring buffer per CPU. We also have a static value which can be passed upon boot. Relying on debugfs however is not ideal for production, and relying on the value passed upon bootup is can only used *after* an issue has creeped up. Instead of being reactive this adds a proactive measure which lets you scale the amount of contributions you'd expect to the kernel ring buffer under load by each CPU in the worst case scenario. We use num_possible_cpus() to avoid complexities which could be introduced by dynamically changing the ring buffer size at run time, num_possible_cpus() lets us use the upper limit on possible number of CPUs therefore avoiding having to deal with hotplugging CPUs on and off. This introduces the kernel configuration option LOG_CPU_MAX_BUF_SHIFT which is used to specify the maximum amount of contributions to the kernel ring buffer in the worst case before the kernel ring buffer flips over, the size is specified as a power of 2. The total amount of contributions made by each CPU must be greater than half of the default kernel ring buffer size (1 << LOG_BUF_SHIFT bytes) in order to trigger an increase upon bootup. The kernel ring buffer is increased to the next power of two that would fit the required minimum kernel ring buffer size plus the additional CPU contribution. For example if LOG_BUF_SHIFT is 18 (256 KB) you'd require at least 128 KB contributions by other CPUs in order to trigger an increase of the kernel ring buffer. With a LOG_CPU_BUF_SHIFT of 12 (4 KB) you'd require at least anything over > 64 possible CPUs to trigger an increase. If you had 128 possible CPUs the amount of minimum required kernel ring buffer bumps to: ((1 << 18) + ((128 - 1) * (1 << 12))) / 1024 = 764 KB Since we require the ring buffer to be a power of two the new required size would be 1024 KB. This CPU contributions are ignored when the "log_buf_len" kernel parameter is used as it forces the exact size of the ring buffer to an expected power of two value. [pmladek@suse.cz: fix build] Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.cz> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Tested-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Arun KS <arunks.linux@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07 07:08:56 +08:00
Select the minimal kernel log buffer size as a power of 2.
The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
parameter, see below. Any higher size also might be forced
by "log_buf_len" boot parameter.
let LOG_BUF_SHIFT default to 17 16 kB is often no longer enough for a normal boot of an UP system. And even less when people e.g. use suspend. 17 seems to be a more reasonable default for current kernels on current hardware (it's just the default, anyone who is memory limited can still lower it). Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 15:58:58 +08:00
Examples:
printk: allow increasing the ring buffer depending on the number of CPUs The default size of the ring buffer is too small for machines with a large amount of CPUs under heavy load. What ends up happening when debugging is the ring buffer overlaps and chews up old messages making debugging impossible unless the size is passed as a kernel parameter. An idle system upon boot up will on average spew out only about one or two extra lines but where this really matters is on heavy load and that will vary widely depending on the system and environment. There are mechanisms to help increase the kernel ring buffer for tracing through debugfs, and those interfaces even allow growing the kernel ring buffer per CPU. We also have a static value which can be passed upon boot. Relying on debugfs however is not ideal for production, and relying on the value passed upon bootup is can only used *after* an issue has creeped up. Instead of being reactive this adds a proactive measure which lets you scale the amount of contributions you'd expect to the kernel ring buffer under load by each CPU in the worst case scenario. We use num_possible_cpus() to avoid complexities which could be introduced by dynamically changing the ring buffer size at run time, num_possible_cpus() lets us use the upper limit on possible number of CPUs therefore avoiding having to deal with hotplugging CPUs on and off. This introduces the kernel configuration option LOG_CPU_MAX_BUF_SHIFT which is used to specify the maximum amount of contributions to the kernel ring buffer in the worst case before the kernel ring buffer flips over, the size is specified as a power of 2. The total amount of contributions made by each CPU must be greater than half of the default kernel ring buffer size (1 << LOG_BUF_SHIFT bytes) in order to trigger an increase upon bootup. The kernel ring buffer is increased to the next power of two that would fit the required minimum kernel ring buffer size plus the additional CPU contribution. For example if LOG_BUF_SHIFT is 18 (256 KB) you'd require at least 128 KB contributions by other CPUs in order to trigger an increase of the kernel ring buffer. With a LOG_CPU_BUF_SHIFT of 12 (4 KB) you'd require at least anything over > 64 possible CPUs to trigger an increase. If you had 128 possible CPUs the amount of minimum required kernel ring buffer bumps to: ((1 << 18) + ((128 - 1) * (1 << 12))) / 1024 = 764 KB Since we require the ring buffer to be a power of two the new required size would be 1024 KB. This CPU contributions are ignored when the "log_buf_len" kernel parameter is used as it forces the exact size of the ring buffer to an expected power of two value. [pmladek@suse.cz: fix build] Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.cz> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Tested-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Arun KS <arunks.linux@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07 07:08:56 +08:00
17 => 128 KB
let LOG_BUF_SHIFT default to 17 16 kB is often no longer enough for a normal boot of an UP system. And even less when people e.g. use suspend. 17 seems to be a more reasonable default for current kernels on current hardware (it's just the default, anyone who is memory limited can still lower it). Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 15:58:58 +08:00
16 => 64 KB
printk: allow increasing the ring buffer depending on the number of CPUs The default size of the ring buffer is too small for machines with a large amount of CPUs under heavy load. What ends up happening when debugging is the ring buffer overlaps and chews up old messages making debugging impossible unless the size is passed as a kernel parameter. An idle system upon boot up will on average spew out only about one or two extra lines but where this really matters is on heavy load and that will vary widely depending on the system and environment. There are mechanisms to help increase the kernel ring buffer for tracing through debugfs, and those interfaces even allow growing the kernel ring buffer per CPU. We also have a static value which can be passed upon boot. Relying on debugfs however is not ideal for production, and relying on the value passed upon bootup is can only used *after* an issue has creeped up. Instead of being reactive this adds a proactive measure which lets you scale the amount of contributions you'd expect to the kernel ring buffer under load by each CPU in the worst case scenario. We use num_possible_cpus() to avoid complexities which could be introduced by dynamically changing the ring buffer size at run time, num_possible_cpus() lets us use the upper limit on possible number of CPUs therefore avoiding having to deal with hotplugging CPUs on and off. This introduces the kernel configuration option LOG_CPU_MAX_BUF_SHIFT which is used to specify the maximum amount of contributions to the kernel ring buffer in the worst case before the kernel ring buffer flips over, the size is specified as a power of 2. The total amount of contributions made by each CPU must be greater than half of the default kernel ring buffer size (1 << LOG_BUF_SHIFT bytes) in order to trigger an increase upon bootup. The kernel ring buffer is increased to the next power of two that would fit the required minimum kernel ring buffer size plus the additional CPU contribution. For example if LOG_BUF_SHIFT is 18 (256 KB) you'd require at least 128 KB contributions by other CPUs in order to trigger an increase of the kernel ring buffer. With a LOG_CPU_BUF_SHIFT of 12 (4 KB) you'd require at least anything over > 64 possible CPUs to trigger an increase. If you had 128 possible CPUs the amount of minimum required kernel ring buffer bumps to: ((1 << 18) + ((128 - 1) * (1 << 12))) / 1024 = 764 KB Since we require the ring buffer to be a power of two the new required size would be 1024 KB. This CPU contributions are ignored when the "log_buf_len" kernel parameter is used as it forces the exact size of the ring buffer to an expected power of two value. [pmladek@suse.cz: fix build] Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.cz> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Tested-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Arun KS <arunks.linux@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07 07:08:56 +08:00
15 => 32 KB
14 => 16 KB
Move LOG_BUF_SHIFT to a more sensible place Several people have observed that perhaps LOG_BUF_SHIFT should be in a more obvious place than under DEBUG_KERNEL. Under some circumstances (such as the PARISC architecture), DEBUG_KERNEL can increase kernel size, which is an undesirable trade off for something as trivial as increasing the kernel log buffer size. Instead, move LOG_BUF_SHIFT into "General Setup", so that people are more likely to be able to change it such a circumstance that the default buffer size is insufficient. Signed-off-by: Alistair John Strachan <s0348365@sms.ed.ac.uk> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 15:31:15 +08:00
13 => 8 KB
12 => 4 KB
printk: allow increasing the ring buffer depending on the number of CPUs The default size of the ring buffer is too small for machines with a large amount of CPUs under heavy load. What ends up happening when debugging is the ring buffer overlaps and chews up old messages making debugging impossible unless the size is passed as a kernel parameter. An idle system upon boot up will on average spew out only about one or two extra lines but where this really matters is on heavy load and that will vary widely depending on the system and environment. There are mechanisms to help increase the kernel ring buffer for tracing through debugfs, and those interfaces even allow growing the kernel ring buffer per CPU. We also have a static value which can be passed upon boot. Relying on debugfs however is not ideal for production, and relying on the value passed upon bootup is can only used *after* an issue has creeped up. Instead of being reactive this adds a proactive measure which lets you scale the amount of contributions you'd expect to the kernel ring buffer under load by each CPU in the worst case scenario. We use num_possible_cpus() to avoid complexities which could be introduced by dynamically changing the ring buffer size at run time, num_possible_cpus() lets us use the upper limit on possible number of CPUs therefore avoiding having to deal with hotplugging CPUs on and off. This introduces the kernel configuration option LOG_CPU_MAX_BUF_SHIFT which is used to specify the maximum amount of contributions to the kernel ring buffer in the worst case before the kernel ring buffer flips over, the size is specified as a power of 2. The total amount of contributions made by each CPU must be greater than half of the default kernel ring buffer size (1 << LOG_BUF_SHIFT bytes) in order to trigger an increase upon bootup. The kernel ring buffer is increased to the next power of two that would fit the required minimum kernel ring buffer size plus the additional CPU contribution. For example if LOG_BUF_SHIFT is 18 (256 KB) you'd require at least 128 KB contributions by other CPUs in order to trigger an increase of the kernel ring buffer. With a LOG_CPU_BUF_SHIFT of 12 (4 KB) you'd require at least anything over > 64 possible CPUs to trigger an increase. If you had 128 possible CPUs the amount of minimum required kernel ring buffer bumps to: ((1 << 18) + ((128 - 1) * (1 << 12))) / 1024 = 764 KB Since we require the ring buffer to be a power of two the new required size would be 1024 KB. This CPU contributions are ignored when the "log_buf_len" kernel parameter is used as it forces the exact size of the ring buffer to an expected power of two value. [pmladek@suse.cz: fix build] Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.cz> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Tested-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Arun KS <arunks.linux@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07 07:08:56 +08:00
config LOG_CPU_MAX_BUF_SHIFT
int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
printk: don't bother using LOG_CPU_MAX_BUF_SHIFT on !SMP When configuring a uniprocessor kernel, don't bother the user with an irrelevant LOG_CPU_MAX_BUF_SHIFT question, and don't build the unused code. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 06:51:11 +08:00
depends on SMP
printk: allow increasing the ring buffer depending on the number of CPUs The default size of the ring buffer is too small for machines with a large amount of CPUs under heavy load. What ends up happening when debugging is the ring buffer overlaps and chews up old messages making debugging impossible unless the size is passed as a kernel parameter. An idle system upon boot up will on average spew out only about one or two extra lines but where this really matters is on heavy load and that will vary widely depending on the system and environment. There are mechanisms to help increase the kernel ring buffer for tracing through debugfs, and those interfaces even allow growing the kernel ring buffer per CPU. We also have a static value which can be passed upon boot. Relying on debugfs however is not ideal for production, and relying on the value passed upon bootup is can only used *after* an issue has creeped up. Instead of being reactive this adds a proactive measure which lets you scale the amount of contributions you'd expect to the kernel ring buffer under load by each CPU in the worst case scenario. We use num_possible_cpus() to avoid complexities which could be introduced by dynamically changing the ring buffer size at run time, num_possible_cpus() lets us use the upper limit on possible number of CPUs therefore avoiding having to deal with hotplugging CPUs on and off. This introduces the kernel configuration option LOG_CPU_MAX_BUF_SHIFT which is used to specify the maximum amount of contributions to the kernel ring buffer in the worst case before the kernel ring buffer flips over, the size is specified as a power of 2. The total amount of contributions made by each CPU must be greater than half of the default kernel ring buffer size (1 << LOG_BUF_SHIFT bytes) in order to trigger an increase upon bootup. The kernel ring buffer is increased to the next power of two that would fit the required minimum kernel ring buffer size plus the additional CPU contribution. For example if LOG_BUF_SHIFT is 18 (256 KB) you'd require at least 128 KB contributions by other CPUs in order to trigger an increase of the kernel ring buffer. With a LOG_CPU_BUF_SHIFT of 12 (4 KB) you'd require at least anything over > 64 possible CPUs to trigger an increase. If you had 128 possible CPUs the amount of minimum required kernel ring buffer bumps to: ((1 << 18) + ((128 - 1) * (1 << 12))) / 1024 = 764 KB Since we require the ring buffer to be a power of two the new required size would be 1024 KB. This CPU contributions are ignored when the "log_buf_len" kernel parameter is used as it forces the exact size of the ring buffer to an expected power of two value. [pmladek@suse.cz: fix build] Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.cz> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Tested-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Arun KS <arunks.linux@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07 07:08:56 +08:00
range 0 21
default 12 if !BASE_SMALL
default 0 if BASE_SMALL
init/Kconfig: Hide printk log config if CONFIG_PRINTK=n The buffers sized by CONFIG_LOG_BUF_SHIFT and CONFIG_LOG_CPU_MAX_BUF_SHIFT do not exist if CONFIG_PRINTK=n, so don't ask about their size at all. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: stable <stable@vger.kernel.org>
2014-10-04 07:00:54 +08:00
depends on PRINTK
printk: allow increasing the ring buffer depending on the number of CPUs The default size of the ring buffer is too small for machines with a large amount of CPUs under heavy load. What ends up happening when debugging is the ring buffer overlaps and chews up old messages making debugging impossible unless the size is passed as a kernel parameter. An idle system upon boot up will on average spew out only about one or two extra lines but where this really matters is on heavy load and that will vary widely depending on the system and environment. There are mechanisms to help increase the kernel ring buffer for tracing through debugfs, and those interfaces even allow growing the kernel ring buffer per CPU. We also have a static value which can be passed upon boot. Relying on debugfs however is not ideal for production, and relying on the value passed upon bootup is can only used *after* an issue has creeped up. Instead of being reactive this adds a proactive measure which lets you scale the amount of contributions you'd expect to the kernel ring buffer under load by each CPU in the worst case scenario. We use num_possible_cpus() to avoid complexities which could be introduced by dynamically changing the ring buffer size at run time, num_possible_cpus() lets us use the upper limit on possible number of CPUs therefore avoiding having to deal with hotplugging CPUs on and off. This introduces the kernel configuration option LOG_CPU_MAX_BUF_SHIFT which is used to specify the maximum amount of contributions to the kernel ring buffer in the worst case before the kernel ring buffer flips over, the size is specified as a power of 2. The total amount of contributions made by each CPU must be greater than half of the default kernel ring buffer size (1 << LOG_BUF_SHIFT bytes) in order to trigger an increase upon bootup. The kernel ring buffer is increased to the next power of two that would fit the required minimum kernel ring buffer size plus the additional CPU contribution. For example if LOG_BUF_SHIFT is 18 (256 KB) you'd require at least 128 KB contributions by other CPUs in order to trigger an increase of the kernel ring buffer. With a LOG_CPU_BUF_SHIFT of 12 (4 KB) you'd require at least anything over > 64 possible CPUs to trigger an increase. If you had 128 possible CPUs the amount of minimum required kernel ring buffer bumps to: ((1 << 18) + ((128 - 1) * (1 << 12))) / 1024 = 764 KB Since we require the ring buffer to be a power of two the new required size would be 1024 KB. This CPU contributions are ignored when the "log_buf_len" kernel parameter is used as it forces the exact size of the ring buffer to an expected power of two value. [pmladek@suse.cz: fix build] Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.cz> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Tested-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Arun KS <arunks.linux@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07 07:08:56 +08:00
help
This option allows to increase the default ring buffer size
according to the number of CPUs. The value defines the contribution
of each CPU as a power of 2. The used space is typically only few
lines however it might be much more when problems are reported,
e.g. backtraces.
The increased size means that a new buffer has to be allocated and
the original static one is unused. It makes sense only on systems
with more CPUs. Therefore this value is used only when the sum of
contributions is greater than the half of the default kernel ring
buffer as defined by LOG_BUF_SHIFT. The default values are set
so that more than 64 CPUs are needed to trigger the allocation.
Also this option is ignored when "log_buf_len" kernel parameter is
used as it forces an exact (power of two) size of the ring buffer.
The number of possible CPUs is used for this computation ignoring
init: fix Kconfig text [jkosina@suse.cz: folded another fix on top on the same line as spotted by Randy Dunlap] Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-06-05 16:47:02 +08:00
hotplugging making the computation optimal for the worst case
scenario while allowing a simple algorithm to be used from bootup.
printk: allow increasing the ring buffer depending on the number of CPUs The default size of the ring buffer is too small for machines with a large amount of CPUs under heavy load. What ends up happening when debugging is the ring buffer overlaps and chews up old messages making debugging impossible unless the size is passed as a kernel parameter. An idle system upon boot up will on average spew out only about one or two extra lines but where this really matters is on heavy load and that will vary widely depending on the system and environment. There are mechanisms to help increase the kernel ring buffer for tracing through debugfs, and those interfaces even allow growing the kernel ring buffer per CPU. We also have a static value which can be passed upon boot. Relying on debugfs however is not ideal for production, and relying on the value passed upon bootup is can only used *after* an issue has creeped up. Instead of being reactive this adds a proactive measure which lets you scale the amount of contributions you'd expect to the kernel ring buffer under load by each CPU in the worst case scenario. We use num_possible_cpus() to avoid complexities which could be introduced by dynamically changing the ring buffer size at run time, num_possible_cpus() lets us use the upper limit on possible number of CPUs therefore avoiding having to deal with hotplugging CPUs on and off. This introduces the kernel configuration option LOG_CPU_MAX_BUF_SHIFT which is used to specify the maximum amount of contributions to the kernel ring buffer in the worst case before the kernel ring buffer flips over, the size is specified as a power of 2. The total amount of contributions made by each CPU must be greater than half of the default kernel ring buffer size (1 << LOG_BUF_SHIFT bytes) in order to trigger an increase upon bootup. The kernel ring buffer is increased to the next power of two that would fit the required minimum kernel ring buffer size plus the additional CPU contribution. For example if LOG_BUF_SHIFT is 18 (256 KB) you'd require at least 128 KB contributions by other CPUs in order to trigger an increase of the kernel ring buffer. With a LOG_CPU_BUF_SHIFT of 12 (4 KB) you'd require at least anything over > 64 possible CPUs to trigger an increase. If you had 128 possible CPUs the amount of minimum required kernel ring buffer bumps to: ((1 << 18) + ((128 - 1) * (1 << 12))) / 1024 = 764 KB Since we require the ring buffer to be a power of two the new required size would be 1024 KB. This CPU contributions are ignored when the "log_buf_len" kernel parameter is used as it forces the exact size of the ring buffer to an expected power of two value. [pmladek@suse.cz: fix build] Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.cz> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Tested-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Arun KS <arunks.linux@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07 07:08:56 +08:00
Examples shift values and their meaning:
17 => 128 KB for each CPU
16 => 64 KB for each CPU
15 => 32 KB for each CPU
14 => 16 KB for each CPU
13 => 8 KB for each CPU
12 => 4 KB for each CPU
printk: rename nmi.c and exported api A preparation patch for printk_safe work. No functional change. - rename nmi.c to print_safe.c - add `printk_safe' prefix to some (which used both by printk-safe and printk-nmi) of the exported functions. Link: http://lkml.kernel.org/r/20161227141611.940-3-sergey.senozhatsky@gmail.com Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jan Kara <jack@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Calvin Owens <calvinowens@fb.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2016-12-27 22:16:05 +08:00
config PRINTK_SAFE_LOG_BUF_SHIFT
int "Temporary per-CPU printk log buffer size (12 => 4KB, 13 => 8KB)"
printk/nmi: increase the size of NMI buffer and make it configurable Testing has shown that the backtrace sometimes does not fit into the 4kB temporary buffer that is used in NMI context. The warnings are gone when I double the temporary buffer size. This patch doubles the buffer size and makes it configurable. Note that this problem existed even in the x86-specific implementation that was added by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). Nobody noticed it because it did not print any warnings. Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jiri Kosina <jkosina@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: David Miller <davem@davemloft.net> Cc: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21 08:00:39 +08:00
range 10 21
default 13
printk: rename nmi.c and exported api A preparation patch for printk_safe work. No functional change. - rename nmi.c to print_safe.c - add `printk_safe' prefix to some (which used both by printk-safe and printk-nmi) of the exported functions. Link: http://lkml.kernel.org/r/20161227141611.940-3-sergey.senozhatsky@gmail.com Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jan Kara <jack@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Calvin Owens <calvinowens@fb.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2016-12-27 22:16:05 +08:00
depends on PRINTK
printk/nmi: increase the size of NMI buffer and make it configurable Testing has shown that the backtrace sometimes does not fit into the 4kB temporary buffer that is used in NMI context. The warnings are gone when I double the temporary buffer size. This patch doubles the buffer size and makes it configurable. Note that this problem existed even in the x86-specific implementation that was added by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). Nobody noticed it because it did not print any warnings. Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jiri Kosina <jkosina@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: David Miller <davem@davemloft.net> Cc: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21 08:00:39 +08:00
help
printk: rename nmi.c and exported api A preparation patch for printk_safe work. No functional change. - rename nmi.c to print_safe.c - add `printk_safe' prefix to some (which used both by printk-safe and printk-nmi) of the exported functions. Link: http://lkml.kernel.org/r/20161227141611.940-3-sergey.senozhatsky@gmail.com Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jan Kara <jack@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Calvin Owens <calvinowens@fb.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2016-12-27 22:16:05 +08:00
Select the size of an alternate printk per-CPU buffer where messages
printed from usafe contexts are temporary stored. One example would
be NMI messages, another one - printk recursion. The messages are
copied to the main log buffer in a safe context to avoid a deadlock.
The value defines the size as a power of 2.
printk/nmi: increase the size of NMI buffer and make it configurable Testing has shown that the backtrace sometimes does not fit into the 4kB temporary buffer that is used in NMI context. The warnings are gone when I double the temporary buffer size. This patch doubles the buffer size and makes it configurable. Note that this problem existed even in the x86-specific implementation that was added by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). Nobody noticed it because it did not print any warnings. Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jiri Kosina <jkosina@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: David Miller <davem@davemloft.net> Cc: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21 08:00:39 +08:00
printk: rename nmi.c and exported api A preparation patch for printk_safe work. No functional change. - rename nmi.c to print_safe.c - add `printk_safe' prefix to some (which used both by printk-safe and printk-nmi) of the exported functions. Link: http://lkml.kernel.org/r/20161227141611.940-3-sergey.senozhatsky@gmail.com Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jan Kara <jack@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Calvin Owens <calvinowens@fb.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2016-12-27 22:16:05 +08:00
Those messages are rare and limited. The largest one is when
printk/nmi: increase the size of NMI buffer and make it configurable Testing has shown that the backtrace sometimes does not fit into the 4kB temporary buffer that is used in NMI context. The warnings are gone when I double the temporary buffer size. This patch doubles the buffer size and makes it configurable. Note that this problem existed even in the x86-specific implementation that was added by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). Nobody noticed it because it did not print any warnings. Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jiri Kosina <jkosina@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: David Miller <davem@davemloft.net> Cc: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21 08:00:39 +08:00
a backtrace is printed. It usually fits into 4KB. Select
8KB if you want to be on the safe side.
Examples:
17 => 128 KB for each CPU
16 => 64 KB for each CPU
15 => 32 KB for each CPU
14 => 16 KB for each CPU
13 => 8 KB for each CPU
12 => 4 KB for each CPU
sched, x86: add HAVE_UNSTABLE_SCHED_CLOCK add the HAVE_UNSTABLE_SCHED_CLOCK, for architectures to select. the next change utilizes it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-06 05:19:50 +08:00
#
# Architectures with an unreliable sched_clock() should select this:
#
config HAVE_UNSTABLE_SCHED_CLOCK
bool
sched_clock: Make ARM's sched_clock generic for all architectures Nothing about the sched_clock implementation in the ARM port is specific to the architecture. Generalize the code so that other architectures can use it by selecting GENERIC_SCHED_CLOCK. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> [jstultz: Merge minor collisions with other patches in my tree] Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-06-02 14:39:40 +08:00
config GENERIC_SCHED_CLOCK
bool
sched/uclamp: Add CPU's clamp buckets refcounting Utilization clamping allows to clamp the CPU's utilization within a [util_min, util_max] range, depending on the set of RUNNABLE tasks on that CPU. Each task references two "clamp buckets" defining its minimum and maximum (util_{min,max}) utilization "clamp values". A CPU's clamp bucket is active if there is at least one RUNNABLE tasks enqueued on that CPU and refcounting that bucket. When a task is {en,de}queued {on,from} a rq, the set of active clamp buckets on that CPU can change. If the set of active clamp buckets changes for a CPU a new "aggregated" clamp value is computed for that CPU. This is because each clamp bucket enforces a different utilization clamp value. Clamp values are always MAX aggregated for both util_min and util_max. This ensures that no task can affect the performance of other co-scheduled tasks which are more boosted (i.e. with higher util_min clamp) or less capped (i.e. with higher util_max clamp). A task has: task_struct::uclamp[clamp_id]::bucket_id to track the "bucket index" of the CPU's clamp bucket it refcounts while enqueued, for each clamp index (clamp_id). A runqueue has: rq::uclamp[clamp_id]::bucket[bucket_id].tasks to track how many RUNNABLE tasks on that CPU refcount each clamp bucket (bucket_id) of a clamp index (clamp_id). It also has a: rq::uclamp[clamp_id]::bucket[bucket_id].value to track the clamp value of each clamp bucket (bucket_id) of a clamp index (clamp_id). The rq::uclamp::bucket[clamp_id][] array is scanned every time it's needed to find a new MAX aggregated clamp value for a clamp_id. This operation is required only when it's dequeued the last task of a clamp bucket tracking the current MAX aggregated clamp value. In this case, the CPU is either entering IDLE or going to schedule a less boosted or more clamped task. The expected number of different clamp values configured at build time is small enough to fit the full unordered array into a single cache line, for configurations of up to 7 buckets. Add to struct rq the basic data structures required to refcount the number of RUNNABLE tasks for each clamp bucket. Add also the max aggregation required to update the rq's clamp value at each enqueue/dequeue event. Use a simple linear mapping of clamp values into clamp buckets. Pre-compute and cache bucket_id to avoid integer divisions at enqueue/dequeue time. Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alessio Balsini <balsini@android.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Perret <quentin.perret@arm.com> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Steve Muckle <smuckle@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@google.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: https://lkml.kernel.org/r/20190621084217.8167-2-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-21 16:42:02 +08:00
menu "Scheduler features"
config UCLAMP_TASK
bool "Enable utilization clamping for RT/FAIR tasks"
depends on CPU_FREQ_GOV_SCHEDUTIL
help
This feature enables the scheduler to track the clamped utilization
of each CPU based on RUNNABLE tasks scheduled on that CPU.
With this option, the user can specify the min and max CPU
utilization allowed for RUNNABLE tasks. The max utilization defines
the maximum frequency a task should use while the min utilization
defines the minimum frequency it should use.
Both min and max utilization clamp values are hints to the scheduler,
aiming at improving its frequency selection policy, but they do not
enforce or grant any specific bandwidth for tasks.
If in doubt, say N.
config UCLAMP_BUCKETS_COUNT
int "Number of supported utilization clamp buckets"
range 5 20
default 5
depends on UCLAMP_TASK
help
Defines the number of clamp buckets to use. The range of each bucket
will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the
number of clamp buckets the finer their granularity and the higher
the precision of clamping aggregation and tracking at run-time.
For example, with the minimum configuration value we will have 5
clamp buckets tracking 20% utilization each. A 25% boosted tasks will
be refcounted in the [20..39]% bucket and will set the bucket clamp
effective value to 25%.
If a second 30% boosted task should be co-scheduled on the same CPU,
that task will be refcounted in the same bucket of the first task and
it will boost the bucket clamp effective value to 30%.
The clamp effective value of a bucket is reset to its nominal value
(20% in the example above) when there are no more tasks refcounted in
that bucket.
An additional boost/capping margin can be added to some tasks. In the
example above the 25% task will be boosted to 30% until it exits the
CPU. If that should be considered not acceptable on certain systems,
it's always possible to reduce the margin by increasing the number of
clamp buckets to trade off used memory for run-time tracking
precision.
If in doubt, use the default value.
endmenu
mm: numa: pte_numa() and pmd_numa() Implement pte_numa and pmd_numa. We must atomically set the numa bit and clear the present bit to define a pte_numa or pmd_numa. Once a pte or pmd has been set as pte_numa or pmd_numa, the next time a thread touches a virtual address in the corresponding virtual range, a NUMA hinting page fault will trigger. The NUMA hinting page fault will clear the NUMA bit and set the present bit again to resolve the page fault. The expectation is that a NUMA hinting page fault is used as part of a placement policy that decides if a page should remain on the current node or migrated to a different node. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de>
2012-10-04 07:50:47 +08:00
#
# For architectures that want to enable the support for NUMA-affine scheduler
# balancing logic:
#
config ARCH_SUPPORTS_NUMA_BALANCING
bool
mm: send one IPI per CPU to TLB flush all entries after unmapping pages An IPI is sent to flush remote TLBs when a page is unmapped that was potentially accesssed by other CPUs. There are many circumstances where this happens but the obvious one is kswapd reclaiming pages belonging to a running process as kswapd and the task are likely running on separate CPUs. On small machines, this is not a significant problem but as machine gets larger with more cores and more memory, the cost of these IPIs can be high. This patch uses a simple structure that tracks CPUs that potentially have TLB entries for pages being unmapped. When the unmapping is complete, the full TLB is flushed on the assumption that a refill cost is lower than flushing individual entries. Architectures wishing to do this must give the following guarantee. If a clean page is unmapped and not immediately flushed, the architecture must guarantee that a write to that linear address from a CPU with a cached TLB entry will trap a page fault. This is essentially what the kernel already depends on but the window is much larger with this patch applied and is worth highlighting. The architecture should consider whether the cost of the full TLB flush is higher than sending an IPI to flush each individual entry. An additional architecture helper called flush_tlb_local is required. It's a trivial wrapper with some accounting in the x86 case. The impact of this patch depends on the workload as measuring any benefit requires both mapped pages co-located on the LRU and memory pressure. The case with the biggest impact is multiple processes reading mapped pages taken from the vm-scalability test suite. The test case uses NR_CPU readers of mapped files that consume 10*RAM. Linear mapped reader on a 4-node machine with 64G RAM and 48 CPUs 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 Ops lru-file-mmap-read-elapsed 159.62 ( 0.00%) 120.68 ( 24.40%) Ops lru-file-mmap-read-time_range 30.59 ( 0.00%) 2.80 ( 90.85%) Ops lru-file-mmap-read-time_stddv 6.70 ( 0.00%) 0.64 ( 90.38%) 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 User 581.00 611.43 System 5804.93 4111.76 Elapsed 161.03 122.12 This is showing that the readers completed 24.40% faster with 29% less system CPU time. From vmstats, it is known that the vanilla kernel was interrupted roughly 900K times per second during the steady phase of the test and the patched kernel was interrupts 180K times per second. The impact is lower on a single socket machine. 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 Ops lru-file-mmap-read-elapsed 25.33 ( 0.00%) 20.38 ( 19.54%) Ops lru-file-mmap-read-time_range 0.91 ( 0.00%) 1.44 (-58.24%) Ops lru-file-mmap-read-time_stddv 0.28 ( 0.00%) 0.47 (-65.34%) 4.2.0-rc1 4.2.0-rc1 vanilla flushfull-v7 User 58.09 57.64 System 111.82 76.56 Elapsed 27.29 22.55 It's still a noticeable improvement with vmstat showing interrupts went from roughly 500K per second to 45K per second. The patch will have no impact on workloads with no memory pressure or have relatively few mapped pages. It will have an unpredictable impact on the workload running on the CPU being flushed as it'll depend on how many TLB entries need to be refilled and how long that takes. Worst case, the TLB will be completely cleared of active entries when the target PFNs were not resident at all. [sasha.levin@oracle.com: trace tlb flush after disabling preemption in try_to_unmap_flush] Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05 06:47:32 +08:00
#
# For architectures that prefer to flush all TLBs after a number of pages
# are unmapped instead of sending one IPI per page to flush. The architecture
# must provide guarantees on what happens if a clean TLB cache entry is
# written after the unmap. Details are in mm/rmap.c near the check for
# should_defer_flush. The architecture should also consider if the full flush
# and the refill costs are offset by the savings of sending fewer IPIs.
config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
bool
int128: move __uint128_t compiler test to Kconfig In order to use 128-bit integer arithmetic in C code, the architecture needs to have declared support for it by setting ARCH_SUPPORTS_INT128, and it requires a version of the toolchain that supports this at build time. This is why all existing tests for ARCH_SUPPORTS_INT128 also test whether __SIZEOF_INT128__ is defined, since this is only the case for compilers that can support 128-bit integers. Let's fold this additional test into the Kconfig declaration of ARCH_SUPPORTS_INT128 so that we can also use the symbol in Makefiles, e.g., to decide whether a certain object needs to be included in the first place. Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-11-08 20:22:27 +08:00
config CC_HAS_INT128
int128: fix __uint128_t compiler test in Kconfig The support for __uint128_t is dependent on the target bit size. GCC that defaults to the 32-bit can still build the 64-bit kernel with -m64 flag passed. However, $(cc-option,-D__SIZEOF_INT128__=0) is evaluated against the default machine bit, which may not match to the kernel it is building. Theoretically, this could be evaluated separately for 64BIT/32BIT. config CC_HAS_INT128 bool default !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) if 64BIT default !$(cc-option,$(m32-flag) -D__SIZEOF_INT128__=0) I simplified it more because the 32-bit compiler is unlikely to support __uint128_t. Fixes: c12d3362a74b ("int128: move __uint128_t compiler test to Kconfig") Reported-by: George Spelvin <lkml@sdf.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: George Spelvin <lkml@sdf.org>
2020-03-10 18:12:50 +08:00
def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
int128: move __uint128_t compiler test to Kconfig In order to use 128-bit integer arithmetic in C code, the architecture needs to have declared support for it by setting ARCH_SUPPORTS_INT128, and it requires a version of the toolchain that supports this at build time. This is why all existing tests for ARCH_SUPPORTS_INT128 also test whether __SIZEOF_INT128__ is defined, since this is only the case for compilers that can support 128-bit integers. Let's fold this additional test into the Kconfig declaration of ARCH_SUPPORTS_INT128 so that we can also use the symbol in Makefiles, e.g., to decide whether a certain object needs to be included in the first place. Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-11-08 20:22:27 +08:00
math64: Add mul_u64_u32_shr() Introduce mul_u64_u32_shr() as proposed by Andy a while back; it allows using 64x64->128 muls on 64bit archs and recent GCC which defines __SIZEOF_INT128__ and __int128. (This new method will be used by the scheduler.) Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: fweisbec@gmail.com Cc: Andy Lutomirski <luto@amacapital.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-hxjoeuzmrcaumR0uZwjpe2pv@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-19 01:27:06 +08:00
#
# For architectures that know their GCC __int128 support is sound
#
config ARCH_SUPPORTS_INT128
bool
mm: numa: pte_numa() and pmd_numa() Implement pte_numa and pmd_numa. We must atomically set the numa bit and clear the present bit to define a pte_numa or pmd_numa. Once a pte or pmd has been set as pte_numa or pmd_numa, the next time a thread touches a virtual address in the corresponding virtual range, a NUMA hinting page fault will trigger. The NUMA hinting page fault will clear the NUMA bit and set the present bit again to resolve the page fault. The expectation is that a NUMA hinting page fault is used as part of a placement policy that decides if a page should remain on the current node or migrated to a different node. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de>
2012-10-04 07:50:47 +08:00
# For architectures that (ab)use NUMA to represent different memory regions
# all cpu-local but of different latencies, such as SuperH.
#
config ARCH_WANT_NUMA_VARIABLE_LOCALITY
bool
config NUMA_BALANCING
bool "Memory placement aware NUMA scheduler"
depends on ARCH_SUPPORTS_NUMA_BALANCING
depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
depends on SMP && NUMA && MIGRATION
help
This option adds support for automatic NUMA aware memory/task placement.
The mechanism is quite primitive and is based on migrating memory when
NUMA: fix typos in Kconfig help text Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-08-13 23:06:50 +08:00
it has references to the node the task is running on.
mm: numa: pte_numa() and pmd_numa() Implement pte_numa and pmd_numa. We must atomically set the numa bit and clear the present bit to define a pte_numa or pmd_numa. Once a pte or pmd has been set as pte_numa or pmd_numa, the next time a thread touches a virtual address in the corresponding virtual range, a NUMA hinting page fault will trigger. The NUMA hinting page fault will clear the NUMA bit and set the present bit again to resolve the page fault. The expectation is that a NUMA hinting page fault is used as part of a placement policy that decides if a page should remain on the current node or migrated to a different node. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de>
2012-10-04 07:50:47 +08:00
This system will be inactive on UMA systems.
mm/numa balancing: rearrange Kconfig entry Add the default enable config option after the NUMA_BALANCING option so that it appears related in the nconfig interface. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-11 07:43:37 +08:00
config NUMA_BALANCING_DEFAULT_ENABLED
bool "Automatically enable NUMA aware memory/task placement"
default y
depends on NUMA_BALANCING
help
If set, automatic NUMA balancing will be enabled if running on a NUMA
machine.
cgroups: clean up Kconfig - move CONFIG_PROC_PID_CPUSET into cgroup menu - move MM_OWNER to the bottom for better menu indent - fix typos - use tabs not spaces Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-16 05:50:58 +08:00
menuconfig CGROUPS
kconfig: use bool instead of boolean for type definition attributes Support for keyword 'boolean' will be dropped later on. No functional change. Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com Signed-off-by: Christoph Jaeger <cj@linux.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-12-21 04:41:11 +08:00
bool "Control Group support"
cgroup: convert to kernfs cgroup filesystem code was derived from the original sysfs implementation which was heavily intertwined with vfs objects and locking with the goal of re-using the existing vfs infrastructure. That experiment turned out rather disastrous and sysfs switched, a long time ago, to distributed filesystem model where a separate representation is maintained which is queried by vfs. Unfortunately, cgroup stuck with the failed experiment all these years and accumulated even more problems over time. Locking and object lifetime management being entangled with vfs is probably the most egregious. vfs is never designed to be misused like this and cgroup ends up jumping through various convoluted dancing to make things work. Even then, operations across multiple cgroups can't be done safely as it'll deadlock with rename locking. Recently, kernfs is separated out from sysfs so that it can be used by users other than sysfs. This patch converts cgroup to use kernfs, which will bring the following benefits. * Separation from vfs internals. Locking and object lifetime management is contained in cgroup proper making things a lot simpler. This removes significant amount of locking convolutions, hairy object lifetime rules and the restriction on multi-cgroup operations. * Can drop a lot of code to implement filesystem interface as most are provided by kernfs. * Proper "severing" semantics, which allows controllers to not worry about lingering file accesses after offline. While the preceding patches did as much as possible to make the transition less painful, large part of the conversion has to be one discrete step making this patch rather large. The rest of the commit message lists notable changes in different areas. Overall ------- * vfs constructs replaced with kernfs ones. cgroup->dentry w/ ->kn, cgroupfs_root->sb w/ ->kf_root. * All dentry accessors are removed. Helpers to map from kernfs constructs are added. * All vfs plumbing around dentry, inode and bdi removed. * cgroup_mount() now directly looks for matching root and then proceeds to create a new one if not found. Synchronization and object lifetime ----------------------------------- * vfs inode locking removed. Among other things, this removes the need for the convolution in cgroup_cfts_commit(). Future patches will further simplify it. * vfs refcnting replaced with cgroup internal ones. cgroup->refcnt, cgroupfs_root->refcnt added. cgroup_put_root() now directly puts root->refcnt and when it reaches zero proceeds to destroy it thus merging cgroup_put_root() and the former cgroup_kill_sb(). Simliarly, cgroup_put() now directly schedules cgroup_free_rcu() when refcnt reaches zero. * Unlike before, kernfs objects don't hold onto cgroup objects. When cgroup destroys a kernfs node, all existing operations are drained and the association is broken immediately. The same for cgroupfs_roots and mounts. * All operations which come through kernfs guarantee that the associated cgroup is and stays valid for the duration of operation; however, there are two paths which need to find out the associated cgroup from dentry without going through kernfs - css_tryget_from_dir() and cgroupstats_build(). For these two, kernfs_node->priv is RCU managed so that they can dereference it under RCU read lock. File and directory handling --------------------------- * File and directory operations converted to kernfs_ops and kernfs_syscall_ops. * xattrs is implicitly supported by kernfs. No need to worry about it from cgroup. This means that "xattr" mount option is no longer necessary. A future patch will add a deprecated warning message when sane_behavior. * When cftype->max_write_len > PAGE_SIZE, it's necessary to make a private copy of one of the kernfs_ops to set its atomic_write_len. cftype->kf_ops is added and cgroup_init/exit_cftypes() are updated to handle it. * cftype->lockdep_key added so that kernfs lockdep annotation can be per cftype. * Inidividual file entries and open states are now managed by kernfs. No need to worry about them from cgroup. cfent, cgroup_open_file and their friends are removed. * kernfs_nodes are created deactivated and kernfs_activate() invocations added to places where creation of new nodes are committed. * cgroup_rmdir() uses kernfs_[un]break_active_protection() for self-removal. v2: - Li pointed out in an earlier patch that specifying "name=" during mount without subsystem specification should succeed if there's an existing hierarchy with a matching name although it should fail with -EINVAL if a new hierarchy should be created. Prior to the conversion, this used by handled by deferring failure from NULL return from cgroup_root_from_opts(), which was necessary because root was being created before checking for existing ones. Note that cgroup_root_from_opts() returned an ERR_PTR() value for error conditions which require immediate mount failure. As we now have separate search and creation steps, deferring failure from cgroup_root_from_opts() is no longer necessary. cgroup_root_from_opts() is updated to always return ERR_PTR() value on failure. - The logic to match existing roots is updated so that a mount attempt with a matching name but different subsys_mask are rejected. This was handled by a separate matching loop under the comment "Check for name clashes with existing mounts" but got lost during conversion. Merge the check into the main search loop. - Add __rcu __force casting in RCU_INIT_POINTER() in cgroup_destroy_locked() to avoid the sparse address space warning reported by kbuild test bot. Maybe we want an explicit interface to use kn->priv as RCU protected pointer? v3: Make CONFIG_CGROUPS select CONFIG_KERNFS. v4: Rebased on top of 0ab02ca8f887 ("cgroup: protect modifications to cgroup_idr with cgroup_mutex"). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: kbuild test robot fengguang.wu@intel.com>
2014-02-12 00:52:49 +08:00
select KERNFS
cgroups: make cgroup config a submenu Making CGROUP related configs be a sub-menu. This patch make CGROUP related configs be a sub-menu and makes 1st level configs of "General Setup" shorter. including following additional changes - add help comment about CGROUPS and GROUP_SCHED. - moved MM_OWNER config to the bottom. (for good indent in menuconfig) Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 10:07:30 +08:00
help
cgroups: clean up Kconfig - move CONFIG_PROC_PID_CPUSET into cgroup menu - move MM_OWNER to the bottom for better menu indent - fix typos - use tabs not spaces Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-16 05:50:58 +08:00
This option adds support for grouping sets of processes together, for
cgroups: make cgroup config a submenu Making CGROUP related configs be a sub-menu. This patch make CGROUP related configs be a sub-menu and makes 1st level configs of "General Setup" shorter. including following additional changes - add help comment about CGROUPS and GROUP_SCHED. - moved MM_OWNER config to the bottom. (for good indent in menuconfig) Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 10:07:30 +08:00
use with process control subsystems such as Cpusets, CFS, memory
controls or device isolation.
See
docs: scheduler: convert docs to ReST and rename to *.rst In order to prepare to add them to the Kernel API book, convert the files to ReST format. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-13 01:53:03 +08:00
- Documentation/scheduler/sched-design-CFS.rst (CFS)
docs: cgroup-v1: add it to the admin-guide book Those files belong to the admin guide, so add them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-06-28 00:08:35 +08:00
- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
cgroups: consolidate cgroup documents Move Documentation/cpusets.txt and Documentation/controllers/* to Documentation/cgroups/ Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-16 05:50:59 +08:00
and resource control)
cgroups: make cgroup config a submenu Making CGROUP related configs be a sub-menu. This patch make CGROUP related configs be a sub-menu and makes 1st level configs of "General Setup" shorter. including following additional changes - add help comment about CGROUPS and GROUP_SCHED. - moved MM_OWNER config to the bottom. (for good indent in menuconfig) Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 10:07:30 +08:00
Say N if unsure.
cgroups: clean up Kconfig - move CONFIG_PROC_PID_CPUSET into cgroup menu - move MM_OWNER to the bottom for better menu indent - fix typos - use tabs not spaces Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-16 05:50:58 +08:00
if CGROUPS
mm: memcontrol: lockless page counters Memory is internally accounted in bytes, using spinlock-protected 64-bit counters, even though the smallest accounting delta is a page. The counter interface is also convoluted and does too many things. Introduce a new lockless word-sized page counter API, then change all memory accounting over to it. The translation from and to bytes then only happens when interfacing with userspace. The removed locking overhead is noticable when scaling beyond the per-cpu charge caches - on a 4-socket machine with 144-threads, the following test shows the performance differences of 288 memcgs concurrently running a page fault benchmark: vanilla: 18631648.500498 task-clock (msec) # 140.643 CPUs utilized ( +- 0.33% ) 1,380,638 context-switches # 0.074 K/sec ( +- 0.75% ) 24,390 cpu-migrations # 0.001 K/sec ( +- 8.44% ) 1,843,305,768 page-faults # 0.099 M/sec ( +- 0.00% ) 50,134,994,088,218 cycles # 2.691 GHz ( +- 0.33% ) <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 8,049,712,224,651 instructions # 0.16 insns per cycle ( +- 0.04% ) 1,586,970,584,979 branches # 85.176 M/sec ( +- 0.05% ) 1,724,989,949 branch-misses # 0.11% of all branches ( +- 0.48% ) 132.474343877 seconds time elapsed ( +- 0.21% ) lockless: 12195979.037525 task-clock (msec) # 133.480 CPUs utilized ( +- 0.18% ) 832,850 context-switches # 0.068 K/sec ( +- 0.54% ) 15,624 cpu-migrations # 0.001 K/sec ( +- 10.17% ) 1,843,304,774 page-faults # 0.151 M/sec ( +- 0.00% ) 32,811,216,801,141 cycles # 2.690 GHz ( +- 0.18% ) <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 9,999,265,091,727 instructions # 0.30 insns per cycle ( +- 0.10% ) 2,076,759,325,203 branches # 170.282 M/sec ( +- 0.12% ) 1,656,917,214 branch-misses # 0.08% of all branches ( +- 0.55% ) 91.369330729 seconds time elapsed ( +- 0.45% ) On top of improved scalability, this also gets rid of the icky long long types in the very heart of memcg, which is great for 32 bit and also makes the code a lot more readable. Notable differences between the old and new API: - res_counter_charge() and res_counter_charge_nofail() become page_counter_try_charge() and page_counter_charge() resp. to match the more common kernel naming scheme of try_do()/do() - res_counter_uncharge_until() is only ever used to cancel a local counter and never to uncharge bigger segments of a hierarchy, so it's replaced by the simpler page_counter_cancel() - res_counter_set_limit() is replaced by page_counter_limit(), which expects its callers to serialize against themselves - res_counter_memparse_write_strategy() is replaced by page_counter_limit(), which rounds down to the nearest page size - rather than up. This is more reasonable for explicitely requested hard upper limits. - to keep charging light-weight, page_counter_try_charge() charges speculatively, only to roll back if the result exceeds the limit. Because of this, a failing bigger charge can temporarily lock out smaller charges that would otherwise succeed. The error is bounded to the difference between the smallest and the biggest possible charge size, so for memcg, this means that a failing THP charge can send base page charges into reclaim upto 2MB (4MB) before the limit would have been reached. This should be acceptable. [akpm@linux-foundation.org: add includes for WARN_ON_ONCE and memparse] [akpm@linux-foundation.org: add includes for WARN_ON_ONCE, memparse, strncmp, and PAGE_SIZE] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-11 07:42:31 +08:00
config PAGE_COUNTER
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
bool
mm: memcontrol: lockless page counters Memory is internally accounted in bytes, using spinlock-protected 64-bit counters, even though the smallest accounting delta is a page. The counter interface is also convoluted and does too many things. Introduce a new lockless word-sized page counter API, then change all memory accounting over to it. The translation from and to bytes then only happens when interfacing with userspace. The removed locking overhead is noticable when scaling beyond the per-cpu charge caches - on a 4-socket machine with 144-threads, the following test shows the performance differences of 288 memcgs concurrently running a page fault benchmark: vanilla: 18631648.500498 task-clock (msec) # 140.643 CPUs utilized ( +- 0.33% ) 1,380,638 context-switches # 0.074 K/sec ( +- 0.75% ) 24,390 cpu-migrations # 0.001 K/sec ( +- 8.44% ) 1,843,305,768 page-faults # 0.099 M/sec ( +- 0.00% ) 50,134,994,088,218 cycles # 2.691 GHz ( +- 0.33% ) <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 8,049,712,224,651 instructions # 0.16 insns per cycle ( +- 0.04% ) 1,586,970,584,979 branches # 85.176 M/sec ( +- 0.05% ) 1,724,989,949 branch-misses # 0.11% of all branches ( +- 0.48% ) 132.474343877 seconds time elapsed ( +- 0.21% ) lockless: 12195979.037525 task-clock (msec) # 133.480 CPUs utilized ( +- 0.18% ) 832,850 context-switches # 0.068 K/sec ( +- 0.54% ) 15,624 cpu-migrations # 0.001 K/sec ( +- 10.17% ) 1,843,304,774 page-faults # 0.151 M/sec ( +- 0.00% ) 32,811,216,801,141 cycles # 2.690 GHz ( +- 0.18% ) <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 9,999,265,091,727 instructions # 0.30 insns per cycle ( +- 0.10% ) 2,076,759,325,203 branches # 170.282 M/sec ( +- 0.12% ) 1,656,917,214 branch-misses # 0.08% of all branches ( +- 0.55% ) 91.369330729 seconds time elapsed ( +- 0.45% ) On top of improved scalability, this also gets rid of the icky long long types in the very heart of memcg, which is great for 32 bit and also makes the code a lot more readable. Notable differences between the old and new API: - res_counter_charge() and res_counter_charge_nofail() become page_counter_try_charge() and page_counter_charge() resp. to match the more common kernel naming scheme of try_do()/do() - res_counter_uncharge_until() is only ever used to cancel a local counter and never to uncharge bigger segments of a hierarchy, so it's replaced by the simpler page_counter_cancel() - res_counter_set_limit() is replaced by page_counter_limit(), which expects its callers to serialize against themselves - res_counter_memparse_write_strategy() is replaced by page_counter_limit(), which rounds down to the nearest page size - rather than up. This is more reasonable for explicitely requested hard upper limits. - to keep charging light-weight, page_counter_try_charge() charges speculatively, only to roll back if the result exceeds the limit. Because of this, a failing bigger charge can temporarily lock out smaller charges that would otherwise succeed. The error is bounded to the difference between the smallest and the biggest possible charge size, so for memcg, this means that a failing THP charge can send base page charges into reclaim upto 2MB (4MB) before the limit would have been reached. This should be acceptable. [akpm@linux-foundation.org: add includes for WARN_ON_ONCE and memparse] [akpm@linux-foundation.org: add includes for WARN_ON_ONCE, memparse, strncmp, and PAGE_SIZE] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-11 07:42:31 +08:00
memcg: rename config variables Sanity: CONFIG_CGROUP_MEM_RES_CTLR -> CONFIG_MEMCG CONFIG_CGROUP_MEM_RES_CTLR_SWAP -> CONFIG_MEMCG_SWAP CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED -> CONFIG_MEMCG_SWAP_ENABLED CONFIG_CGROUP_MEM_RES_CTLR_KMEM -> CONFIG_MEMCG_KMEM [mhocko@suse.cz: fix missed bits] Cc: Glauber Costa <glommer@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01 07:43:02 +08:00
config MEMCG
cgroup: clean up the kernel configuration menu nomenclature The config options for the different cgroup controllers use various terms: resource controller, cgroup subsystem, etc. Simplify this to "controller", which is clear enough in the cgroup context. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:56 +08:00
bool "Memory controller"
mm: memcontrol: lockless page counters Memory is internally accounted in bytes, using spinlock-protected 64-bit counters, even though the smallest accounting delta is a page. The counter interface is also convoluted and does too many things. Introduce a new lockless word-sized page counter API, then change all memory accounting over to it. The translation from and to bytes then only happens when interfacing with userspace. The removed locking overhead is noticable when scaling beyond the per-cpu charge caches - on a 4-socket machine with 144-threads, the following test shows the performance differences of 288 memcgs concurrently running a page fault benchmark: vanilla: 18631648.500498 task-clock (msec) # 140.643 CPUs utilized ( +- 0.33% ) 1,380,638 context-switches # 0.074 K/sec ( +- 0.75% ) 24,390 cpu-migrations # 0.001 K/sec ( +- 8.44% ) 1,843,305,768 page-faults # 0.099 M/sec ( +- 0.00% ) 50,134,994,088,218 cycles # 2.691 GHz ( +- 0.33% ) <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 8,049,712,224,651 instructions # 0.16 insns per cycle ( +- 0.04% ) 1,586,970,584,979 branches # 85.176 M/sec ( +- 0.05% ) 1,724,989,949 branch-misses # 0.11% of all branches ( +- 0.48% ) 132.474343877 seconds time elapsed ( +- 0.21% ) lockless: 12195979.037525 task-clock (msec) # 133.480 CPUs utilized ( +- 0.18% ) 832,850 context-switches # 0.068 K/sec ( +- 0.54% ) 15,624 cpu-migrations # 0.001 K/sec ( +- 10.17% ) 1,843,304,774 page-faults # 0.151 M/sec ( +- 0.00% ) 32,811,216,801,141 cycles # 2.690 GHz ( +- 0.18% ) <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 9,999,265,091,727 instructions # 0.30 insns per cycle ( +- 0.10% ) 2,076,759,325,203 branches # 170.282 M/sec ( +- 0.12% ) 1,656,917,214 branch-misses # 0.08% of all branches ( +- 0.55% ) 91.369330729 seconds time elapsed ( +- 0.45% ) On top of improved scalability, this also gets rid of the icky long long types in the very heart of memcg, which is great for 32 bit and also makes the code a lot more readable. Notable differences between the old and new API: - res_counter_charge() and res_counter_charge_nofail() become page_counter_try_charge() and page_counter_charge() resp. to match the more common kernel naming scheme of try_do()/do() - res_counter_uncharge_until() is only ever used to cancel a local counter and never to uncharge bigger segments of a hierarchy, so it's replaced by the simpler page_counter_cancel() - res_counter_set_limit() is replaced by page_counter_limit(), which expects its callers to serialize against themselves - res_counter_memparse_write_strategy() is replaced by page_counter_limit(), which rounds down to the nearest page size - rather than up. This is more reasonable for explicitely requested hard upper limits. - to keep charging light-weight, page_counter_try_charge() charges speculatively, only to roll back if the result exceeds the limit. Because of this, a failing bigger charge can temporarily lock out smaller charges that would otherwise succeed. The error is bounded to the difference between the smallest and the biggest possible charge size, so for memcg, this means that a failing THP charge can send base page charges into reclaim upto 2MB (4MB) before the limit would have been reached. This should be acceptable. [akpm@linux-foundation.org: add includes for WARN_ON_ONCE and memparse] [akpm@linux-foundation.org: add includes for WARN_ON_ONCE, memparse, strncmp, and PAGE_SIZE] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-11 07:42:31 +08:00
select PAGE_COUNTER
cgroup, memcg: move cgroup_event implementation to memcg cgroup_event is way over-designed and tries to build a generic flexible event mechanism into cgroup - fully customizable event specification for each user of the interface. This is utterly unnecessary and overboard especially in the light of the planned unified hierarchy as there's gonna be single agent. Simply generating events at fixed points, or if that's too restrictive, configureable cadence or single set of configureable points should be enough. Thankfully, memcg is the only user and gets to keep it. Replacing it with something simpler on sane_behavior is strongly recommended. This patch moves cgroup_event and "cgroup.event_control" implementation to mm/memcontrol.c. Clearing of events on cgroup destruction is moved from cgroup_destroy_locked() to mem_cgroup_css_offline(), which shouldn't make any noticeable difference. cgroup_css() and __file_cft() are exported to enable the move; however, this will soon be reverted once the event code is updated to be memcg specific. Note that "cgroup.event_control" will now exist only on the hierarchy with memcg attached to it. While this change is visible to userland, it is unlikely to be noticeable as the file has never been meaningful outside memcg. Aside from the above change, this is pure code relocation. v2: Per Li Zefan's comments, init/Kconfig updated accordingly and poll.h inclusion moved from cgroup.c to memcontrol.c. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com>
2013-11-23 07:20:42 +08:00
select EVENTFD
Memory controller: rename to Memory Resource Controller Rename Memory Controller to Memory Resource Controller. Reflect the same changes in the CONFIG definition for the Memory Resource Controller. Group together the config options for Resource Counters and Memory Resource Controller. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-05 06:28:39 +08:00
help
cgroup: clean up the kernel configuration menu nomenclature The config options for the different cgroup controllers use various terms: resource controller, cgroup subsystem, etc. Simplify this to "controller", which is clear enough in the cgroup context. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:56 +08:00
Provides control over the memory footprint of tasks in a cgroup.
Memory controller: rename to Memory Resource Controller Rename Memory Controller to Memory Resource Controller. Reflect the same changes in the CONFIG definition for the Memory Resource Controller. Group together the config options for Resource Counters and Memory Resource Controller. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-05 06:28:39 +08:00
memcg: rename config variables Sanity: CONFIG_CGROUP_MEM_RES_CTLR -> CONFIG_MEMCG CONFIG_CGROUP_MEM_RES_CTLR_SWAP -> CONFIG_MEMCG_SWAP CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED -> CONFIG_MEMCG_SWAP_ENABLED CONFIG_CGROUP_MEM_RES_CTLR_KMEM -> CONFIG_MEMCG_KMEM [mhocko@suse.cz: fix missed bits] Cc: Glauber Costa <glommer@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01 07:43:02 +08:00
config MEMCG_SWAP
mm: memcontrol: make swap tracking an integral part of memory control Without swap page tracking, users that are otherwise memory controlled can easily escape their containment and allocate significant amounts of memory that they're not being charged for. That's because swap does readahead, but without the cgroup records of who owned the page at swapout, readahead pages don't get charged until somebody actually faults them into their page table and we can identify an owner task. This can be maliciously exploited with MADV_WILLNEED, which triggers arbitrary readahead allocations without charging the pages. Make swap swap page tracking an integral part of memcg and remove the Kconfig options. In the first place, it was only made configurable to allow users to save some memory. But the overhead of tracking cgroup ownership per swap page is minimal - 2 byte per page, or 512k per 1G of swap, or 0.04%. Saving that at the expense of broken containment semantics is not something we should present as a coequal option. The swapaccount=0 boot option will continue to exist, and it will eliminate the page_counter overhead and hide the swap control files, but it won't disable swap slot ownership tracking. This patch makes sure we always have the cgroup records at swapin time; the next patch will fix the actual bug by charging readahead swap pages at swapin time rather than at fault time. v2: fix double swap charge bug in cgroup1/cgroup2 code gating [hannes@cmpxchg.org: fix crash with cgroup_disable=memory] Link: http://lkml.kernel.org/r/20200521215855.GB815153@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Roman Gushchin <guro@fb.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Link: http://lkml.kernel.org/r/20200508183105.225460-16-hannes@cmpxchg.org Debugged-by: Hugh Dickins <hughd@google.com> Debugged-by: Michal Hocko <mhocko@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04 07:02:14 +08:00
bool
memcg: rename config variables Sanity: CONFIG_CGROUP_MEM_RES_CTLR -> CONFIG_MEMCG CONFIG_CGROUP_MEM_RES_CTLR_SWAP -> CONFIG_MEMCG_SWAP CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED -> CONFIG_MEMCG_SWAP_ENABLED CONFIG_CGROUP_MEM_RES_CTLR_KMEM -> CONFIG_MEMCG_KMEM [mhocko@suse.cz: fix missed bits] Cc: Glauber Costa <glommer@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01 07:43:02 +08:00
depends on MEMCG && SWAP
cgroups: make swap accounting default behavior configurable Swap accounting can be configured by CONFIG_CGROUP_MEM_RES_CTLR_SWAP configuration option and then it is turned on by default. There is a boot option (noswapaccount) which can disable this feature. This makes it hard for distributors to enable the configuration option as this feature leads to a bigger memory consumption and this is a no-go for general purpose distribution kernel. On the other hand swap accounting may be very usuful for some workloads. This patch adds a new configuration option which controls the default behavior (CGROUP_MEM_RES_CTLR_SWAP_ENABLED). If the option is selected then the feature is turned on by default. It also adds a new boot parameter swapaccount[=1|0] which enhances the original noswapaccount parameter semantic by means of enable/disable logic (defaults to 1 if no value is provided to be still consistent with noswapaccount). The default behavior is unchanged (if CONFIG_CGROUP_MEM_RES_CTLR_SWAP is enabled then CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED is enabled as well) Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-25 04:57:08 +08:00
default y
memcg: mem+swap controller Kconfig Config and control variable for mem+swap controller. This patch adds CONFIG_CGROUP_MEM_RES_CTLR_SWAP (memory resource controller swap extension.) For accounting swap, it's obvious that we have to use additional memory to remember "who uses swap". This adds more overhead. So, it's better to offer "choice" to users. This patch adds 2 choices. This patch adds 2 parameters to enable swap extension or not. - CONFIG - boot option Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 10:07:57 +08:00
mm: introduce CONFIG_MEMCG_KMEM as combination of CONFIG_MEMCG && !CONFIG_SLOB Introduce new config option, which is used to replace repeating CONFIG_MEMCG && !CONFIG_SLOB pattern. Next patches add a little more memcg+kmem related code, so let's keep the defines more clearly. Link: http://lkml.kernel.org/r/153063053670.1818.15013136946600481138.stgit@localhost.localdomain Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Tested-by: Shakeel Butt <shakeelb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Josef Bacik <jbacik@fb.com> Cc: Li RongQing <lirongqing@baidu.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Roman Gushchin <guro@fb.com> Cc: Sahitya Tummala <stummala@codeaurora.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-18 06:47:25 +08:00
config MEMCG_KMEM
bool
depends on MEMCG && !SLOB
default y
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
config BLK_CGROUP
bool "IO controller"
depends on BLOCK
mm/hugetlb: add new HugeTLB cgroup Implement a new controller that allows us to control HugeTLB allocations. The extension allows to limit the HugeTLB usage per control group and enforces the controller limit during page fault. Since HugeTLB doesn't support page reclaim, enforcing the limit at page fault time implies that, the application will get SIGBUS signal if it tries to access HugeTLB pages beyond its limit. This requires the application to know beforehand how much HugeTLB pages it would require for its use. The charge/uncharge calls will be added to HugeTLB code in later patch. Support for cgroup removal will be added in later patches. [akpm@linux-foundation.org: s/CONFIG_CGROUP_HUGETLB_RES_CTLR/CONFIG_MEMCG_HUGETLB/g] [akpm@linux-foundation.org: s/CONFIG_MEMCG_HUGETLB/CONFIG_CGROUP_HUGETLB/g] Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Hillf Danton <dhillf@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01 07:42:12 +08:00
default n
treewide: replace '---help---' in Kconfig files with 'help' Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 00:50:22 +08:00
help
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
Generic block IO controller cgroup interface. This is the common
cgroup interface which should be used by various IO controlling
policies.
mm/hugetlb: add new HugeTLB cgroup Implement a new controller that allows us to control HugeTLB allocations. The extension allows to limit the HugeTLB usage per control group and enforces the controller limit during page fault. Since HugeTLB doesn't support page reclaim, enforcing the limit at page fault time implies that, the application will get SIGBUS signal if it tries to access HugeTLB pages beyond its limit. This requires the application to know beforehand how much HugeTLB pages it would require for its use. The charge/uncharge calls will be added to HugeTLB code in later patch. Support for cgroup removal will be added in later patches. [akpm@linux-foundation.org: s/CONFIG_CGROUP_HUGETLB_RES_CTLR/CONFIG_MEMCG_HUGETLB/g] [akpm@linux-foundation.org: s/CONFIG_MEMCG_HUGETLB/CONFIG_CGROUP_HUGETLB/g] Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Hillf Danton <dhillf@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01 07:42:12 +08:00
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
Currently, CFQ IO scheduler uses it to recognize task groups and
control disk bandwidth allocation (proportional time slice allocation)
to such task groups. It is also used by bio throttling logic in
block layer to implement upper limit in IO rates on a device.
perf: Add cgroup support This kernel patch adds the ability to filter monitoring based on container groups (cgroups). This is for use in per-cpu mode only. The cgroup to monitor is passed as a file descriptor in the pid argument to the syscall. The file descriptor must be opened to the cgroup name in the cgroup filesystem. For instance, if the cgroup name is foo and cgroupfs is mounted in /cgroup, then the file descriptor is opened to /cgroup/foo. Cgroup mode is activated by passing PERF_FLAG_PID_CGROUP in the flags argument to the syscall. For instance to measure in cgroup foo on CPU1 assuming cgroupfs is mounted under /cgroup: struct perf_event_attr attr; int cgroup_fd, fd; cgroup_fd = open("/cgroup/foo", O_RDONLY); fd = perf_event_open(&attr, cgroup_fd, 1, -1, PERF_FLAG_PID_CGROUP); close(cgroup_fd); Signed-off-by: Stephane Eranian <eranian@google.com> [ added perf_cgroup_{exit,attach} ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4d590250.114ddf0a.689e.4482@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-14 17:20:01 +08:00
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
This option only enables generic Block IO controller infrastructure.
One needs to also enable actual IO controlling logic/policy. For
enabling proportional weight division of disk bandwidth in CFQ, set
init/Kconfig: clean up ANON_INODES and old IO schedulers options CONFIG_ANON_INODES is gone since commit 5dd50aaeb185 ("Make anon_inodes unconditional"). CONFIG_CFQ_GROUP_IOSCHED was replaced with CONFIG_BFQ_GROUP_IOSCHED in commit f382fb0bcef4 ("block: remove legacy IO schedulers"). Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: http://lkml.kernel.org/r/20200130192419.3026-1-krzk@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07 11:12:02 +08:00
CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
CONFIG_BLK_DEV_THROTTLING=y.
docs: cgroup-v1: add it to the admin-guide book Those files belong to the admin guide, so add them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-06-28 00:08:35 +08:00
See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
config CGROUP_WRITEBACK
bool
depends on MEMCG && BLK_CGROUP
default y
perf: Add cgroup support This kernel patch adds the ability to filter monitoring based on container groups (cgroups). This is for use in per-cpu mode only. The cgroup to monitor is passed as a file descriptor in the pid argument to the syscall. The file descriptor must be opened to the cgroup name in the cgroup filesystem. For instance, if the cgroup name is foo and cgroupfs is mounted in /cgroup, then the file descriptor is opened to /cgroup/foo. Cgroup mode is activated by passing PERF_FLAG_PID_CGROUP in the flags argument to the syscall. For instance to measure in cgroup foo on CPU1 assuming cgroupfs is mounted under /cgroup: struct perf_event_attr attr; int cgroup_fd, fd; cgroup_fd = open("/cgroup/foo", O_RDONLY); fd = perf_event_open(&attr, cgroup_fd, 1, -1, PERF_FLAG_PID_CGROUP); close(cgroup_fd); Signed-off-by: Stephane Eranian <eranian@google.com> [ added perf_cgroup_{exit,attach} ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4d590250.114ddf0a.689e.4482@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-14 17:20:01 +08:00
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 20:26:18 +08:00
menuconfig CGROUP_SCHED
cgroup: clean up the kernel configuration menu nomenclature The config options for the different cgroup controllers use various terms: resource controller, cgroup subsystem, etc. Simplify this to "controller", which is clear enough in the cgroup context. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:56 +08:00
bool "CPU controller"
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 20:26:18 +08:00
default n
help
This feature lets CPU scheduler recognize task groups and control CPU
bandwidth allocation to such task groups. It uses cgroups to group
tasks.
if CGROUP_SCHED
config FAIR_GROUP_SCHED
bool "Group scheduling for SCHED_OTHER"
depends on CGROUP_SCHED
default CGROUP_SCHED
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-22 00:43:28 +08:00
config CFS_BANDWIDTH
bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
depends on FAIR_GROUP_SCHED
default n
help
This option allows users to define CPU bandwidth rates (limits) for
tasks running within the fair group scheduler. Groups with no limit
set are considered to be unconstrained and will run with no
restriction.
docs: scheduler: convert docs to ReST and rename to *.rst In order to prepare to add them to the Kernel API book, convert the files to ReST format. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-13 01:53:03 +08:00
See Documentation/scheduler/sched-bwc.rst for more information.
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-22 00:43:28 +08:00
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 20:26:18 +08:00
config RT_GROUP_SCHED
bool "Group scheduling for SCHED_RR/FIFO"
depends on CGROUP_SCHED
default n
help
This feature lets you explicitly allocate real CPU bandwidth
sched: Remove remaining USER_SCHED code This is left over from commit 7c9414385e ("sched: Remove USER_SCHED"") Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: David Howells <dhowells@redhat.com> LKML-Reference: <4BA9A05F.7010407@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 13:17:19 +08:00
to task groups. If enabled, it will also make it impossible to
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 20:26:18 +08:00
schedule realtime tasks for non-root users until you allocate
realtime bandwidth for them.
docs: scheduler: convert docs to ReST and rename to *.rst In order to prepare to add them to the Kernel API book, convert the files to ReST format. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-13 01:53:03 +08:00
See Documentation/scheduler/sched-rt-group.rst for more information.
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 20:26:18 +08:00
endif #CGROUP_SCHED
sched/uclamp: Extend CPU's cgroup controller The cgroup CPU bandwidth controller allows to assign a specified (maximum) bandwidth to the tasks of a group. However this bandwidth is defined and enforced only on a temporal base, without considering the actual frequency a CPU is running on. Thus, the amount of computation completed by a task within an allocated bandwidth can be very different depending on the actual frequency the CPU is running that task. The amount of computation can be affected also by the specific CPU a task is running on, especially when running on asymmetric capacity systems like Arm's big.LITTLE. With the availability of schedutil, the scheduler is now able to drive frequency selections based on actual task utilization. Moreover, the utilization clamping support provides a mechanism to bias the frequency selection operated by schedutil depending on constraints assigned to the tasks currently RUNNABLE on a CPU. Giving the mechanisms described above, it is now possible to extend the cpu controller to specify the minimum (or maximum) utilization which should be considered for tasks RUNNABLE on a cpu. This makes it possible to better defined the actual computational power assigned to task groups, thus improving the cgroup CPU bandwidth controller which is currently based just on time constraints. Extend the CPU controller with a couple of new attributes uclamp.{min,max} which allow to enforce utilization boosting and capping for all the tasks in a group. Specifically: - uclamp.min: defines the minimum utilization which should be considered i.e. the RUNNABLE tasks of this group will run at least at a minimum frequency which corresponds to the uclamp.min utilization - uclamp.max: defines the maximum utilization which should be considered i.e. the RUNNABLE tasks of this group will run up to a maximum frequency which corresponds to the uclamp.max utilization These attributes: a) are available only for non-root nodes, both on default and legacy hierarchies, while system wide clamps are defined by a generic interface which does not depends on cgroups. This system wide interface enforces constraints on tasks in the root node. b) enforce effective constraints at each level of the hierarchy which are a restriction of the group requests considering its parent's effective constraints. Root group effective constraints are defined by the system wide interface. This mechanism allows each (non-root) level of the hierarchy to: - request whatever clamp values it would like to get - effectively get only up to the maximum amount allowed by its parent c) have higher priority than task-specific clamps, defined via sched_setattr(), thus allowing to control and restrict task requests. Add two new attributes to the cpu controller to collect "requested" clamp values. Allow that at each non-root level of the hierarchy. Keep it simple by not caring now about "effective" values computation and propagation along the hierarchy. Update sysctl_sched_uclamp_handler() to use the newly introduced uclamp_mutex so that we serialize system default updates with cgroup relate updates. Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Michal Koutny <mkoutny@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Alessio Balsini <balsini@android.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Perret <quentin.perret@arm.com> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Steve Muckle <smuckle@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@google.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: https://lkml.kernel.org/r/20190822132811.31294-2-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-08-22 21:28:06 +08:00
config UCLAMP_TASK_GROUP
bool "Utilization clamping per group of tasks"
depends on CGROUP_SCHED
depends on UCLAMP_TASK
default n
help
This feature enables the scheduler to track the clamped utilization
of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
When this option is enabled, the user can specify a min and max
CPU bandwidth which is allowed for each single task in a group.
The max bandwidth allows to clamp the maximum frequency a task
can use, while the min bandwidth allows to define a minimum
frequency a task will always use.
When task group based utilization clamping is enabled, an eventually
specified task-specific clamp value is constrained by the cgroup
specified clamp value. Both minimum and maximum task clamping cannot
be bigger than the corresponding clamping defined at task group level.
If in doubt, say N.
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
config CGROUP_PIDS
bool "PIDs controller"
help
Provides enforcement of process number limits in the scope of a
cgroup. Any attempt to fork more processes than is allowed in the
cgroup will fail. PIDs are fundamentally a global resource because it
is fairly trivial to reach PID exhaustion before you reach even a
conservative kmemcg limit. As a result, it is possible to grind a
system to halt without being limited by other cgroup policies. The
cgroup: Trivial correction to reflect controller. Trivial correction in menuconfig help to reflect PIDs as controller instead of subsystem to align to rest of the text and documentation. Signed-off-by: Parav Pandit <pandit.parav@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-03-05 14:00:56 +08:00
PIDs controller is designed to stop this from happening.
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
It should be noted that organisational operations (such as attaching
init/Kconfig: fix grammar by moving a closing parenthesis Link: http://lkml.kernel.org/r/20190129150813.15785-1-j.neuschaefer@gmx.net Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-02 06:21:01 +08:00
to a cgroup hierarchy) will *not* be blocked by the PIDs controller,
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
since the PIDs limit only affects a process's ability to fork, not to
attach to a cgroup.
rdmacg: Added rdma cgroup controller Added rdma cgroup controller that does accounting, limit enforcement on rdma/IB resources. Added rdma cgroup header file which defines its APIs to perform charging/uncharging functionality. It also defined APIs for RDMA/IB stack for device registration. Devices which are registered will participate in controller functions of accounting and limit enforcements. It define rdmacg_device structure to bind IB stack and RDMA cgroup controller. RDMA resources are tracked using resource pool. Resource pool is per device, per cgroup entity which allows setting up accounting limits on per device basis. Currently resources are defined by the RDMA cgroup. Resource pool is created/destroyed dynamically whenever charging/uncharging occurs respectively and whenever user configuration is done. Its a tradeoff of memory vs little more code space that creates resource pool object whenever necessary, instead of creating them during cgroup creation and device registration time. Signed-off-by: Parav Pandit <pandit.parav@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-01-10 08:02:13 +08:00
config CGROUP_RDMA
bool "RDMA controller"
help
Provides enforcement of RDMA resources defined by IB stack.
It is fairly easy for consumers to exhaust RDMA resources, which
can result into resource unavailability to other consumers.
RDMA controller is designed to stop this from happening.
Attaching processes with active RDMA resources to the cgroup
hierarchy is allowed even if can cross the hierarchy's limit.
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
config CGROUP_FREEZER
bool "Freezer controller"
help
Provides a way to freeze and unfreeze all tasks in a
cgroup.
mm: memcontrol: introduce CONFIG_MEMCG_LEGACY_KMEM Let the user know that CONFIG_MEMCG_KMEM does not apply to the cgroup2 interface. This also makes legacy-only code sections stand out better. [arnd@arndb.de: mm: memcontrol: only manage socket pressure for CONFIG_INET] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21 07:02:41 +08:00
This option affects the ORIGINAL cgroup interface. The cgroup2 memory
controller includes important in-kernel memory consumers per default.
If you're using cgroup2, say N.
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
config CGROUP_HUGETLB
bool "HugeTLB controller"
depends on HUGETLB_PAGE
select PAGE_COUNTER
blk-cgroup: config options re-arrangement This patch fixes few usability and configurability issues. o All the cgroup based controller options are configurable from "Genral Setup/Control Group Support/" menu. blkio is the only exception. Hence make this option visible in above menu and make it configurable from there to bring it inline with rest of the cgroup based controllers. o Get rid of CONFIG_DEBUG_CFQ_IOSCHED. This option currently does two things. - Enable printing of cgroup paths in blktrace - Enables CONFIG_DEBUG_BLK_CGROUP, which in turn displays additional stat files in cgroup. If we are using group scheduling, blktrace data is of not really much use if cgroup information is not present. To get this data, currently one has to also enable CONFIG_DEBUG_CFQ_IOSCHED, which in turn brings the overhead of all the additional debug stat files which is not desired. Hence, this patch moves printing of cgroup paths under CONFIG_CFQ_GROUP_IOSCHED. This allows us to get rid of CONFIG_DEBUG_CFQ_IOSCHED completely. Now all the debug stat files are controlled only by CONFIG_DEBUG_BLK_CGROUP which can be enabled through config menu. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Divyesh Shah <dpshah@google.com> Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-27 01:27:56 +08:00
default n
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
help
Provides a cgroup controller for HugeTLB pages.
When you enable this, you can put a per cgroup limit on HugeTLB usage.
The limit is enforced during page fault. Since HugeTLB doesn't
support page reclaim, enforcing the limit at page fault time implies
that, the application will get SIGBUS signal if it tries to access
HugeTLB pages beyond its limit. This requires the application to know
beforehand how much HugeTLB pages it would require for its use. The
control group is tracked in the third page lru pointer. This means
that we cannot use the controller with huge page less than 3 pages.
blk-cgroup: config options re-arrangement This patch fixes few usability and configurability issues. o All the cgroup based controller options are configurable from "Genral Setup/Control Group Support/" menu. blkio is the only exception. Hence make this option visible in above menu and make it configurable from there to bring it inline with rest of the cgroup based controllers. o Get rid of CONFIG_DEBUG_CFQ_IOSCHED. This option currently does two things. - Enable printing of cgroup paths in blktrace - Enables CONFIG_DEBUG_BLK_CGROUP, which in turn displays additional stat files in cgroup. If we are using group scheduling, blktrace data is of not really much use if cgroup information is not present. To get this data, currently one has to also enable CONFIG_DEBUG_CFQ_IOSCHED, which in turn brings the overhead of all the additional debug stat files which is not desired. Hence, this patch moves printing of cgroup paths under CONFIG_CFQ_GROUP_IOSCHED. This allows us to get rid of CONFIG_DEBUG_CFQ_IOSCHED completely. Now all the debug stat files are controlled only by CONFIG_DEBUG_BLK_CGROUP which can be enabled through config menu. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Divyesh Shah <dpshah@google.com> Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-27 01:27:56 +08:00
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
config CPUSETS
bool "Cpuset controller"
sched/cpuset: Only offer CONFIG_CPUSETS if SMP is enabled Make CONFIG_CPUSETS=y depend on SMP as this feature makes no sense on UP. This allows for configuring out cpuset_cpumask_can_shrink() and task_can_attach() entirely, which shrinks the kernel a bit. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170614171926.8345-2-nicolas.pitre@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-15 01:19:23 +08:00
depends on SMP
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
help
This option will let you create and manage CPUSETs which
allow dynamically partitioning a system into sets of CPUs and
Memory Nodes and assigning tasks to run only within those sets.
This is primarily useful on large SMP or NUMA systems.
blk-cgroup: config options re-arrangement This patch fixes few usability and configurability issues. o All the cgroup based controller options are configurable from "Genral Setup/Control Group Support/" menu. blkio is the only exception. Hence make this option visible in above menu and make it configurable from there to bring it inline with rest of the cgroup based controllers. o Get rid of CONFIG_DEBUG_CFQ_IOSCHED. This option currently does two things. - Enable printing of cgroup paths in blktrace - Enables CONFIG_DEBUG_BLK_CGROUP, which in turn displays additional stat files in cgroup. If we are using group scheduling, blktrace data is of not really much use if cgroup information is not present. To get this data, currently one has to also enable CONFIG_DEBUG_CFQ_IOSCHED, which in turn brings the overhead of all the additional debug stat files which is not desired. Hence, this patch moves printing of cgroup paths under CONFIG_CFQ_GROUP_IOSCHED. This allows us to get rid of CONFIG_DEBUG_CFQ_IOSCHED completely. Now all the debug stat files are controlled only by CONFIG_DEBUG_BLK_CGROUP which can be enabled through config menu. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Divyesh Shah <dpshah@google.com> Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-27 01:27:56 +08:00
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
Say N if unsure.
blk-cgroup: config options re-arrangement This patch fixes few usability and configurability issues. o All the cgroup based controller options are configurable from "Genral Setup/Control Group Support/" menu. blkio is the only exception. Hence make this option visible in above menu and make it configurable from there to bring it inline with rest of the cgroup based controllers. o Get rid of CONFIG_DEBUG_CFQ_IOSCHED. This option currently does two things. - Enable printing of cgroup paths in blktrace - Enables CONFIG_DEBUG_BLK_CGROUP, which in turn displays additional stat files in cgroup. If we are using group scheduling, blktrace data is of not really much use if cgroup information is not present. To get this data, currently one has to also enable CONFIG_DEBUG_CFQ_IOSCHED, which in turn brings the overhead of all the additional debug stat files which is not desired. Hence, this patch moves printing of cgroup paths under CONFIG_CFQ_GROUP_IOSCHED. This allows us to get rid of CONFIG_DEBUG_CFQ_IOSCHED completely. Now all the debug stat files are controlled only by CONFIG_DEBUG_BLK_CGROUP which can be enabled through config menu. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Divyesh Shah <dpshah@google.com> Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-27 01:27:56 +08:00
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
config PROC_PID_CPUSET
bool "Include legacy /proc/<pid>/cpuset file"
depends on CPUSETS
default y
blk-cgroup: config options re-arrangement This patch fixes few usability and configurability issues. o All the cgroup based controller options are configurable from "Genral Setup/Control Group Support/" menu. blkio is the only exception. Hence make this option visible in above menu and make it configurable from there to bring it inline with rest of the cgroup based controllers. o Get rid of CONFIG_DEBUG_CFQ_IOSCHED. This option currently does two things. - Enable printing of cgroup paths in blktrace - Enables CONFIG_DEBUG_BLK_CGROUP, which in turn displays additional stat files in cgroup. If we are using group scheduling, blktrace data is of not really much use if cgroup information is not present. To get this data, currently one has to also enable CONFIG_DEBUG_CFQ_IOSCHED, which in turn brings the overhead of all the additional debug stat files which is not desired. Hence, this patch moves printing of cgroup paths under CONFIG_CFQ_GROUP_IOSCHED. This allows us to get rid of CONFIG_DEBUG_CFQ_IOSCHED completely. Now all the debug stat files are controlled only by CONFIG_DEBUG_BLK_CGROUP which can be enabled through config menu. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Divyesh Shah <dpshah@google.com> Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-27 01:27:56 +08:00
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
config CGROUP_DEVICE
bool "Device controller"
help
Provides a cgroup controller implementing whitelists for
devices which a process in the cgroup can mknod or open.
config CGROUP_CPUACCT
bool "Simple CPU accounting controller"
help
Provides a simple controller for monitoring the
total CPU consumed by the tasks in a cgroup.
config CGROUP_PERF
bool "Perf controller"
depends on PERF_EVENTS
help
This option extends the perf per-cpu mode to restrict monitoring
to threads which belong to the cgroup specified and run on the
perf/core: Add PERF_SAMPLE_CGROUP feature The PERF_SAMPLE_CGROUP bit is to save (perf_event) cgroup information in the sample. It will add a 64-bit id to identify current cgroup and it's the file handle in the cgroup file system. Userspace should use this information with PERF_RECORD_CGROUP event to match which cgroup it belongs. I put it before PERF_SAMPLE_AUX for simplicity since it just needs a 64-bit word. But if we want bigger samples, I can work on that direction too. Committer testing: $ pahole perf_sample_data | grep -w cgroup -B5 -A5 /* --- cacheline 4 boundary (256 bytes) was 56 bytes ago --- */ struct perf_regs regs_intr; /* 312 16 */ /* --- cacheline 5 boundary (320 bytes) was 8 bytes ago --- */ u64 stack_user_size; /* 328 8 */ u64 phys_addr; /* 336 8 */ u64 cgroup; /* 344 8 */ /* size: 384, cachelines: 6, members: 22 */ /* padding: 32 */ }; $ Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lore.kernel.org/lkml/20200325124536.2800725-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-03-25 20:45:29 +08:00
designated cpu. Or this can be used to have cgroup ID in samples
so that it can monitor performance events among cgroups.
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
Say N if unsure.
cgroup: add support for eBPF programs This patch adds two sets of eBPF program pointers to struct cgroup. One for such that are directly pinned to a cgroup, and one for such that are effective for it. To illustrate the logic behind that, assume the following example cgroup hierarchy. A - B - C \ D - E If only B has a program attached, it will be effective for B, C, D and E. If D then attaches a program itself, that will be effective for both D and E, and the program in B will only affect B and C. Only one program of a given type is effective for a cgroup. Attaching and detaching programs will be done through the bpf(2) syscall. For now, ingress and egress inet socket filtering are the only supported use-cases. Signed-off-by: Daniel Mack <daniel@zonque.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-23 23:52:26 +08:00
config CGROUP_BPF
bool "Support for eBPF programs attached to cgroups"
cgroup: Fix CGROUP_BPF config CGROUP_BPF depended on SOCK_CGROUP_DATA which can't be manually enabled, making it rather challenging to turn CGROUP_BPF on. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-17 00:33:45 +08:00
depends on BPF_SYSCALL
select SOCK_CGROUP_DATA
cgroup: add support for eBPF programs This patch adds two sets of eBPF program pointers to struct cgroup. One for such that are directly pinned to a cgroup, and one for such that are effective for it. To illustrate the logic behind that, assume the following example cgroup hierarchy. A - B - C \ D - E If only B has a program attached, it will be effective for B, C, D and E. If D then attaches a program itself, that will be effective for both D and E, and the program in B will only affect B and C. Only one program of a given type is effective for a cgroup. Attaching and detaching programs will be done through the bpf(2) syscall. For now, ingress and egress inet socket filtering are the only supported use-cases. Signed-off-by: Daniel Mack <daniel@zonque.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-23 23:52:26 +08:00
help
Allow attaching eBPF programs to a cgroup using the bpf(2)
syscall command BPF_PROG_ATTACH.
In which context these programs are accessed depends on the type
of attachment. For instance, programs that are attached using
BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
inet sockets.
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
config CGROUP_DEBUG
cgroup: Make Kconfig prompt of debug cgroup more accurate The Kconfig prompt and description of the debug cgroup controller more accurate by saying that it is for debug purpose only and its interfaces are unstable. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-06-14 05:18:03 +08:00
bool "Debug controller"
blk-cgroup: config options re-arrangement This patch fixes few usability and configurability issues. o All the cgroup based controller options are configurable from "Genral Setup/Control Group Support/" menu. blkio is the only exception. Hence make this option visible in above menu and make it configurable from there to bring it inline with rest of the cgroup based controllers. o Get rid of CONFIG_DEBUG_CFQ_IOSCHED. This option currently does two things. - Enable printing of cgroup paths in blktrace - Enables CONFIG_DEBUG_BLK_CGROUP, which in turn displays additional stat files in cgroup. If we are using group scheduling, blktrace data is of not really much use if cgroup information is not present. To get this data, currently one has to also enable CONFIG_DEBUG_CFQ_IOSCHED, which in turn brings the overhead of all the additional debug stat files which is not desired. Hence, this patch moves printing of cgroup paths under CONFIG_CFQ_GROUP_IOSCHED. This allows us to get rid of CONFIG_DEBUG_CFQ_IOSCHED completely. Now all the debug stat files are controlled only by CONFIG_DEBUG_BLK_CGROUP which can be enabled through config menu. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Divyesh Shah <dpshah@google.com> Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-27 01:27:56 +08:00
default n
cgroup: Make Kconfig prompt of debug cgroup more accurate The Kconfig prompt and description of the debug cgroup controller more accurate by saying that it is for debug purpose only and its interfaces are unstable. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-06-14 05:18:03 +08:00
depends on DEBUG_KERNEL
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
help
This option enables a simple controller that exports
cgroup: Make Kconfig prompt of debug cgroup more accurate The Kconfig prompt and description of the debug cgroup controller more accurate by saying that it is for debug purpose only and its interfaces are unstable. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-06-14 05:18:03 +08:00
debugging information about the cgroups framework. This
controller is for control cgroup debugging only. Its
interfaces are not stable.
blk-cgroup: config options re-arrangement This patch fixes few usability and configurability issues. o All the cgroup based controller options are configurable from "Genral Setup/Control Group Support/" menu. blkio is the only exception. Hence make this option visible in above menu and make it configurable from there to bring it inline with rest of the cgroup based controllers. o Get rid of CONFIG_DEBUG_CFQ_IOSCHED. This option currently does two things. - Enable printing of cgroup paths in blktrace - Enables CONFIG_DEBUG_BLK_CGROUP, which in turn displays additional stat files in cgroup. If we are using group scheduling, blktrace data is of not really much use if cgroup information is not present. To get this data, currently one has to also enable CONFIG_DEBUG_CFQ_IOSCHED, which in turn brings the overhead of all the additional debug stat files which is not desired. Hence, this patch moves printing of cgroup paths under CONFIG_CFQ_GROUP_IOSCHED. This allows us to get rid of CONFIG_DEBUG_CFQ_IOSCHED completely. Now all the debug stat files are controlled only by CONFIG_DEBUG_BLK_CGROUP which can be enabled through config menu. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Divyesh Shah <dpshah@google.com> Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-27 01:27:56 +08:00
cgroup: put controller Kconfig options in meaningful order To make it easier to quickly find what's needed list the basic resource controllers of cgroup2 first - io, memory, cpu - while pushing the more exotic and/or legacy controllers to the bottom. tj: Removed spurious "&& CGROUPS" from CGROUP_PERF as suggested by Li. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-12-18 06:19:57 +08:00
Say N.
writeback: add {CONFIG|BDI_CAP|FS}_CGROUP_WRITEBACK cgroup writeback requires support from both bdi and filesystem sides. Add BDI_CAP_CGROUP_WRITEBACK and FS_CGROUP_WRITEBACK to indicate support and enable BDI_CAP_CGROUP_WRITEBACK on block based bdi's by default. Also, define CONFIG_CGROUP_WRITEBACK which is enabled if both MEMCG and BLK_CGROUP are enabled. inode_cgwb_enabled() which determines whether a given inode's both bdi and fs support cgroup writeback is added. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-23 05:13:36 +08:00
cgroup: move CONFIG_SOCK_CGROUP_DATA to init/Kconfig We now 'select SOCK_CGROUP_DATA' but Kconfig complains that this is not right when CONFIG_NET is disabled and there is no socket interface: warning: (CGROUP_BPF) selects SOCK_CGROUP_DATA which has unmet direct dependencies (NET) I don't know what the correct solution for this is, but simply removing the dependency on NET from SOCK_CGROUP_DATA by moving it out of the 'if NET' section avoids the warning and does not produce other build errors. Fixes: 483c4933ea09 ("cgroup: Fix CGROUP_BPF config") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-10 20:08:06 +08:00
config SOCK_CGROUP_DATA
bool
default n
cgroups: clean up Kconfig - move CONFIG_PROC_PID_CPUSET into cgroup menu - move MM_OWNER to the bottom for better menu indent - fix typos - use tabs not spaces Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-16 05:50:58 +08:00
endif # CGROUPS
memcg: mem+swap controller Kconfig Config and control variable for mem+swap controller. This patch adds CONFIG_CGROUP_MEM_RES_CTLR_SWAP (memory resource controller swap extension.) For accounting swap, it's obvious that we have to use additional memory to remember "who uses swap". This adds more overhead. So, it's better to offer "choice" to users. This patch adds 2 choices. This patch adds 2 parameters to enable swap extension or not. - CONFIG - boot option Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 10:07:57 +08:00
namespaces Kconfig: make namespace a submenu Make the namespaces config option a submenu. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:38 +08:00
menuconfig NAMESPACES
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Namespaces support" if EXPERT
kernel: conditionally support non-root users, groups and capabilities There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-16 07:16:41 +08:00
depends on MULTIUSER
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
default !EXPERT
namespaces: add the NAMESPACES config option The option is selectable if EMBEDDED is chosen only. When the EMBEDDED is off namespaces will be on. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:19 +08:00
help
Provides the way to make tasks work with different objects using
the same id. For example same IPC id may refer to different objects
or same user id or pid may refer to different tasks when used in
different namespaces.
namespaces Kconfig: make namespace a submenu Make the namespaces config option a submenu. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:38 +08:00
if NAMESPACES
namespaces: move the UTS namespace under UTS_NS option Currently all the namespace management code is in the kernel/utsname.c file, so just compile it out and make stubs in the appropriate header. The init namespace itself is in init/version.c and is in the kernel all the time. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:21 +08:00
config UTS_NS
bool "UTS namespace"
namespaces: default all the namespaces to 'yes' when CONFIG_NAMESPACES is selected As the different namespaces depend on 'CONFIG_NAMESPACES', it is logical to enable all the namespaces when we enable NAMESPACES. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: David Miller <davem@davemloft.net> Acked-By: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:37 +08:00
default y
namespaces: move the UTS namespace under UTS_NS option Currently all the namespace management code is in the kernel/utsname.c file, so just compile it out and make stubs in the appropriate header. The init namespace itself is in init/version.c and is in the kernel all the time. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:21 +08:00
help
In this namespace tasks see different info provided with the
uname() system call
ns: Introduce Time Namespace Time Namespace isolates clock values. The kernel provides access to several clocks CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc. CLOCK_REALTIME System-wide clock that measures real (i.e., wall-clock) time. CLOCK_MONOTONIC Clock that cannot be set and represents monotonic time since some unspecified starting point. CLOCK_BOOTTIME Identical to CLOCK_MONOTONIC, except it also includes any time that the system is suspended. For many users, the time namespace means the ability to changes date and time in a container (CLOCK_REALTIME). Providing per namespace notions of CLOCK_REALTIME would be complex with a massive overhead, but has a dubious value. But in the context of checkpoint/restore functionality, monotonic and boottime clocks become interesting. Both clocks are monotonic with unspecified starting points. These clocks are widely used to measure time slices and set timers. After restoring or migrating processes, it has to be guaranteed that they never go backward. In an ideal case, the behavior of these clocks should be the same as for a case when a whole system is suspended. All this means that it is required to set CLOCK_MONOTONIC and CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace offsets for clocks. A time namespace is similar to a pid namespace in the way how it is created: unshare(CLONE_NEWTIME) system call creates a new time namespace, but doesn't set it to the current process. Then all children of the process will be born in the new time namespace, or a process can use the setns() system call to join a namespace. This scheme allows setting clock offsets for a namespace, before any processes appear in it. All available clone flags have been used, so CLONE_NEWTIME uses the highest bit of CSIGNAL. It means that it can be used only with the unshare() and the clone3() system calls. [ tglx: Adjusted paragraph about clone3() to reality and massaged the changelog a bit. ] Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://criu.org/Time_namespace Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
config TIME_NS
bool "TIME namespace"
lib/vdso: Prepare for time namespace support To support time namespaces in the vdso with a minimal impact on regular non time namespace affected tasks, the namespace handling needs to be hidden in a slow path. The most obvious place is vdso_seq_begin(). If a task belongs to a time namespace then the VVAR page which contains the system wide vdso data is replaced with a namespace specific page which has the same layout as the VVAR page. That page has vdso_data->seq set to 1 to enforce the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace handling path. The extra check in the case that vdso_data->seq is odd, e.g. a concurrent update of the vdso data is in progress, is not really affecting regular tasks which are not part of a time namespace as the task is spin waiting for the update to finish and vdso_data->seq to become even again. If a time namespace task hits that code path, it invokes the corresponding time getter function which retrieves the real VVAR page, reads host time and then adds the offset for the requested clock which is stored in the special VVAR page. If VDSO time namespace support is disabled the whole magic is compiled out. Initial testing shows that the disabled case is almost identical to the host case which does not take the slow timens path. With the special timens page installed the performance hit is constant time and in the range of 5-7%. For the vdso functions which are not using the sequence count an unconditional check for vdso_data->clock_mode is added which switches to the real vdso when the clock_mode is VCLOCK_TIMENS. [avagin: Make do_hres_timens() work with raw clocks too: choose vdso_data pointer by CS_RAW offset.] Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-21-dima@arista.com
2019-11-12 09:27:09 +08:00
depends on GENERIC_VDSO_TIME_NS
ns: Introduce Time Namespace Time Namespace isolates clock values. The kernel provides access to several clocks CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc. CLOCK_REALTIME System-wide clock that measures real (i.e., wall-clock) time. CLOCK_MONOTONIC Clock that cannot be set and represents monotonic time since some unspecified starting point. CLOCK_BOOTTIME Identical to CLOCK_MONOTONIC, except it also includes any time that the system is suspended. For many users, the time namespace means the ability to changes date and time in a container (CLOCK_REALTIME). Providing per namespace notions of CLOCK_REALTIME would be complex with a massive overhead, but has a dubious value. But in the context of checkpoint/restore functionality, monotonic and boottime clocks become interesting. Both clocks are monotonic with unspecified starting points. These clocks are widely used to measure time slices and set timers. After restoring or migrating processes, it has to be guaranteed that they never go backward. In an ideal case, the behavior of these clocks should be the same as for a case when a whole system is suspended. All this means that it is required to set CLOCK_MONOTONIC and CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace offsets for clocks. A time namespace is similar to a pid namespace in the way how it is created: unshare(CLONE_NEWTIME) system call creates a new time namespace, but doesn't set it to the current process. Then all children of the process will be born in the new time namespace, or a process can use the setns() system call to join a namespace. This scheme allows setting clock offsets for a namespace, before any processes appear in it. All available clone flags have been used, so CLONE_NEWTIME uses the highest bit of CSIGNAL. It means that it can be used only with the unshare() and the clone3() system calls. [ tglx: Adjusted paragraph about clone3() to reality and massaged the changelog a bit. ] Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://criu.org/Time_namespace Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
default y
help
In this namespace boottime and monotonic clocks can be set.
The time will keep going with the same pace.
namespaces: move the IPC namespace under IPC_NS option Currently the IPC namespace management code is spread over the ipc/*.c files. I moved this code into ipc/namespace.c file which is compiled out when needed. The linux/ipc_namespace.h file is used to store the prototypes of the functions in namespace.c and the stubs for NAMESPACES=n case. This is done so, because the stub for copy_ipc_namespace requires the knowledge of the CLONE_NEWIPC flag, which is in sched.h. But the linux/ipc.h file itself in included into many many .c files via the sys.h->sem.h sequence so adding the sched.h into it will make all these .c depend on sched.h which is not that good. On the other hand the knowledge about the namespaces stuff is required in 4 .c files only. Besides, this patch compiles out some auxiliary functions from ipc/sem.c, msg.c and shm.c files. It turned out that moving these functions into namespaces.c is not that easy because they use many other calls and macros from the original file. Moving them would make this patch complicated. On the other hand all these functions can be consolidated, so I will send a separate patch doing this a bit later. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:22 +08:00
config IPC_NS
bool "IPC namespace"
namespaces Kconfig: make namespace a submenu Make the namespaces config option a submenu. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:38 +08:00
depends on (SYSVIPC || POSIX_MQUEUE)
namespaces: default all the namespaces to 'yes' when CONFIG_NAMESPACES is selected As the different namespaces depend on 'CONFIG_NAMESPACES', it is logical to enable all the namespaces when we enable NAMESPACES. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: David Miller <davem@davemloft.net> Acked-By: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:37 +08:00
default y
namespaces: move the IPC namespace under IPC_NS option Currently the IPC namespace management code is spread over the ipc/*.c files. I moved this code into ipc/namespace.c file which is compiled out when needed. The linux/ipc_namespace.h file is used to store the prototypes of the functions in namespace.c and the stubs for NAMESPACES=n case. This is done so, because the stub for copy_ipc_namespace requires the knowledge of the CLONE_NEWIPC flag, which is in sched.h. But the linux/ipc.h file itself in included into many many .c files via the sys.h->sem.h sequence so adding the sched.h into it will make all these .c depend on sched.h which is not that good. On the other hand the knowledge about the namespaces stuff is required in 4 .c files only. Besides, this patch compiles out some auxiliary functions from ipc/sem.c, msg.c and shm.c files. It turned out that moving these functions into namespaces.c is not that easy because they use many other calls and macros from the original file. Moving them would make this patch complicated. On the other hand all these functions can be consolidated, so I will send a separate patch doing this a bit later. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:22 +08:00
help
In this namespace tasks work with IPC ids which correspond to
namespaces: mqueue ns: move mqueue_mnt into struct ipc_namespace Move mqueue vfsmount plus a few tunables into the ipc_namespace struct. The CONFIG_IPC_NS boolean and the ipc_namespace struct will serve both the posix message queue namespaces and the SYSV ipc namespaces. The sysctl code will be fixed separately in patch 3. After just this patch, making a change to posix mqueue tunables always changes the values in the initial ipc namespace. Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07 10:01:08 +08:00
different IPC objects in different namespaces.
namespaces: move the IPC namespace under IPC_NS option Currently the IPC namespace management code is spread over the ipc/*.c files. I moved this code into ipc/namespace.c file which is compiled out when needed. The linux/ipc_namespace.h file is used to store the prototypes of the functions in namespace.c and the stubs for NAMESPACES=n case. This is done so, because the stub for copy_ipc_namespace requires the knowledge of the CLONE_NEWIPC flag, which is in sched.h. But the linux/ipc.h file itself in included into many many .c files via the sys.h->sem.h sequence so adding the sched.h into it will make all these .c depend on sched.h which is not that good. On the other hand the knowledge about the namespaces stuff is required in 4 .c files only. Besides, this patch compiles out some auxiliary functions from ipc/sem.c, msg.c and shm.c files. It turned out that moving these functions into namespaces.c is not that easy because they use many other calls and macros from the original file. Moving them would make this patch complicated. On the other hand all these functions can be consolidated, so I will send a separate patch doing this a bit later. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:22 +08:00
namespaces: cleanup the code managed with the USER_NS option Make the user_namespace.o compilation depend on this option and move the init_user_ns into user.c file to make the kernel compile and work without the namespaces support. This make the user namespace code be organized similar to other namespaces'. Also mask the USER_NS option as "depend on NAMESPACES". [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:23 +08:00
config USER_NS
init: remove depends on CONFIG_EXPERIMENTAL The CONFIG_EXPERIMENTAL config item has not carried much meaning for a while now and is almost always enabled by default. As agreed during the Linux kernel summit, remove it from any "depends on" lines in Kconfigs. CC: "Eric W. Biederman" <ebiederm@xmission.com> CC: Serge Hallyn <serge.hallyn@canonical.com> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2012-10-03 02:19:29 +08:00
bool "User namespace"
userns: Add a Kconfig option to enforce strict kuid and kgid type checks Make it possible to easily switch between strong mandatory type checks and relaxed type checks so that the code can easily be tested with the type checks and then built with the strong type checks disabled so the resulting code can be used. Require strong mandatory type checks when enabling the user namespace. It is very simple to make a typo and use the wrong type allowing conversions to/from userspace values to be bypassed by accident, the strong type checks prevent this. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-11-18 02:23:55 +08:00
default n
namespaces: cleanup the code managed with the USER_NS option Make the user_namespace.o compilation depend on this option and move the init_user_ns into user.c file to make the kernel compile and work without the namespaces support. This make the user namespace code be organized similar to other namespaces'. Also mask the USER_NS option as "depend on NAMESPACES". [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:23 +08:00
help
This allows containers, i.e. vservers, to use user namespaces
to provide different user info for different servers.
userns: Recommend use of memory control groups. In the help text describing user namespaces recommend use of memory control groups. In many cases memory control groups are the only mechanism there is to limit how much memory a user who can create user namespaces can use. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2013-01-26 08:48:31 +08:00
When user namespaces are enabled in the kernel it is
mm: memcontrol: rein in the CONFIG space madness What CONFIG_INET and CONFIG_LEGACY_KMEM guard inside the memory controller code is insignificant, having these conditionals is not worth the complication and fragility that comes with them. [akpm@linux-foundation.org: rework mem_cgroup_css_free() statement ordering] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21 07:02:47 +08:00
recommended that the MEMCG option also be enabled and that
user-space use the memory control groups to limit the amount
of memory a memory unprivileged users can use.
userns: Recommend use of memory control groups. In the help text describing user namespaces recommend use of memory control groups. In many cases memory control groups are the only mechanism there is to limit how much memory a user who can create user namespaces can use. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2013-01-26 08:48:31 +08:00
namespaces: cleanup the code managed with the USER_NS option Make the user_namespace.o compilation depend on this option and move the init_user_ns into user.c file to make the kernel compile and work without the namespaces support. This make the user namespace code be organized similar to other namespaces'. Also mask the USER_NS option as "depend on NAMESPACES". [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:23 +08:00
If unsure, say N.
namespaces: cleanup the code managed with PID_NS option Just like with the user namespaces, move the namespace management code into the separate .c file and mark the (already existing) PID_NS option as "depend on NAMESPACES" [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:24 +08:00
config PID_NS
namespaces: remove pid_ns and net_ns experimental status The pid namespace is in the kernel since 2.6.27 and the net_ns since 2.6.29. They are enabled in the distro by default and used by userspace component. They are mature enough to remove the 'experimental' label. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:37 +08:00
bool "PID Namespaces"
namespaces: default all the namespaces to 'yes' when CONFIG_NAMESPACES is selected As the different namespaces depend on 'CONFIG_NAMESPACES', it is logical to enable all the namespaces when we enable NAMESPACES. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: David Miller <davem@davemloft.net> Acked-By: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:37 +08:00
default y
namespaces: cleanup the code managed with PID_NS option Just like with the user namespaces, move the namespace management code into the separate .c file and mark the (already existing) PID_NS option as "depend on NAMESPACES" [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:24 +08:00
help
kconfig: fix typos: "Suport" -> "Support" Signed-off-by: Heikki Orsila <heikki.orsila@iki.fi> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-07-06 20:48:02 +08:00
Support process id namespaces. This allows having multiple
trivial: fix typos/grammar errors in Kconfig texts Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-01-26 18:12:25 +08:00
processes with the same pid as long as they are in different
namespaces: cleanup the code managed with PID_NS option Just like with the user namespaces, move the namespace management code into the separate .c file and mark the (already existing) PID_NS option as "depend on NAMESPACES" [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:18:24 +08:00
pid namespaces. This is a building block of containers.
net: Move config NET_NS to from net/Kconfig to init/Kconfig Make NET_NS available underneath the generic Namespaces config option since all of the other namespace options are there. Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-27 04:25:55 +08:00
config NET_NS
bool "Network namespace"
namespaces Kconfig: make namespace a submenu Make the namespaces config option a submenu. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:38 +08:00
depends on NET
namespaces: default all the namespaces to 'yes' when CONFIG_NAMESPACES is selected As the different namespaces depend on 'CONFIG_NAMESPACES', it is logical to enable all the namespaces when we enable NAMESPACES. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: David Miller <davem@davemloft.net> Acked-By: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:37 +08:00
default y
net: Move config NET_NS to from net/Kconfig to init/Kconfig Make NET_NS available underneath the generic Namespaces config option since all of the other namespace options are there. Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-27 04:25:55 +08:00
help
Allow user space to create what appear to be multiple instances
of the network stack.
namespaces Kconfig: make namespace a submenu Make the namespaces config option a submenu. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:38 +08:00
endif # NAMESPACES
init/Kconfig: remove EXPERT from CHECKPOINT_RESTORE The CHECKPOINT_RESTORE configuration option was introduced in 2012 and combined with EXPERT. CHECKPOINT_RESTORE is already enabled in many distribution kernels and also part of the defconfigs of various architectures. To make it easier for distributions to enable CHECKPOINT_RESTORE this removes EXPERT and moves the configuration option out of the EXPERT block. Link: http://lkml.kernel.org/r/20180712130733.11510-1-adrian@lisas.de Signed-off-by: Adrian Reber <adrian@lisas.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Acked-by: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 13:01:17 +08:00
config CHECKPOINT_RESTORE
bool "Checkpoint/restore support"
select PROC_CHILDREN
default n
help
Enables additional kernel features in a sake of checkpoint/restore.
In particular it adds auxiliary prctl codes to setup process text,
data and heap segment sizes, and a few additional /proc filesystem
entries.
If unsure, say N here.
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 21:18:03 +08:00
config SCHED_AUTOGROUP
bool "Automatic process group scheduling"
select CGROUPS
select CGROUP_SCHED
select FAIR_GROUP_SCHED
help
This option optimizes the scheduler for common desktop workloads by
automatically creating and populating task groups. This separation
of workloads isolates aggressive CPU burners (like build jobs) from
desktop applications. Task group autogeneration is currently based
upon task session.
namespaces Kconfig: move namespace menu location after the cgroup We have the namespaces as a menuconfig like the cgroup. The cgroup and the namespace are two base bricks for the containers. It is more logical to put the namespace menu right after the cgroup menu. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:41 +08:00
config SYSFS_DEPRECATED
sysfs: Capitalize description of SYSFS_DEPRECATED{_V2} options Signed-off-by: Ferenc Wagner <wferi@niif.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-11 02:04:22 +08:00
bool "Enable deprecated sysfs features to support old userspace tools"
namespaces Kconfig: move namespace menu location after the cgroup We have the namespaces as a menuconfig like the cgroup. The cgroup and the namespace are two base bricks for the containers. It is more logical to put the namespace menu right after the cgroup menu. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:41 +08:00
depends on SYSFS
default n
help
This option adds code that switches the layout of the "block" class
devices, to not show up in /sys/class/block/, but only in
/sys/block/.
This switch is only active when the sysfs.deprecated=1 boot option is
passed or the SYSFS_DEPRECATED_V2 option is set.
This option allows new kernels to run on old distributions and tools,
which might get confused by /sys/class/block/. Since 2007/2008 all
major distributions and tools handle this just fine.
Recent distributions and userspace tools after 2009/2010 depend on
the existence of /sys/class/block/, and will not work with this
option enabled.
Only if you are using a new kernel on an old distribution, you might
need to say Y here.
config SYSFS_DEPRECATED_V2
sysfs: Capitalize description of SYSFS_DEPRECATED{_V2} options Signed-off-by: Ferenc Wagner <wferi@niif.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-11 02:04:22 +08:00
bool "Enable deprecated sysfs features by default"
namespaces Kconfig: move namespace menu location after the cgroup We have the namespaces as a menuconfig like the cgroup. The cgroup and the namespace are two base bricks for the containers. It is more logical to put the namespace menu right after the cgroup menu. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:41 +08:00
default n
depends on SYSFS
depends on SYSFS_DEPRECATED
help
Enable deprecated sysfs by default.
See the CONFIG_SYSFS_DEPRECATED option for more details about this
option.
Only if you are using a new kernel on an old distribution, you might
need to say Y here. Even then, odds are you would not need it
enabled, you can always pass the boot option if absolutely necessary.
config RELAY
bool "Kernel->user space relay support (formerly relayfs)"
relay: Use irq_work instead of plain timer for deferred wakeup Relay avoids calling wake_up_interruptible() for doing the wakeup of readers/consumers, waiting for the generation of new data, from the context of a process which produced the data. This is apparently done to prevent the possibility of a deadlock in case Scheduler itself is is generating data for the relay, after acquiring rq->lock. The following patch used a timer (to be scheduled at next jiffy), for delegating the wakeup to another context. commit 7c9cb38302e78d24e37f7d8a2ea7eed4ae5f2fa7 Author: Tom Zanussi <zanussi@comcast.net> Date: Wed May 9 02:34:01 2007 -0700 relay: use plain timer instead of delayed work relay doesn't need to use schedule_delayed_work() for waking readers when a simple timer will do. Scheduling a plain timer, at next jiffies boundary, to do the wakeup causes a significant wakeup latency for the Userspace client, which makes relay less suitable for the high-frequency low-payload use cases where the data gets generated at a very high rate, like multiple sub buffers getting filled within a milli second. Moreover the timer is re-scheduled on every newly produced sub buffer so the timer keeps getting pushed out if sub buffers are filled in a very quick succession (less than a jiffy gap between filling of 2 sub buffers). As a result relay runs out of sub buffers to store the new data. By using irq_work it is ensured that wakeup of userspace client, blocked in the poll call, is done at earliest (through self IPI or next timer tick) enabling it to always consume the data in time. Also this makes relay consistent with printk & ring buffers (trace), as they too use irq_work for deferred wake up of readers. [arnd@arndb.de: select CONFIG_IRQ_WORK] Link: http://lkml.kernel.org/r/20160912154035.3222156-1-arnd@arndb.de [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1472906487-1559-1-git-send-email-akash.goel@intel.com Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Akash Goel <akash.goel@intel.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-12 04:54:33 +08:00
select IRQ_WORK
namespaces Kconfig: move namespace menu location after the cgroup We have the namespaces as a menuconfig like the cgroup. The cgroup and the namespace are two base bricks for the containers. It is more logical to put the namespace menu right after the cgroup menu. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-28 06:34:41 +08:00
help
This option enables support for relay interface support in
certain file systems (such as debugfs).
It is designed to provide an efficient mechanism for tools and
facilities to relay large amounts of data from kernel space to
user space.
If unsure, say N.
[PATCH] initramfs should not depend on CONFIG_BLOCK initramfs ended up depending on BLOCK: INITRAMFS_SOURCE <-- BLK_DEV_INITRD <-- BLOCK This inhibits use of customized-initramfs-over-ramfs without block layer (ramfs would still be enabled), useful in embedded applications. Move BLK_DEV_INITRD out of 'drivers/block/Kconfig' and into 'init/Kconfig', make it unconditional. Signed-off-by: Dimitri Gorokhovik <dimitri.gorokhovik@free.fr> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-06 17:42:17 +08:00
config BLK_DEV_INITRD
bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
help
The initial RAM filesystem is a ramfs which is loaded by the
boot loader (loadlin or lilo) and that is mounted as root
before the normal boot procedure. It is typically used to
load modules needed to mount the "real" root file system,
docs: fix locations of several documents that got moved The previous patch renamed several files that are cross-referenced along the Kernel documentation. Adjust the links to point to the right places. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-18 20:12:27 +08:00
etc. See <file:Documentation/admin-guide/initrd.rst> for details.
[PATCH] initramfs should not depend on CONFIG_BLOCK initramfs ended up depending on BLOCK: INITRAMFS_SOURCE <-- BLK_DEV_INITRD <-- BLOCK This inhibits use of customized-initramfs-over-ramfs without block layer (ramfs would still be enabled), useful in embedded applications. Move BLK_DEV_INITRD out of 'drivers/block/Kconfig' and into 'init/Kconfig', make it unconditional. Signed-off-by: Dimitri Gorokhovik <dimitri.gorokhovik@free.fr> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-06 17:42:17 +08:00
If RAM disk support (BLK_DEV_RAM) is also included, this
also enables initial RAM disk (initrd) support and adds
15 Kbytes (more on some other architectures) to the kernel size.
If unsure say Y.
[PATCH] disable init/initramfs.c The file init/initramfs.c is always compiled and linked in the kernel vmlinux even when BLK_DEV_RAM and BLK_DEV_INITRD are disabled and the system isn't using any form of an initramfs or initrd. In this situation the code is only used to unpack a (static) default initial rootfilesystem. The current init/initramfs.c code. usr/initramfs_data.o compiles to a size of ~15 kbytes. Disabling BLK_DEV_RAM and BLK_DEV_INTRD shrinks the kernel code size with ~60 Kbytes. This patch avoids compiling in the code and data for initramfs support if CONFIG_BLK_DEV_INITRD is not defined. Instead of the initramfs code and data it uses a small routine in init/noinitramfs.c to setup an initial static default environment for mounting a rootfilesystem later on in the kernel initialisation process. The new code is: 164 bytes of size. The patch is separated in two parts: 1) doesn't compile initramfs code when CONFIG_BLK_DEV_INITRD is not set 2) changing all plaforms vmlinux.lds.S files to not reserve an area of PAGE_SIZE when CONFIG_BLK_DEV_INITRD is not set. [deweerdt@free.fr: warning fix] Signed-off-by: Jean-Paul Saman <jean-paul.saman@nxp.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-10 17:44:43 +08:00
if BLK_DEV_INITRD
kconfig: move initramfs options to General Setup Move initramfs options from Device Drivers | Block Drivers to General Setup This is a more natural place for this option. Furthermore separate out intramfs options to usr/Kconfig Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-08-11 02:44:50 +08:00
source "usr/Kconfig"
[PATCH] disable init/initramfs.c The file init/initramfs.c is always compiled and linked in the kernel vmlinux even when BLK_DEV_RAM and BLK_DEV_INITRD are disabled and the system isn't using any form of an initramfs or initrd. In this situation the code is only used to unpack a (static) default initial rootfilesystem. The current init/initramfs.c code. usr/initramfs_data.o compiles to a size of ~15 kbytes. Disabling BLK_DEV_RAM and BLK_DEV_INTRD shrinks the kernel code size with ~60 Kbytes. This patch avoids compiling in the code and data for initramfs support if CONFIG_BLK_DEV_INITRD is not defined. Instead of the initramfs code and data it uses a small routine in init/noinitramfs.c to setup an initial static default environment for mounting a rootfilesystem later on in the kernel initialisation process. The new code is: 164 bytes of size. The patch is separated in two parts: 1) doesn't compile initramfs code when CONFIG_BLK_DEV_INITRD is not set 2) changing all plaforms vmlinux.lds.S files to not reserve an area of PAGE_SIZE when CONFIG_BLK_DEV_INITRD is not set. [deweerdt@free.fr: warning fix] Signed-off-by: Jean-Paul Saman <jean-paul.saman@nxp.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-10 17:44:43 +08:00
endif
bootconfig: Add Extra Boot Config support Extra Boot Config (XBC) allows admin to pass a tree-structured boot configuration file when boot up the kernel. This extends the kernel command line in an efficient way. Boot config will contain some key-value commands, e.g. key.word = value1 another.key.word = value2 It can fold same keys with braces, also you can write array data. For example, key { word1 { setting1 = data setting2 } word2.array = "val1", "val2" } User can access these key-value pair and tree structure via SKC APIs. Link: http://lkml.kernel.org/r/157867221257.17873.1775090991929862549.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-11 00:03:32 +08:00
config BOOT_CONFIG
bool "Boot config support"
bootconfig: Fix CONFIG_BOOTTIME_TRACING dependency issue Since commit d8a953ddde5e ("bootconfig: Set CONFIG_BOOT_CONFIG=n by default") also changed the CONFIG_BOOTTIME_TRACING to select CONFIG_BOOT_CONFIG to show the boot-time tracing on the menu, it introduced wrong dependencies with BLK_DEV_INITRD as below. WARNING: unmet direct dependencies detected for BOOT_CONFIG Depends on [n]: BLK_DEV_INITRD [=n] Selected by [y]: - BOOTTIME_TRACING [=y] && TRACING_SUPPORT [=y] && FTRACE [=y] && TRACING [=y] This makes the CONFIG_BOOT_CONFIG selects CONFIG_BLK_DEV_INITRD to fix this error and make CONFIG_BOOTTIME_TRACING=n by default, so that both boot-time tracing and boot configuration off but those appear on the menu list. Link: http://lkml.kernel.org/r/158264140162.23842.11237423518607465535.stgit@devnote2 Fixes: d8a953ddde5e ("bootconfig: Set CONFIG_BOOT_CONFIG=n by default") Reported-by: Randy Dunlap <rdunlap@infradead.org> Compiled-tested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-25 22:36:41 +08:00
select BLK_DEV_INITRD
bootconfig: Add Extra Boot Config support Extra Boot Config (XBC) allows admin to pass a tree-structured boot configuration file when boot up the kernel. This extends the kernel command line in an efficient way. Boot config will contain some key-value commands, e.g. key.word = value1 another.key.word = value2 It can fold same keys with braces, also you can write array data. For example, key { word1 { setting1 = data setting2 } word2.array = "val1", "val2" } User can access these key-value pair and tree structure via SKC APIs. Link: http://lkml.kernel.org/r/157867221257.17873.1775090991929862549.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-11 00:03:32 +08:00
help
Extra boot config allows system admin to pass a config file as
complemental extension of kernel cmdline when booting.
bootconfig: Fix Kconfig help message for BOOT_CONFIG Fix Kconfig help message since the bootconfig file is only available to be appended to initramfs. And also add a reference to the documentation. Link: http://lkml.kernel.org/r/157949058031.25888.18399447161895787505.stgit@devnote2 Reported-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-20 11:23:00 +08:00
The boot config file must be attached at the end of initramfs
bootconfig: Add bootconfig magic word for indicating bootconfig explicitly Add bootconfig magic word to the end of bootconfig on initrd image for indicating explicitly the bootconfig is there. Also tools/bootconfig treats wrong size or wrong checksum or parse error as an error, because if there is a bootconfig magic word, there must be a bootconfig. The bootconfig magic word is "#BOOTCONFIG\n", 12 bytes word. Thus the block image of the initrd file with bootconfig is as follows. [Initrd][bootconfig][size][csum][#BOOTCONFIG\n] Link: http://lkml.kernel.org/r/158220112263.26565.3944814205960612841.stgit@devnote2 Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-20 20:18:42 +08:00
with checksum, size and magic word.
bootconfig: Fix Kconfig help message for BOOT_CONFIG Fix Kconfig help message since the bootconfig file is only available to be appended to initramfs. And also add a reference to the documentation. Link: http://lkml.kernel.org/r/157949058031.25888.18399447161895787505.stgit@devnote2 Reported-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-20 11:23:00 +08:00
See <file:Documentation/admin-guide/bootconfig.rst> for details.
bootconfig: Add Extra Boot Config support Extra Boot Config (XBC) allows admin to pass a tree-structured boot configuration file when boot up the kernel. This extends the kernel command line in an efficient way. Boot config will contain some key-value commands, e.g. key.word = value1 another.key.word = value2 It can fold same keys with braces, also you can write array data. For example, key { word1 { setting1 = data setting2 } word2.array = "val1", "val2" } User can access these key-value pair and tree structure via SKC APIs. Link: http://lkml.kernel.org/r/157867221257.17873.1775090991929862549.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-11 00:03:32 +08:00
If unsure, say Y.
Kbuild: change CC_OPTIMIZE_FOR_SIZE definition CC_OPTIMIZE_FOR_SIZE disables the often useful -Wmaybe-unused warning, because that causes a ridiculous amount of false positives when combined with -Os. This means a lot of warnings don't show up in testing by the developers that should see them with an 'allmodconfig' kernel that has CC_OPTIMIZE_FOR_SIZE enabled, but only later in randconfig builds that don't. This changes the Kconfig logic around CC_OPTIMIZE_FOR_SIZE to make it a 'choice' statement defaulting to CC_OPTIMIZE_FOR_PERFORMANCE that gets added for this purpose. The allmodconfig and allyesconfig kernels now default to -O2 with the maybe-unused warning enabled. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-25 23:35:27 +08:00
choice
prompt "Compiler optimization level"
kbuild: Fix optimization level choice default The choice containing the CC_OPTIMIZE_FOR_PERFORMANCE symbol accidentally added a "CONFIG_" prefix when trying to make it the default, selecting an undefined symbol as the default. The mistake is harmless here: Since the default symbol is not visible, the choice falls back on using the visible symbol as the default instead, which is CC_OPTIMIZE_FOR_PERFORMANCE, as intended. A patch that makes Kconfig print a warning in this case has been submitted separately: http://www.spinics.net/lists/linux-kbuild/msg15566.html Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-10-04 07:53:26 +08:00
default CC_OPTIMIZE_FOR_PERFORMANCE
Kbuild: change CC_OPTIMIZE_FOR_SIZE definition CC_OPTIMIZE_FOR_SIZE disables the often useful -Wmaybe-unused warning, because that causes a ridiculous amount of false positives when combined with -Os. This means a lot of warnings don't show up in testing by the developers that should see them with an 'allmodconfig' kernel that has CC_OPTIMIZE_FOR_SIZE enabled, but only later in randconfig builds that don't. This changes the Kconfig logic around CC_OPTIMIZE_FOR_SIZE to make it a 'choice' statement defaulting to CC_OPTIMIZE_FOR_PERFORMANCE that gets added for this purpose. The allmodconfig and allyesconfig kernels now default to -O2 with the maybe-unused warning enabled. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-25 23:35:27 +08:00
config CC_OPTIMIZE_FOR_PERFORMANCE
kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC arch/arc/Makefile overrides -O2 with -O3. This is the only user of ARCH_CFLAGS. There is no user of ARCH_CPPFLAGS or ARCH_AFLAGS. My plan is to remove ARCH_{CPP,A,C}FLAGS after refactoring the ARC Makefile. Currently, ARC has no way to enable -Wmaybe-uninitialized because both -O3 and -Os disable it. Enabling it will be useful for compile-testing. This commit allows allmodconfig (, which defaults to -O2) to enable it. Add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y to all the defconfig files in arch/arc/configs/ in order to keep the current config settings. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Vineet Gupta <vgupta@synopsys.com>
2019-08-21 01:09:40 +08:00
bool "Optimize for performance (-O2)"
Kbuild: change CC_OPTIMIZE_FOR_SIZE definition CC_OPTIMIZE_FOR_SIZE disables the often useful -Wmaybe-unused warning, because that causes a ridiculous amount of false positives when combined with -Os. This means a lot of warnings don't show up in testing by the developers that should see them with an 'allmodconfig' kernel that has CC_OPTIMIZE_FOR_SIZE enabled, but only later in randconfig builds that don't. This changes the Kconfig logic around CC_OPTIMIZE_FOR_SIZE to make it a 'choice' statement defaulting to CC_OPTIMIZE_FOR_PERFORMANCE that gets added for this purpose. The allmodconfig and allyesconfig kernels now default to -O2 with the maybe-unused warning enabled. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-25 23:35:27 +08:00
help
This is the default optimization level for the kernel, building
with the "-O2" compiler flag for best performance and most
helpful compile-time warnings.
kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC arch/arc/Makefile overrides -O2 with -O3. This is the only user of ARCH_CFLAGS. There is no user of ARCH_CPPFLAGS or ARCH_AFLAGS. My plan is to remove ARCH_{CPP,A,C}FLAGS after refactoring the ARC Makefile. Currently, ARC has no way to enable -Wmaybe-uninitialized because both -O3 and -Os disable it. Enabling it will be useful for compile-testing. This commit allows allmodconfig (, which defaults to -O2) to enable it. Add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y to all the defconfig files in arch/arc/configs/ in order to keep the current config settings. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Vineet Gupta <vgupta@synopsys.com>
2019-08-21 01:09:40 +08:00
config CC_OPTIMIZE_FOR_PERFORMANCE_O3
bool "Optimize more for performance (-O3)"
depends on ARC
Move size optimization option outside of EMBEDDED menu, mark it EXPERIMENTAL Also, disable on sparc64 - a number of people report breakage. Probably a compiler bug, but it's quite possible that it tickles some latent kernel problem too. It still defaults to 'y' everywhere else (when enabled through EXPERIMENTAL), and Dave Jones points out that Fedora (and RHEL4) has been building with size optimizations for a long time on x86, x86-64, ia64, s390, s390x, ppc32 and ppc64. So it is really only moderately experimental, but the sparc64 breakage certainly shows that it can trigger "issues". Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-15 10:52:21 +08:00
help
kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC arch/arc/Makefile overrides -O2 with -O3. This is the only user of ARCH_CFLAGS. There is no user of ARCH_CPPFLAGS or ARCH_AFLAGS. My plan is to remove ARCH_{CPP,A,C}FLAGS after refactoring the ARC Makefile. Currently, ARC has no way to enable -Wmaybe-uninitialized because both -O3 and -Os disable it. Enabling it will be useful for compile-testing. This commit allows allmodconfig (, which defaults to -O2) to enable it. Add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y to all the defconfig files in arch/arc/configs/ in order to keep the current config settings. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Vineet Gupta <vgupta@synopsys.com>
2019-08-21 01:09:40 +08:00
Choosing this option will pass "-O3" to your compiler to optimize
the kernel yet more for performance.
Move size optimization option outside of EMBEDDED menu, mark it EXPERIMENTAL Also, disable on sparc64 - a number of people report breakage. Probably a compiler bug, but it's quite possible that it tickles some latent kernel problem too. It still defaults to 'y' everywhere else (when enabled through EXPERIMENTAL), and Dave Jones points out that Fedora (and RHEL4) has been building with size optimizations for a long time on x86, x86-64, ia64, s390, s390x, ppc32 and ppc64. So it is really only moderately experimental, but the sparc64 breakage certainly shows that it can trigger "issues". Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-15 10:52:21 +08:00
config CC_OPTIMIZE_FOR_SIZE
kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC arch/arc/Makefile overrides -O2 with -O3. This is the only user of ARCH_CFLAGS. There is no user of ARCH_CPPFLAGS or ARCH_AFLAGS. My plan is to remove ARCH_{CPP,A,C}FLAGS after refactoring the ARC Makefile. Currently, ARC has no way to enable -Wmaybe-uninitialized because both -O3 and -Os disable it. Enabling it will be useful for compile-testing. This commit allows allmodconfig (, which defaults to -O2) to enable it. Add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y to all the defconfig files in arch/arc/configs/ in order to keep the current config settings. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Vineet Gupta <vgupta@synopsys.com>
2019-08-21 01:09:40 +08:00
bool "Optimize for size (-Os)"
Move size optimization option outside of EMBEDDED menu, mark it EXPERIMENTAL Also, disable on sparc64 - a number of people report breakage. Probably a compiler bug, but it's quite possible that it tickles some latent kernel problem too. It still defaults to 'y' everywhere else (when enabled through EXPERIMENTAL), and Dave Jones points out that Fedora (and RHEL4) has been building with size optimizations for a long time on x86, x86-64, ia64, s390, s390x, ppc32 and ppc64. So it is really only moderately experimental, but the sparc64 breakage certainly shows that it can trigger "issues". Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-15 10:52:21 +08:00
help
init/Kconfig: rework help of CONFIG_CC_OPTIMIZE_FOR_SIZE CONFIG_CC_OPTIMIZE_FOR_SIZE was originally an independent boolean option, but commit 877417e6ffb9 ("Kbuild: change CC_OPTIMIZE_FOR_SIZE definition") turned it into a choice between _PERFORMANCE and _SIZE. The phrase "If unsure, say N." sounds like an independent option. Reword the help text to make it appropriate for the choice menu. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-21 01:09:39 +08:00
Choosing this option will pass "-Os" to your compiler resulting
in a smaller kernel.
Move size optimization option outside of EMBEDDED menu, mark it EXPERIMENTAL Also, disable on sparc64 - a number of people report breakage. Probably a compiler bug, but it's quite possible that it tickles some latent kernel problem too. It still defaults to 'y' everywhere else (when enabled through EXPERIMENTAL), and Dave Jones points out that Fedora (and RHEL4) has been building with size optimizations for a long time on x86, x86-64, ia64, s390, s390x, ppc32 and ppc64. So it is really only moderately experimental, but the sparc64 breakage certainly shows that it can trigger "issues". Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-15 10:52:21 +08:00
Kbuild: change CC_OPTIMIZE_FOR_SIZE definition CC_OPTIMIZE_FOR_SIZE disables the often useful -Wmaybe-unused warning, because that causes a ridiculous amount of false positives when combined with -Os. This means a lot of warnings don't show up in testing by the developers that should see them with an 'allmodconfig' kernel that has CC_OPTIMIZE_FOR_SIZE enabled, but only later in randconfig builds that don't. This changes the Kconfig logic around CC_OPTIMIZE_FOR_SIZE to make it a 'choice' statement defaulting to CC_OPTIMIZE_FOR_PERFORMANCE that gets added for this purpose. The allmodconfig and allyesconfig kernels now default to -O2 with the maybe-unused warning enabled. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-25 23:35:27 +08:00
endchoice
kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled Architectures that are capable can select HAVE_LD_DEAD_CODE_DATA_ELIMINATION to enable selection of that option (as an EXPERT kernel option). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-09 21:00:00 +08:00
config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
bool
help
This requires that the arch annotates or otherwise protects
its external entry points from being discarded. Linker scripts
must also merge .text.*, .data.*, and .bss.* correctly into
output sections. Care must be taken not to pull in unrelated
sections (e.g., '.text.init'). Typically '.' in section names
is used to distinguish them from label names / C identifiers.
config LD_DEAD_CODE_DATA_ELIMINATION
bool "Dead code and data elimination (EXPERIMENTAL)"
depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
depends on EXPERT
kbuild: test dead code/data elimination support in Kconfig This config option should be enabled only when both the compiler and the linker support necessary flags. Add proper dependencies to Kconfig. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-22 21:51:09 +08:00
depends on $(cc-option,-ffunction-sections -fdata-sections)
depends on $(ld-option,--gc-sections)
kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled Architectures that are capable can select HAVE_LD_DEAD_CODE_DATA_ELIMINATION to enable selection of that option (as an EXPERT kernel option). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-09 21:00:00 +08:00
help
kbuild: reword help of LD_DEAD_CODE_DATA_ELIMINATION Since commit 5d20ee3192a5 ("kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled"), HAVE_LD_DEAD_CODE_DATA_ELIMINATION is supposed to be selected by architectures that are capable of this functionality. LD_DEAD_CODE_DATA_ELIMINATION is now users' selection. Update the help message. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-24 00:41:51 +08:00
Enable this if you want to do dead code and data elimination with
the linker by compiling with -ffunction-sections -fdata-sections,
and linking with --gc-sections.
kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled Architectures that are capable can select HAVE_LD_DEAD_CODE_DATA_ELIMINATION to enable selection of that option (as an EXPERT kernel option). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-09 21:00:00 +08:00
This can reduce on disk and in-memory size of the kernel
code and static data, particularly for small configs and
on small systems. This has the possibility of introducing
silently broken kernel if the required annotations are not
present. This option is not well tested yet, so use at your
own risk.
[PATCH] fix EMBEDDED + SYSCTL menu SYSCTL should still depend on EMBEDDED. This unbreaks the EMBEDDED menu (from the recent SYSCTL_SYCALL menu option patch). Fix typos in new SYSCTL_SYSCALL menu. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 14:28:13 +08:00
config SYSCTL
bool
init/Kconfig: re-order CONFIG_EXPERT options to fix menuconfig display The kconfig language requires that dependent options all follow the menuconfig symbol in order to be collapsed below it. Recently some hidden options were added below the EXPERT menuconfig, but did not depend on EXPERT (because hidden options can't). This broke the display. So re-order all these options, and while we're here stick the PCI quirks under the EXPERT menu (since it isn't sitting with any related options). Before this commit, we get: [*] Configure standard kernel features (expert users) ---> [ ] Sysctl syscall support [*] Load all symbols for debugging/ksymoops ... [ ] Embedded system Now we get the older (and correct) behavior: [*] Configure standard kernel features (expert users) ---> [ ] Embedded system And if you go into the expert menu you get the expert options: [ ] Sysctl syscall support [*] Load all symbols for debugging/ksymoops ... Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01 06:28:45 +08:00
config HAVE_UID16
bool
config SYSCTL_EXCEPTION_TRACE
bool
help
Enable support for /proc/sys/debug/exception-trace.
config SYSCTL_ARCH_UNALIGN_NO_WARN
bool
help
Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
Allows arch to define/use @no_unaligned_warning to possibly warn
about unaligned access emulation going on under the hood.
config SYSCTL_ARCH_UNALIGN_ALLOW
bool
help
Enable support for /proc/sys/kernel/unaligned-trap
Allows arches to define/use @unaligned_enabled to runtime toggle
the unaligned access emulation.
see arch/parisc/kernel/unaligned.c for reference
config HAVE_PCSPKR_PLATFORM
bool
bpf: split eBPF out of NET introduce two configs: - hidden CONFIG_BPF to select eBPF interpreter that classic socket filters depend on - visible CONFIG_BPF_SYSCALL (default off) that tracing and sockets can use that solves several problems: - tracing and others that wish to use eBPF don't need to depend on NET. They can use BPF_SYSCALL to allow loading from userspace or select BPF to use it directly from kernel in NET-less configs. - in 3.18 programs cannot be attached to events yet, so don't force it on - when the rest of eBPF infra is there in 3.19+, it's still useful to switch it off to minimize kernel size bloat-o-meter on x64 shows: add/remove: 0/60 grow/shrink: 0/2 up/down: 0/-15601 (-15601) tested with many different config combinations. Hopefully didn't miss anything. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-24 09:41:08 +08:00
# interpreter that classic socket filters depend on
config BPF
bool
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
menuconfig EXPERT
bool "Configure standard kernel features (expert users)"
debug: Make CONFIG_EXPERT select CONFIG_DEBUG_KERNEL to unhide debug options Several debugging options currently default to y, such as CONFIG_DEBUG_BUGVERBOSE and CONFIG_DEBUG_RODATA. Embedded users might want to turn those options off to save space; however, turning them off requires turning on CONFIG_DEBUG_KERNEL to unhide them. Since CONFIG_DEBUG_KERNEL exists specifically to unhide debugging options, and CONFIG_EXPERT exists specifically to unhide options potentially needed by experts and/or embedded users, make CONFIG_EXPERT automatically imply CONFIG_DEBUG_KERNEL. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20110606012358.GA1909@leaf Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-06 09:23:58 +08:00
# Unhide debug options, to make the on-by-default options visible
select DEBUG_KERNEL
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
help
This option allows certain base kernel options and settings
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
to be disabled or tweaked. This is for specialized
environments which can tolerate a "non-standard" kernel.
Only use this if you really know what you are doing.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
[PATCH] Kconfig: move CONFIG_EMBEDDED options to submenu Fix two problems with the CONFIG_EMBEDDED submenu: (1) The menu was split in two by the rt_mutex patch, which moved half the items into the "General setup" menu. (2) CONFIG_SYSCTL and CONFIG_UID16 were added to the main menu instead of the submenu. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-17 03:15:53 +08:00
config UID16
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable 16-bit UID system calls" if EXPERT
kernel: conditionally support non-root users, groups and capabilities There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-16 07:16:41 +08:00
depends on HAVE_UID16 && MULTIUSER
[PATCH] Kconfig: move CONFIG_EMBEDDED options to submenu Fix two problems with the CONFIG_EMBEDDED submenu: (1) The menu was split in two by the rt_mutex patch, which moved half the items into the "General setup" menu. (2) CONFIG_SYSCTL and CONFIG_UID16 were added to the main menu instead of the submenu. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-17 03:15:53 +08:00
default y
help
This enables the legacy 16-bit UID syscall wrappers.
kernel: conditionally support non-root users, groups and capabilities There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-16 07:16:41 +08:00
config MULTIUSER
bool "Multiple users, groups and capabilities support" if EXPERT
default y
help
This option enables support for non-root users, groups and
capabilities.
If you say N here, all processes will run with UID 0, GID 0, and all
possible capabilities. Saying N here also compiles out support for
system calls related to UIDs, GIDs, and capabilities, such as setuid,
setgid, and capset.
If unsure, say Y here.
sys_sgetmask/sys_ssetmask: add CONFIG_SGETMASK_SYSCALL sys_sgetmask and sys_ssetmask are obsolete system calls no longer supported in libc. This patch replaces architecture related __ARCH_WANT_SYS_SGETMAX by expert mode configuration.That option is enabled by default for those architectures. Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Steven Miao <realmz6@gmail.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg Ungerer <gerg@uclinux.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-05 07:11:12 +08:00
config SGETMASK_SYSCALL
bool "sgetmask/ssetmask syscalls support" if EXPERT
treewide: simplify Kconfig dependencies for removed archs A lot of Kconfig symbols have architecture specific dependencies. In those cases that depend on architectures we have already removed, they can be omitted. Acked-by: Kalle Valo <kvalo@codeaurora.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-08 06:30:54 +08:00
def_bool PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH
treewide: replace '---help---' in Kconfig files with 'help' Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 00:50:22 +08:00
help
sys_sgetmask/sys_ssetmask: add CONFIG_SGETMASK_SYSCALL sys_sgetmask and sys_ssetmask are obsolete system calls no longer supported in libc. This patch replaces architecture related __ARCH_WANT_SYS_SGETMAX by expert mode configuration.That option is enabled by default for those architectures. Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Steven Miao <realmz6@gmail.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg Ungerer <gerg@uclinux.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-05 07:11:12 +08:00
sys_sgetmask and sys_ssetmask are obsolete system calls
no longer supported in libc but still enabled by default in some
architectures.
If unsure, leave the default option here.
sys_sysfs: Add CONFIG_SYSFS_SYSCALL sys_sysfs is an obsolete system call no longer supported by libc. - This patch adds a default CONFIG_SYSFS_SYSCALL=y - Option can be turned off in expert mode. - cond_syscall added to kernel/sys_ni.c [akpm@linux-foundation.org: tweak Kconfig help text] Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 05:48:25 +08:00
config SYSFS_SYSCALL
bool "Sysfs syscall support" if EXPERT
default y
treewide: replace '---help---' in Kconfig files with 'help' Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 00:50:22 +08:00
help
sys_sysfs: Add CONFIG_SYSFS_SYSCALL sys_sysfs is an obsolete system call no longer supported by libc. - This patch adds a default CONFIG_SYSFS_SYSCALL=y - Option can be turned off in expert mode. - cond_syscall added to kernel/sys_ni.c [akpm@linux-foundation.org: tweak Kconfig help text] Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-04 05:48:25 +08:00
sys_sysfs is an obsolete system call no longer supported in libc.
Note that disabling this option is more secure but might break
compatibility with some systems.
If unsure say Y here.
EXPERT Kconfig menu: fix broken EXPERT menu Clean up the EXPERT menu (yet again). Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since they already depend on EXPERT. Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu list since they do not depend on EXPERT and were breaking the continuity of that menu list. Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu. This separates the kernel services from the build options. This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu (https://lkml.org/lkml/2017/11/2/907). Link: http://lkml.kernel.org/r/72e4465a-a5ff-cb3c-1a90-11aa4861b161@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> [BPF] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18 07:31:47 +08:00
config FHANDLE
bool "open by fhandle syscalls" if EXPERT
select EXPORTFS
default y
help
If you say Y here, a user level program will be able to map
file names to handle and then later use the handle for
different file system operations. This is useful in implementing
userspace file servers, which now track files using handles instead
of names. The handle would remain the same even if file names
get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
syscalls.
posix-timers: Make them configurable Some embedded systems have no use for them. This removes about 25KB from the kernel binary size when configured out. Corresponding syscalls are routed to a stub logging the attempt to use those syscalls which should be enough of a clue if they were disabled without proper consideration. They are: timer_create, timer_gettime: timer_getoverrun, timer_settime, timer_delete, clock_adjtime, setitimer, getitimer, alarm. The clock_settime, clock_gettime, clock_getres and clock_nanosleep syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast majority of use cases with very little code. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Michal Marek <mmarek@suse.com> Cc: Edward Cree <ecree@solarflare.com> Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-11 13:10:10 +08:00
config POSIX_TIMERS
bool "Posix Clocks & timers" if EXPERT
default y
help
This includes native support for POSIX timers to the kernel.
Some embedded systems have no use for them and therefore they
can be configured out to reduce the size of the kernel image.
When this option is disabled, the following syscalls won't be
available: timer_create, timer_gettime: timer_getoverrun,
timer_settime, timer_delete, clock_adjtime, getitimer,
setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
clock_getres and clock_nanosleep syscalls will be limited to
CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
If unsure say y.
[PATCH] clean up kernel messages Arrange for all kernel printks to be no-ops. Only available if CONFIG_EMBEDDED. This patch saves about 375k on my laptop config and nearly 100k on minimal configs. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 23:59:02 +08:00
config PRINTK
default y
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable support for printk" if EXPERT
printk: Wake up klogd using irq_work klogd is woken up asynchronously from the tick in order to do it safely. However if printk is called when the tick is stopped, the reader won't be woken up until the next interrupt, which might not fire for a while. As a result, the user may miss some message. To fix this, lets implement the printk tick using a lazy irq work. This subsystem takes care of the timer tick state and can fix up accordingly. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-10-13 00:00:23 +08:00
select IRQ_WORK
[PATCH] clean up kernel messages Arrange for all kernel printks to be no-ops. Only available if CONFIG_EMBEDDED. This patch saves about 375k on my laptop config and nearly 100k on minimal configs. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 23:59:02 +08:00
help
This option enables normal printk support. Removing it
eliminates most of the message strings from the kernel image
and makes the kernel more or less silent. As this makes it
very difficult to diagnose system problems, saying N here is
strongly discouraged.
printk/nmi: generic solution for safe printk in NMI printk() takes some locks and could not be used a safe way in NMI context. The chance of a deadlock is real especially when printing stacks from all CPUs. This particular problem has been addressed on x86 by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). The patchset brings two big advantages. First, it makes the NMI backtraces safe on all architectures for free. Second, it makes all NMI messages almost safe on all architectures (the temporary buffer is limited. We still should keep the number of messages in NMI context at minimum). Note that there already are several messages printed in NMI context: WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE handlers. These are not easy to avoid. This patch reuses most of the code and makes it generic. It is useful for all messages and architectures that support NMI. The alternative printk_func is set when entering and is reseted when leaving NMI context. It queues IRQ work to copy the messages into the main ring buffer in a safe context. __printk_nmi_flush() copies all available messages and reset the buffer. Then we could use a simple cmpxchg operations to get synchronized with writers. There is also used a spinlock to get synchronized with other flushers. We do not longer use seq_buf because it depends on external lock. It would be hard to make all supported operations safe for a lockless use. It would be confusing and error prone to make only some operations safe. The code is put into separate printk/nmi.c as suggested by Steven Rostedt. It needs a per-CPU buffer and is compiled only on architectures that call nmi_enter(). This is achieved by the new HAVE_NMI Kconfig flag. The are MN10300 and Xtensa architectures. We need to clean up NMI handling there first. Let's do it separately. The patch is heavily based on the draft from Peter Zijlstra, see https://lkml.org/lkml/2015/6/10/327 [arnd@arndb.de: printk-nmi: use %zu format string for size_t] [akpm@linux-foundation.org: min_t->min - all types are size_t here] Signed-off-by: Petr Mladek <pmladek@suse.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Cc: Jan Kara <jack@suse.cz> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> [arm part] Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jiri Kosina <jkosina@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: David Miller <davem@davemloft.net> Cc: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21 08:00:33 +08:00
config PRINTK_NMI
def_bool y
depends on PRINTK
depends on HAVE_NMI
[PATCH] remove all kernel BUGs This patch eliminates all kernel BUGs, trims about 35k off the typical kernel, and makes the system slightly faster. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 23:59:01 +08:00
config BUG
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "BUG() support" if EXPERT
[PATCH] remove all kernel BUGs This patch eliminates all kernel BUGs, trims about 35k off the typical kernel, and makes the system slightly faster. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 23:59:01 +08:00
default y
help
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
Disabling this option eliminates support for BUG and WARN, reducing
the size of your kernel image and potentially quietly ignoring
numerous fatal conditions. You should only consider disabling this
option for embedded systems with no facilities for reporting errors.
Just say Y.
[PATCH] remove all kernel BUGs This patch eliminates all kernel BUGs, trims about 35k off the typical kernel, and makes the system slightly faster. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 23:59:01 +08:00
[PATCH] tiny: Configure ELF core dump support configurable support for ELF core dumps text data bss dec hex filename 3330172 529036 190556 4049764 3dcb64 vmlinux-baseline 3325552 528912 190556 4045020 3db8dc vmlinux-no-elf add/remove: 0/8 grow/shrink: 0/0 up/down: 0/-4424 (-4424) function old new delta fill_note 32 - -32 maydump 58 - -58 dump_seek 67 - -67 writenote 180 - -180 elf_dump_thread_status 274 - -274 fill_psinfo 308 - -308 fill_prstatus 466 - -466 elf_core_dump 3039 - -3039 Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 17:05:25 +08:00
config ELF_CORE
coredump: make core dump functionality optional Adds an expert Kconfig option, CONFIG_COREDUMP, which allows disabling of core dump. This saves approximately 2.6k in the compiled kernel, and complements CONFIG_ELF_CORE, which now depends on it. CONFIG_COREDUMP also disables coredump-related sysctls, except for suid_dumpable and related functions, which are necessary for ptrace. [akpm@linux-foundation.org: fix binfmt_aout.c build] Signed-off-by: Alex Kelly <alex.page.kelly@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-05 08:15:23 +08:00
depends on COREDUMP
[PATCH] tiny: Configure ELF core dump support configurable support for ELF core dumps text data bss dec hex filename 3330172 529036 190556 4049764 3dcb64 vmlinux-baseline 3325552 528912 190556 4045020 3db8dc vmlinux-no-elf add/remove: 0/8 grow/shrink: 0/0 up/down: 0/-4424 (-4424) function old new delta fill_note 32 - -32 maydump 58 - -58 dump_seek 67 - -67 writenote 180 - -180 elf_dump_thread_status 274 - -274 fill_psinfo 308 - -308 fill_prstatus 466 - -466 elf_core_dump 3039 - -3039 Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 17:05:25 +08:00
default y
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable ELF core dumps" if EXPERT
[PATCH] tiny: Configure ELF core dump support configurable support for ELF core dumps text data bss dec hex filename 3330172 529036 190556 4049764 3dcb64 vmlinux-baseline 3325552 528912 190556 4045020 3db8dc vmlinux-no-elf add/remove: 0/8 grow/shrink: 0/0 up/down: 0/-4424 (-4424) function old new delta fill_note 32 - -32 maydump 58 - -58 dump_seek 67 - -67 writenote 180 - -180 elf_dump_thread_status 274 - -274 fill_psinfo 308 - -308 fill_prstatus 466 - -466 elf_core_dump 3039 - -3039 Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 17:05:25 +08:00
help
Enable support for generating core dumps. Disabling saves about 4k.
pcspkr: Cleanup Kconfig dependencies Lenghty lists of the kind "depends on ARCH1 || ARCH2 ... || ARCH123" are usually either wrong or too coarse grained. Or plain an ugly sin. [ tglx: Fixed up amigaone ] Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linux-alpha@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Gerhard Pircher <gerhard_pircher@gmx.net> Link: http://lkml.kernel.org/r/20110601180610.984881988@duck.linux-mips.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-06-02 02:05:09 +08:00
pcspkr: fix dependancies fix pcspkr dependancies: make the pcspkr platform drivers to depend on a platform device, and not the other way around. Signed-off-by: Stas Sergeev <stsp@aknet.ru> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Dmitry Torokhov <dtor@mail.ru> CC: Vojtech Pavlik <vojtech@suse.cz> CC: Michael Opdenacker <michael-lists@free-electrons.com> [fixed for 2.6.26-rc1 by tiwai] Signed-off-by: Takashi Iwai <tiwai@suse.de>
2008-05-07 18:39:56 +08:00
config PCSPKR_PLATFORM
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable PC-Speaker support" if EXPERT
pcspkr: Cleanup Kconfig dependencies Lenghty lists of the kind "depends on ARCH1 || ARCH2 ... || ARCH123" are usually either wrong or too coarse grained. Or plain an ugly sin. [ tglx: Fixed up amigaone ] Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linux-alpha@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Gerhard Pircher <gerhard_pircher@gmx.net> Link: http://lkml.kernel.org/r/20110601180610.984881988@duck.linux-mips.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-06-02 02:05:09 +08:00
depends on HAVE_PCSPKR_PLATFORM
i8253: Consolidate all kernel definitions of i8253_lock Move them to drivers/clocksource/i8253.c and remove the implementations in arch/ [ tglx: Avoid the extra file in lib - folded arch patches in. The export will become conditional in a later step ] Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Link: http://lkml.kernel.org/r/20110601180610.221426078@duck.linux-mips.net Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-06-02 02:04:59 +08:00
select I8253_LOCK
pcspkr: fix dependancies fix pcspkr dependancies: make the pcspkr platform drivers to depend on a platform device, and not the other way around. Signed-off-by: Stas Sergeev <stsp@aknet.ru> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Dmitry Torokhov <dtor@mail.ru> CC: Vojtech Pavlik <vojtech@suse.cz> CC: Michael Opdenacker <michael-lists@free-electrons.com> [fixed for 2.6.26-rc1 by tiwai] Signed-off-by: Takashi Iwai <tiwai@suse.de>
2008-05-07 18:39:56 +08:00
default y
help
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
This option allows to disable the internal PC-Speaker
support, saving some memory.
pcspkr: fix dependancies fix pcspkr dependancies: make the pcspkr platform drivers to depend on a platform device, and not the other way around. Signed-off-by: Stas Sergeev <stsp@aknet.ru> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Dmitry Torokhov <dtor@mail.ru> CC: Vojtech Pavlik <vojtech@suse.cz> CC: Michael Opdenacker <michael-lists@free-electrons.com> [fixed for 2.6.26-rc1 by tiwai] Signed-off-by: Takashi Iwai <tiwai@suse.de>
2008-05-07 18:39:56 +08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config BASE_FULL
default y
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable full-sized data structures for core" if EXPERT
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
help
Disabling this option reduces the size of miscellaneous core
kernel data structures. This saves memory on small machines,
but may reduce performance.
config FUTEX
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable futex support" if EXPERT
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
default y
futex: Allow for compiling out PI support This makes it possible to preserve basic futex support and compile out the PI support when RT mutexes are not available. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <dvhart@infradead.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.20.1708010024190.5981@knanqh.ubzr
2017-08-01 12:31:32 +08:00
imply RT_MUTEXES
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
help
Disabling this option will cause the kernel to be built without
support for "fast userspace mutexes". The resulting kernel may not
run glibc-based applications correctly.
futex: Allow for compiling out PI support This makes it possible to preserve basic futex support and compile out the PI support when RT mutexes are not available. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <dvhart@infradead.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.20.1708010024190.5981@knanqh.ubzr
2017-08-01 12:31:32 +08:00
config FUTEX_PI
bool
depends on FUTEX && RT_MUTEXES
default y
futex: Allow architectures to skip futex_atomic_cmpxchg_inatomic() test If an architecture has futex_atomic_cmpxchg_inatomic() implemented and there is no runtime check necessary, allow to skip the test within futex_init(). This allows to get rid of some code which would always give the same result, and also allows the compiler to optimize a couple of if statements away. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Finn Thain <fthain@telegraphics.com.au> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/20140302120947.GA3641@osiris Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-03-02 20:09:47 +08:00
config HAVE_FUTEX_CMPXCHG
bool
init/Kconfig: Fix HAVE_FUTEX_CMPXCHG to not break up the EXPERT menu commit 03b8c7b623c80af264c4c8d6111e5c6289933666 ("futex: Allow architectures to skip futex_atomic_cmpxchg_inatomic() test") added the HAVE_FUTEX_CMPXCHG symbol right below FUTEX. This placed it right in the middle of the options for the EXPERT menu. However, HAVE_FUTEX_CMPXCHG does not depend on EXPERT or FUTEX, so Kconfig stops placing items in the EXPERT menu, and displays the remaining several EXPERT items (starting with EPOLL) directly in the General Setup menu. Since both users of HAVE_FUTEX_CMPXCHG only select it "if FUTEX", make HAVE_FUTEX_CMPXCHG itself depend on FUTEX. With this change, the subsequent items display as part of the EXPERT menu again; the EMBEDDED menu now appears as the next top-level item in the General Setup menu, which makes General Setup much shorter and more usable. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: stable <stable@vger.kernel.org>
2014-10-04 07:19:24 +08:00
depends on FUTEX
futex: Allow architectures to skip futex_atomic_cmpxchg_inatomic() test If an architecture has futex_atomic_cmpxchg_inatomic() implemented and there is no runtime check necessary, allow to skip the test within futex_init(). This allows to get rid of some code which would always give the same result, and also allows the compiler to optimize a couple of if statements away. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Finn Thain <fthain@telegraphics.com.au> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/20140302120947.GA3641@osiris Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-03-02 20:09:47 +08:00
help
Architectures should select this if futex_atomic_cmpxchg_inatomic()
is implemented and always working. This removes a couple of runtime
checks.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config EPOLL
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable eventpoll support" if EXPERT
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
default y
help
Disabling this option will cause the kernel to be built without
support for epoll family of system calls.
signal/timer/event: signalfd core This patch series implements the new signalfd() system call. I took part of the original Linus code (and you know how badly it can be broken :), and I added even more breakage ;) Signals are fetched from the same signal queue used by the process, so signalfd will compete with standard kernel delivery in dequeue_signal(). If you want to reliably fetch signals on the signalfd file, you need to block them with sigprocmask(SIG_BLOCK). This seems to be working fine on my Dual Opteron machine. I made a quick test program for it: http://www.xmailserver.org/signafd-test.c The signalfd() system call implements signal delivery into a file descriptor receiver. The signalfd file descriptor if created with the following API: int signalfd(int ufd, const sigset_t *mask, size_t masksize); The "ufd" parameter allows to change an existing signalfd sigmask, w/out going to close/create cycle (Linus idea). Use "ufd" == -1 if you want a brand new signalfd file. The "mask" allows to specify the signal mask of signals that we are interested in. The "masksize" parameter is the size of "mask". The signalfd fd supports the poll(2) and read(2) system calls. The poll(2) will return POLLIN when signals are available to be dequeued. As a direct consequence of supporting the Linux poll subsystem, the signalfd fd can use used together with epoll(2) too. The read(2) system call will return a "struct signalfd_siginfo" structure in the userspace supplied buffer. The return value is the number of bytes copied in the supplied buffer, or -1 in case of error. The read(2) call can also return 0, in case the sighand structure to which the signalfd was attached, has been orphaned. The O_NONBLOCK flag is also supported, and read(2) will return -EAGAIN in case no signal is available. If the size of the buffer passed to read(2) is lower than sizeof(struct signalfd_siginfo), -EINVAL is returned. A read from the signalfd can also return -ERESTARTSYS in case a signal hits the process. The format of the struct signalfd_siginfo is, and the valid fields depends of the (->code & __SI_MASK) value, in the same way a struct siginfo would: struct signalfd_siginfo { __u32 signo; /* si_signo */ __s32 err; /* si_errno */ __s32 code; /* si_code */ __u32 pid; /* si_pid */ __u32 uid; /* si_uid */ __s32 fd; /* si_fd */ __u32 tid; /* si_fd */ __u32 band; /* si_band */ __u32 overrun; /* si_overrun */ __u32 trapno; /* si_trapno */ __s32 status; /* si_status */ __s32 svint; /* si_int */ __u64 svptr; /* si_ptr */ __u64 utime; /* si_utime */ __u64 stime; /* si_stime */ __u64 addr; /* si_addr */ }; [akpm@linux-foundation.org: fix signalfd_copyinfo() on i386] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 13:23:13 +08:00
config SIGNALFD
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable signalfd() system call" if EXPERT
signal/timer/event: signalfd core This patch series implements the new signalfd() system call. I took part of the original Linus code (and you know how badly it can be broken :), and I added even more breakage ;) Signals are fetched from the same signal queue used by the process, so signalfd will compete with standard kernel delivery in dequeue_signal(). If you want to reliably fetch signals on the signalfd file, you need to block them with sigprocmask(SIG_BLOCK). This seems to be working fine on my Dual Opteron machine. I made a quick test program for it: http://www.xmailserver.org/signafd-test.c The signalfd() system call implements signal delivery into a file descriptor receiver. The signalfd file descriptor if created with the following API: int signalfd(int ufd, const sigset_t *mask, size_t masksize); The "ufd" parameter allows to change an existing signalfd sigmask, w/out going to close/create cycle (Linus idea). Use "ufd" == -1 if you want a brand new signalfd file. The "mask" allows to specify the signal mask of signals that we are interested in. The "masksize" parameter is the size of "mask". The signalfd fd supports the poll(2) and read(2) system calls. The poll(2) will return POLLIN when signals are available to be dequeued. As a direct consequence of supporting the Linux poll subsystem, the signalfd fd can use used together with epoll(2) too. The read(2) system call will return a "struct signalfd_siginfo" structure in the userspace supplied buffer. The return value is the number of bytes copied in the supplied buffer, or -1 in case of error. The read(2) call can also return 0, in case the sighand structure to which the signalfd was attached, has been orphaned. The O_NONBLOCK flag is also supported, and read(2) will return -EAGAIN in case no signal is available. If the size of the buffer passed to read(2) is lower than sizeof(struct signalfd_siginfo), -EINVAL is returned. A read from the signalfd can also return -ERESTARTSYS in case a signal hits the process. The format of the struct signalfd_siginfo is, and the valid fields depends of the (->code & __SI_MASK) value, in the same way a struct siginfo would: struct signalfd_siginfo { __u32 signo; /* si_signo */ __s32 err; /* si_errno */ __s32 code; /* si_code */ __u32 pid; /* si_pid */ __u32 uid; /* si_uid */ __s32 fd; /* si_fd */ __u32 tid; /* si_fd */ __u32 band; /* si_band */ __u32 overrun; /* si_overrun */ __u32 trapno; /* si_trapno */ __s32 status; /* si_status */ __s32 svint; /* si_int */ __u64 svptr; /* si_ptr */ __u64 utime; /* si_utime */ __u64 stime; /* si_stime */ __u64 addr; /* si_addr */ }; [akpm@linux-foundation.org: fix signalfd_copyinfo() on i386] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 13:23:13 +08:00
default y
help
Enable the signalfd() system call that allows to receive signals
on a file descriptor.
If unsure, say Y.
signal/timer/event: timerfd core This patch introduces a new system call for timers events delivered though file descriptors. This allows timer event to be used with standard POSIX poll(2), select(2) and read(2). As a consequence of supporting the Linux f_op->poll subsystem, they can be used with epoll(2) too. The system call is defined as: int timerfd(int ufd, int clockid, int flags, const struct itimerspec *utmr); The "ufd" parameter allows for re-use (re-programming) of an existing timerfd w/out going through the close/open cycle (same as signalfd). If "ufd" is -1, s new file descriptor will be created, otherwise the existing "ufd" will be re-programmed. The "clockid" parameter is either CLOCK_MONOTONIC or CLOCK_REALTIME. The time specified in the "utmr->it_value" parameter is the expiry time for the timer. If the TFD_TIMER_ABSTIME flag is set in "flags", this is an absolute time, otherwise it's a relative time. If the time specified in the "utmr->it_interval" is not zero (.tv_sec == 0, tv_nsec == 0), this is the period at which the following ticks should be generated. The "utmr->it_interval" should be set to zero if only one tick is requested. Setting the "utmr->it_value" to zero will disable the timer, or will create a timerfd without the timer enabled. The function returns the new (or same, in case "ufd" is a valid timerfd descriptor) file, or -1 in case of error. As stated before, the timerfd file descriptor supports poll(2), select(2) and epoll(2). When a timer event happened on the timerfd, a POLLIN mask will be returned. The read(2) call can be used, and it will return a u32 variable holding the number of "ticks" that happened on the interface since the last call to read(2). The read(2) call supportes the O_NONBLOCK flag too, and EAGAIN will be returned if no ticks happened. A quick test program, shows timerfd working correctly on my amd64 box: http://www.xmailserver.org/timerfd-test.c [akpm@linux-foundation.org: add sys_timerfd to sys_ni.c] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 13:23:16 +08:00
config TIMERFD
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable timerfd() system call" if EXPERT
signal/timer/event: timerfd core This patch introduces a new system call for timers events delivered though file descriptors. This allows timer event to be used with standard POSIX poll(2), select(2) and read(2). As a consequence of supporting the Linux f_op->poll subsystem, they can be used with epoll(2) too. The system call is defined as: int timerfd(int ufd, int clockid, int flags, const struct itimerspec *utmr); The "ufd" parameter allows for re-use (re-programming) of an existing timerfd w/out going through the close/open cycle (same as signalfd). If "ufd" is -1, s new file descriptor will be created, otherwise the existing "ufd" will be re-programmed. The "clockid" parameter is either CLOCK_MONOTONIC or CLOCK_REALTIME. The time specified in the "utmr->it_value" parameter is the expiry time for the timer. If the TFD_TIMER_ABSTIME flag is set in "flags", this is an absolute time, otherwise it's a relative time. If the time specified in the "utmr->it_interval" is not zero (.tv_sec == 0, tv_nsec == 0), this is the period at which the following ticks should be generated. The "utmr->it_interval" should be set to zero if only one tick is requested. Setting the "utmr->it_value" to zero will disable the timer, or will create a timerfd without the timer enabled. The function returns the new (or same, in case "ufd" is a valid timerfd descriptor) file, or -1 in case of error. As stated before, the timerfd file descriptor supports poll(2), select(2) and epoll(2). When a timer event happened on the timerfd, a POLLIN mask will be returned. The read(2) call can be used, and it will return a u32 variable holding the number of "ticks" that happened on the interface since the last call to read(2). The read(2) call supportes the O_NONBLOCK flag too, and EAGAIN will be returned if no ticks happened. A quick test program, shows timerfd working correctly on my amd64 box: http://www.xmailserver.org/timerfd-test.c [akpm@linux-foundation.org: add sys_timerfd to sys_ni.c] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 13:23:16 +08:00
default y
help
Enable the timerfd() system call that allows to receive timer
events on a file descriptor.
If unsure, say Y.
signal/timer/event: eventfd core This is a very simple and light file descriptor, that can be used as event wait/dispatch by userspace (both wait and dispatch) and by the kernel (dispatch only). It can be used instead of pipe(2) in all cases where those would simply be used to signal events. Their kernel overhead is much lower than pipes, and they do not consume two fds. When used in the kernel, it can offer an fd-bridge to enable, for example, functionalities like KAIO or syslets/threadlets to signal to an fd the completion of certain operations. But more in general, an eventfd can be used by the kernel to signal readiness, in a POSIX poll/select way, of interfaces that would otherwise be incompatible with it. The API is: int eventfd(unsigned int count); The eventfd API accepts an initial "count" parameter, and returns an eventfd fd. It supports poll(2) (POLLIN, POLLOUT, POLLERR), read(2) and write(2). The POLLIN flag is raised when the internal counter is greater than zero. The POLLOUT flag is raised when at least a value of "1" can be written to the internal counter. The POLLERR flag is raised when an overflow in the counter value is detected. The write(2) operation can never overflow the counter, since it blocks (unless O_NONBLOCK is set, in which case -EAGAIN is returned). But the eventfd_signal() function can do it, since it's supposed to not sleep during its operation. The read(2) function reads the __u64 counter value, and reset the internal value to zero. If the value read is equal to (__u64) -1, an overflow happened on the internal counter (due to 2^64 eventfd_signal() posts that has never been retired - unlickely, but possible). The write(2) call writes an __u64 count value, and adds it to the current counter. The eventfd fd supports O_NONBLOCK also. On the kernel side, we have: struct file *eventfd_fget(int fd); int eventfd_signal(struct file *file, unsigned int n); The eventfd_fget() should be called to get a struct file* from an eventfd fd (this is an fget() + check of f_op being an eventfd fops pointer). The kernel can then call eventfd_signal() every time it wants to post an event to userspace. The eventfd_signal() function can be called from any context. An eventfd() simple test and bench is available here: http://www.xmailserver.org/eventfd-bench.c This is the eventfd-based version of pipetest-4 (pipe(2) based): http://www.xmailserver.org/pipetest-4.c Not that performance matters much in the eventfd case, but eventfd-bench shows almost as double as performance than pipetest-4. [akpm@linux-foundation.org: fix i386 build] [akpm@linux-foundation.org: add sys_eventfd to sys_ni.c] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 13:23:19 +08:00
config EVENTFD
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable eventfd() system call" if EXPERT
signal/timer/event: eventfd core This is a very simple and light file descriptor, that can be used as event wait/dispatch by userspace (both wait and dispatch) and by the kernel (dispatch only). It can be used instead of pipe(2) in all cases where those would simply be used to signal events. Their kernel overhead is much lower than pipes, and they do not consume two fds. When used in the kernel, it can offer an fd-bridge to enable, for example, functionalities like KAIO or syslets/threadlets to signal to an fd the completion of certain operations. But more in general, an eventfd can be used by the kernel to signal readiness, in a POSIX poll/select way, of interfaces that would otherwise be incompatible with it. The API is: int eventfd(unsigned int count); The eventfd API accepts an initial "count" parameter, and returns an eventfd fd. It supports poll(2) (POLLIN, POLLOUT, POLLERR), read(2) and write(2). The POLLIN flag is raised when the internal counter is greater than zero. The POLLOUT flag is raised when at least a value of "1" can be written to the internal counter. The POLLERR flag is raised when an overflow in the counter value is detected. The write(2) operation can never overflow the counter, since it blocks (unless O_NONBLOCK is set, in which case -EAGAIN is returned). But the eventfd_signal() function can do it, since it's supposed to not sleep during its operation. The read(2) function reads the __u64 counter value, and reset the internal value to zero. If the value read is equal to (__u64) -1, an overflow happened on the internal counter (due to 2^64 eventfd_signal() posts that has never been retired - unlickely, but possible). The write(2) call writes an __u64 count value, and adds it to the current counter. The eventfd fd supports O_NONBLOCK also. On the kernel side, we have: struct file *eventfd_fget(int fd); int eventfd_signal(struct file *file, unsigned int n); The eventfd_fget() should be called to get a struct file* from an eventfd fd (this is an fget() + check of f_op being an eventfd fops pointer). The kernel can then call eventfd_signal() every time it wants to post an event to userspace. The eventfd_signal() function can be called from any context. An eventfd() simple test and bench is available here: http://www.xmailserver.org/eventfd-bench.c This is the eventfd-based version of pipetest-4 (pipe(2) based): http://www.xmailserver.org/pipetest-4.c Not that performance matters much in the eventfd case, but eventfd-bench shows almost as double as performance than pipetest-4. [akpm@linux-foundation.org: fix i386 build] [akpm@linux-foundation.org: add sys_eventfd to sys_ni.c] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 13:23:19 +08:00
default y
help
Enable the eventfd() system call that allows to receive both
kernel notification (ie. KAIO) or userspace notifications.
If unsure, say Y.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config SHMEM
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Use full shmem filesystem" if EXPERT
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
default y
depends on MMU
help
The shmem is an internal filesystem used to manage shared memory.
It is backed by swap and manages resource limits. It is also exported
to userspace as tmpfs if TMPFS is enabled. Disabling this
option replaces shmem and tmpfs with the much simpler ramfs code,
which may be appropriate on small systems without swap.
Configure out AIO support This patchs adds the CONFIG_AIO option which allows to remove support for asynchronous I/O operations, that are not necessarly used by applications, particularly on embedded devices. As this is a size-reduction option, it depends on CONFIG_EMBEDDED. It allows to save ~7 kilobytes of kernel code/data: text data bss dec hex filename 1115067 119180 217088 1451335 162547 vmlinux 1108025 119048 217088 1444161 160941 vmlinux.new -7042 -132 0 -7174 -1C06 +/- This patch has been originally written by Matt Mackall <mpm@selenic.com>, and is part of the Linux Tiny project. [randy.dunlap@oracle.com: build fix] Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Zach Brown <zach.brown@oracle.com> Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:05:12 +08:00
config AIO
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable AIO support" if EXPERT
Configure out AIO support This patchs adds the CONFIG_AIO option which allows to remove support for asynchronous I/O operations, that are not necessarly used by applications, particularly on embedded devices. As this is a size-reduction option, it depends on CONFIG_EMBEDDED. It allows to save ~7 kilobytes of kernel code/data: text data bss dec hex filename 1115067 119180 217088 1451335 162547 vmlinux 1108025 119048 217088 1444161 160941 vmlinux.new -7042 -132 0 -7174 -1C06 +/- This patch has been originally written by Matt Mackall <mpm@selenic.com>, and is part of the Linux Tiny project. [randy.dunlap@oracle.com: build fix] Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Zach Brown <zach.brown@oracle.com> Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:05:12 +08:00
default y
help
This option enables POSIX asynchronous I/O which may by used
init/Kconfig: re-order CONFIG_EXPERT options to fix menuconfig display The kconfig language requires that dependent options all follow the menuconfig symbol in order to be collapsed below it. Recently some hidden options were added below the EXPERT menuconfig, but did not depend on EXPERT (because hidden options can't). This broke the display. So re-order all these options, and while we're here stick the PCI quirks under the EXPERT menu (since it isn't sitting with any related options). Before this commit, we get: [*] Configure standard kernel features (expert users) ---> [ ] Sysctl syscall support [*] Load all symbols for debugging/ksymoops ... [ ] Embedded system Now we get the older (and correct) behavior: [*] Configure standard kernel features (expert users) ---> [ ] Embedded system And if you go into the expert menu you get the expert options: [ ] Sysctl syscall support [*] Load all symbols for debugging/ksymoops ... Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01 06:28:45 +08:00
by some high performance threaded applications. Disabling
this option saves about 7k.
Add io_uring IO interface The submission queue (SQ) and completion queue (CQ) rings are shared between the application and the kernel. This eliminates the need to copy data back and forth to submit and complete IO. IO submissions use the io_uring_sqe data structure, and completions are generated in the form of io_uring_cqe data structures. The SQ ring is an index into the io_uring_sqe array, which makes it possible to submit a batch of IOs without them being contiguous in the ring. The CQ ring is always contiguous, as completion events are inherently unordered, and hence any io_uring_cqe entry can point back to an arbitrary submission. Two new system calls are added for this: io_uring_setup(entries, params) Sets up an io_uring instance for doing async IO. On success, returns a file descriptor that the application can mmap to gain access to the SQ ring, CQ ring, and io_uring_sqes. io_uring_enter(fd, to_submit, min_complete, flags, sigset, sigsetsize) Initiates IO against the rings mapped to this fd, or waits for them to complete, or both. The behavior is controlled by the parameters passed in. If 'to_submit' is non-zero, then we'll try and submit new IO. If IORING_ENTER_GETEVENTS is set, the kernel will wait for 'min_complete' events, if they aren't already available. It's valid to set IORING_ENTER_GETEVENTS and 'min_complete' == 0 at the same time, this allows the kernel to return already completed events without waiting for them. This is useful only for polling, as for IRQ driven IO, the application can just check the CQ ring without entering the kernel. With this setup, it's possible to do async IO with a single system call. Future developments will enable polled IO with this interface, and polled submission as well. The latter will enable an application to do IO without doing ANY system calls at all. For IRQ driven IO, an application only needs to enter the kernel for completions if it wants to wait for them to occur. Each io_uring is backed by a workqueue, to support buffered async IO as well. We will only punt to an async context if the command would need to wait for IO on the device side. Any data that can be accessed directly in the page cache is done inline. This avoids the slowness issue of usual threadpools, since cached data is accessed as quickly as a sync interface. Sample application: http://git.kernel.dk/cgit/fio/plain/t/io_uring.c Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-08 01:46:33 +08:00
config IO_URING
bool "Enable IO uring support" if EXPERT
io_uring: replace workqueue usage with io-wq Drop various work-arounds we have for workqueues: - We no longer need the async_list for tracking sequential IO. - We don't have to maintain our own mm tracking/setting. - We don't need a separate workqueue for buffered writes. This didn't even work that well to begin with, as it was suboptimal for multiple buffered writers on multiple files. - We can properly cancel pending interruptible work. This fixes deadlocks with particularly socket IO, where we cannot cancel them when the io_uring is closed. Hence the ring will wait forever for these requests to complete, which may never happen. This is different from disk IO where we know requests will complete in a finite amount of time. - Due to being able to cancel work interruptible work that is already running, we can implement file table support for work. We need that for supporting system calls that add to a process file table. - It gets us one step closer to adding async support for any system call. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-24 21:25:42 +08:00
select IO_WQ
Add io_uring IO interface The submission queue (SQ) and completion queue (CQ) rings are shared between the application and the kernel. This eliminates the need to copy data back and forth to submit and complete IO. IO submissions use the io_uring_sqe data structure, and completions are generated in the form of io_uring_cqe data structures. The SQ ring is an index into the io_uring_sqe array, which makes it possible to submit a batch of IOs without them being contiguous in the ring. The CQ ring is always contiguous, as completion events are inherently unordered, and hence any io_uring_cqe entry can point back to an arbitrary submission. Two new system calls are added for this: io_uring_setup(entries, params) Sets up an io_uring instance for doing async IO. On success, returns a file descriptor that the application can mmap to gain access to the SQ ring, CQ ring, and io_uring_sqes. io_uring_enter(fd, to_submit, min_complete, flags, sigset, sigsetsize) Initiates IO against the rings mapped to this fd, or waits for them to complete, or both. The behavior is controlled by the parameters passed in. If 'to_submit' is non-zero, then we'll try and submit new IO. If IORING_ENTER_GETEVENTS is set, the kernel will wait for 'min_complete' events, if they aren't already available. It's valid to set IORING_ENTER_GETEVENTS and 'min_complete' == 0 at the same time, this allows the kernel to return already completed events without waiting for them. This is useful only for polling, as for IRQ driven IO, the application can just check the CQ ring without entering the kernel. With this setup, it's possible to do async IO with a single system call. Future developments will enable polled IO with this interface, and polled submission as well. The latter will enable an application to do IO without doing ANY system calls at all. For IRQ driven IO, an application only needs to enter the kernel for completions if it wants to wait for them to occur. Each io_uring is backed by a workqueue, to support buffered async IO as well. We will only punt to an async context if the command would need to wait for IO on the device side. Any data that can be accessed directly in the page cache is done inline. This avoids the slowness issue of usual threadpools, since cached data is accessed as quickly as a sync interface. Sample application: http://git.kernel.dk/cgit/fio/plain/t/io_uring.c Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-08 01:46:33 +08:00
default y
help
This option enables support for the io_uring interface, enabling
applications to submit and complete IO through submission and
completion rings that are shared between the kernel and application.
mm: Support compiling out madvise and fadvise Many embedded systems will not need these syscalls, and omitting them saves space. Add a new EXPERT config option CONFIG_ADVISE_SYSCALLS (default y) to support compiling them out. bloat-o-meter: add/remove: 0/3 grow/shrink: 0/0 up/down: 0/-2250 (-2250) function old new delta sys_fadvise64 57 - -57 sys_fadvise64_64 691 - -691 sys_madvise 1502 - -1502 Signed-off-by: Josh Triplett <josh@joshtriplett.org>
2014-08-18 08:41:09 +08:00
config ADVISE_SYSCALLS
bool "Enable madvise/fadvise syscalls" if EXPERT
default y
help
This option enables the madvise and fadvise syscalls, used by
applications to advise the kernel about their future memory or file
usage, improving performance. If building an embedded system where no
applications use these syscalls, you can disable this option to save
space.
userfaultfd: wp: add WP pagetable tracking to x86 Accurate userfaultfd WP tracking is possible by tracking exactly which virtual memory ranges were writeprotected by userland. We can't relay only on the RW bit of the mapped pagetable because that information is destroyed by fork() or KSM or swap. If we were to relay on that, we'd need to stay on the safe side and generate false positive wp faults for every swapped out page. [peterx@redhat.com: append _PAGE_UFD_WP to _PAGE_CHG_MASK] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jerome Glisse <jglisse@redhat.com> Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Bobby Powers <bobbypowers@gmail.com> Cc: Brian Geffon <bgeffon@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Denis Plotnikov <dplotnikov@virtuozzo.com> Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Martin Cracauer <cracauer@cons.org> Cc: Marty McFadden <mcfadden8@llnl.gov> Cc: Maya Gokhale <gokhale2@llnl.gov> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@fb.com> Link: http://lkml.kernel.org/r/20200220163112.11409-4-peterx@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07 11:05:33 +08:00
config HAVE_ARCH_USERFAULTFD_WP
bool
help
Arch has userfaultfd write protection support
sys_membarrier(): system-wide memory barrier (generic, x86) Here is an implementation of a new system call, sys_membarrier(), which executes a memory barrier on all threads running on the system. It is implemented by calling synchronize_sched(). It can be used to distribute the cost of user-space memory barriers asymmetrically by transforming pairs of memory barriers into pairs consisting of sys_membarrier() and a compiler barrier. For synchronization primitives that distinguish between read-side and write-side (e.g. userspace RCU [1], rwlocks), the read-side can be accelerated significantly by moving the bulk of the memory barrier overhead to the write-side. The existing applications of which I am aware that would be improved by this system call are as follows: * Through Userspace RCU library (http://urcu.so) - DNS server (Knot DNS) https://www.knot-dns.cz/ - Network sniffer (http://netsniff-ng.org/) - Distributed object storage (https://sheepdog.github.io/sheepdog/) - User-space tracing (http://lttng.org) - Network storage system (https://www.gluster.org/) - Virtual routers (https://events.linuxfoundation.org/sites/events/files/slides/DPDK_RCU_0MQ.pdf) - Financial software (https://lkml.org/lkml/2015/3/23/189) Those projects use RCU in userspace to increase read-side speed and scalability compared to locking. Especially in the case of RCU used by libraries, sys_membarrier can speed up the read-side by moving the bulk of the memory barrier cost to synchronize_rcu(). * Direct users of sys_membarrier - core dotnet garbage collector (https://github.com/dotnet/coreclr/issues/198) Microsoft core dotnet GC developers are planning to use the mprotect() side-effect of issuing memory barriers through IPIs as a way to implement Windows FlushProcessWriteBuffers() on Linux. They are referring to sys_membarrier in their github thread, specifically stating that sys_membarrier() is what they are looking for. To explain the benefit of this scheme, let's introduce two example threads: Thread A (non-frequent, e.g. executing liburcu synchronize_rcu()) Thread B (frequent, e.g. executing liburcu rcu_read_lock()/rcu_read_unlock()) In a scheme where all smp_mb() in thread A are ordering memory accesses with respect to smp_mb() present in Thread B, we can change each smp_mb() within Thread A into calls to sys_membarrier() and each smp_mb() within Thread B into compiler barriers "barrier()". Before the change, we had, for each smp_mb() pairs: Thread A Thread B previous mem accesses previous mem accesses smp_mb() smp_mb() following mem accesses following mem accesses After the change, these pairs become: Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses As we can see, there are two possible scenarios: either Thread B memory accesses do not happen concurrently with Thread A accesses (1), or they do (2). 1) Non-concurrent Thread A vs Thread B accesses: Thread A Thread B prev mem accesses sys_membarrier() follow mem accesses prev mem accesses barrier() follow mem accesses In this case, thread B accesses will be weakly ordered. This is OK, because at that point, thread A is not particularly interested in ordering them with respect to its own accesses. 2) Concurrent Thread A vs Thread B accesses Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses In this case, thread B accesses, which are ensured to be in program order thanks to the compiler barrier, will be "upgraded" to full smp_mb() by synchronize_sched(). * Benchmarks On Intel Xeon E5405 (8 cores) (one thread is calling sys_membarrier, the other 7 threads are busy looping) 1000 non-expedited sys_membarrier calls in 33s =3D 33 milliseconds/call. * User-space user of this system call: Userspace RCU library Both the signal-based and the sys_membarrier userspace RCU schemes permit us to remove the memory barrier from the userspace RCU rcu_read_lock() and rcu_read_unlock() primitives, thus significantly accelerating them. These memory barriers are replaced by compiler barriers on the read-side, and all matching memory barriers on the write-side are turned into an invocation of a memory barrier on all active threads in the process. By letting the kernel perform this synchronization rather than dumbly sending a signal to every process threads (as we currently do), we diminish the number of unnecessary wake ups and only issue the memory barriers on active threads. Non-running threads do not need to execute such barrier anyway, because these are implied by the scheduler context switches. Results in liburcu: Operations in 10s, 6 readers, 2 writers: memory barriers in reader: 1701557485 reads, 2202847 writes signal-based scheme: 9830061167 reads, 6700 writes sys_membarrier: 9952759104 reads, 425 writes sys_membarrier (dyn. check): 7970328887 reads, 425 writes The dynamic sys_membarrier availability check adds some overhead to the read-side compared to the signal-based scheme, but besides that, sys_membarrier slightly outperforms the signal-based scheme. However, this non-expedited sys_membarrier implementation has a much slower grace period than signal and memory barrier schemes. Besides diminishing the number of wake-ups, one major advantage of the membarrier system call over the signal-based scheme is that it does not need to reserve a signal. This plays much more nicely with libraries, and with processes injected into for tracing purposes, for which we cannot expect that signals will be unused by the application. An expedited version of this system call can be added later on to speed up the grace period. Its implementation will likely depend on reading the cpu_curr()->mm without holding each CPU's rq lock. This patch adds the system call to x86 and to asm-generic. [1] http://urcu.so membarrier(2) man page: MEMBARRIER(2) Linux Programmer's Manual MEMBARRIER(2) NAME membarrier - issue memory barriers on a set of threads SYNOPSIS #include <linux/membarrier.h> int membarrier(int cmd, int flags); DESCRIPTION The cmd argument is one of the following: MEMBARRIER_CMD_QUERY Query the set of supported commands. It returns a bitmask of supported commands. MEMBARRIER_CMD_SHARED Execute a memory barrier on all threads running on the system. Upon return from system call, the caller thread is ensured that all running threads have passed through a state where all memory accesses to user-space addresses match program order between entry to and return from the system call (non-running threads are de facto in such a state). This covers threads from all pro=E2=80=90 cesses running on the system. This command returns 0. The flags argument needs to be 0. For future extensions. All memory accesses performed in program order from each targeted thread is guaranteed to be ordered with respect to sys_membarrier(). If we use the semantic "barrier()" to represent a compiler barrier forcing memory accesses to be performed in program order across the barrier, and smp_mb() to represent explicit memory barriers forcing full memory ordering across the barrier, we have the following ordering table for each pair of barrier(), sys_membarrier() and smp_mb(): The pair ordering is detailed as (O: ordered, X: not ordered): barrier() smp_mb() sys_membarrier() barrier() X X O smp_mb() X O O sys_membarrier() O O O RETURN VALUE On success, these system calls return zero. On error, -1 is returned, and errno is set appropriately. For a given command, with flags argument set to 0, this system call is guaranteed to always return the same value until reboot. ERRORS ENOSYS System call is not implemented. EINVAL Invalid arguments. Linux 2015-04-15 MEMBARRIER(2) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nicholas Miell <nmiell@comcast.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Howells <dhowells@redhat.com> Cc: Pranith Kumar <bobby.prani@gmail.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-12 04:07:39 +08:00
config MEMBARRIER
bool "Enable membarrier() system call" if EXPERT
default y
help
Enable the membarrier() system call that allows issuing memory
barriers across all running threads, which can be used to distribute
the cost of user-space memory barriers asymmetrically by transforming
pairs of memory barriers into pairs consisting of membarrier() and a
compiler barrier.
If unsure, say Y.
EXPERT Kconfig menu: fix broken EXPERT menu Clean up the EXPERT menu (yet again). Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since they already depend on EXPERT. Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu list since they do not depend on EXPERT and were breaking the continuity of that menu list. Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu. This separates the kernel services from the build options. This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu (https://lkml.org/lkml/2017/11/2/907). Link: http://lkml.kernel.org/r/72e4465a-a5ff-cb3c-1a90-11aa4861b161@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> [BPF] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18 07:31:47 +08:00
config KALLSYMS
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
bool "Load all symbols for debugging/ksymoops" if EXPERT
default y
help
Say Y here to let the kernel print out symbolic crash information and
symbolic stack backtraces. This increases the size of the kernel
somewhat, as all symbols have to be loaded into the kernel image.
EXPERT Kconfig menu: fix broken EXPERT menu Clean up the EXPERT menu (yet again). Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since they already depend on EXPERT. Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu list since they do not depend on EXPERT and were breaking the continuity of that menu list. Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu. This separates the kernel services from the build options. This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu (https://lkml.org/lkml/2017/11/2/907). Link: http://lkml.kernel.org/r/72e4465a-a5ff-cb3c-1a90-11aa4861b161@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> [BPF] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18 07:31:47 +08:00
config KALLSYMS_ALL
bool "Include all symbols in kallsyms"
depends on DEBUG_KERNEL && KALLSYMS
help
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
Normally kallsyms only contains the symbols of functions for nicer
OOPS messages and backtraces (i.e., symbols from the text and inittext
sections). This is sufficient for most cases. And only in very rare
cases (e.g., when a debugger is used) all symbols are required (e.g.,
names of variables from the data sections, etc).
EXPERT Kconfig menu: fix broken EXPERT menu Clean up the EXPERT menu (yet again). Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since they already depend on EXPERT. Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu list since they do not depend on EXPERT and were breaking the continuity of that menu list. Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu. This separates the kernel services from the build options. This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu (https://lkml.org/lkml/2017/11/2/907). Link: http://lkml.kernel.org/r/72e4465a-a5ff-cb3c-1a90-11aa4861b161@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> [BPF] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18 07:31:47 +08:00
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
This option makes sure that all symbols are loaded into the kernel
image (i.e., symbols from all sections) in cost of increased kernel
size (depending on the kernel configuration, it may be 300KiB or
something like this).
EXPERT Kconfig menu: fix broken EXPERT menu Clean up the EXPERT menu (yet again). Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since they already depend on EXPERT. Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu list since they do not depend on EXPERT and were breaking the continuity of that menu list. Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu. This separates the kernel services from the build options. This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu (https://lkml.org/lkml/2017/11/2/907). Link: http://lkml.kernel.org/r/72e4465a-a5ff-cb3c-1a90-11aa4861b161@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> [BPF] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18 07:31:47 +08:00
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
Say N unless you really need all symbols.
EXPERT Kconfig menu: fix broken EXPERT menu Clean up the EXPERT menu (yet again). Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since they already depend on EXPERT. Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu list since they do not depend on EXPERT and were breaking the continuity of that menu list. Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu. This separates the kernel services from the build options. This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu (https://lkml.org/lkml/2017/11/2/907). Link: http://lkml.kernel.org/r/72e4465a-a5ff-cb3c-1a90-11aa4861b161@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> [BPF] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18 07:31:47 +08:00
config KALLSYMS_ABSOLUTE_PERCPU
bool
depends on KALLSYMS
default X86_64 && SMP
config KALLSYMS_BASE_RELATIVE
bool
depends on KALLSYMS
treewide: simplify Kconfig dependencies for removed archs A lot of Kconfig symbols have architecture specific dependencies. In those cases that depend on architectures we have already removed, they can be omitted. Acked-by: Kalle Valo <kvalo@codeaurora.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-08 06:30:54 +08:00
default !IA64
EXPERT Kconfig menu: fix broken EXPERT menu Clean up the EXPERT menu (yet again). Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since they already depend on EXPERT. Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu list since they do not depend on EXPERT and were breaking the continuity of that menu list. Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu. This separates the kernel services from the build options. This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu (https://lkml.org/lkml/2017/11/2/907). Link: http://lkml.kernel.org/r/72e4465a-a5ff-cb3c-1a90-11aa4861b161@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> [BPF] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18 07:31:47 +08:00
help
Instead of emitting them as absolute values in the native word size,
emit the symbol references in the kallsyms table as 32-bit entries,
each containing a relative value in the range [base, base + U32_MAX]
or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either
an absolute value in the range [0, S32_MAX] or a relative value in the
range [base, base + S32_MAX], where base is the lowest relative symbol
address encountered in the image.
On 64-bit builds, this reduces the size of the address table by 50%,
but more importantly, it results in entries whose values are build
time constants, and no relocation pass is required at runtime to fix
up the entries based on the runtime load address of the kernel.
# end of the "standard kernel features (expert users)" menu
# syscall, maps, verifier
bpf: Introduce BPF_PROG_TYPE_LSM Introduce types and configs for bpf programs that can be attached to LSM hooks. The programs can be enabled by the config option CONFIG_BPF_LSM. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Brendan Jackman <jackmanb@google.com> Reviewed-by: Florent Revest <revest@google.com> Reviewed-by: Thomas Garnier <thgarnie@google.com> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: James Morris <jamorris@linux.microsoft.com> Link: https://lore.kernel.org/bpf/20200329004356.27286-2-kpsingh@chromium.org
2020-03-29 08:43:49 +08:00
config BPF_LSM
bool "LSM Instrumentation with BPF"
bpf, lsm: Make BPF_LSM depend on BPF_EVENTS LSM and tracing programs share their helpers with bpf_tracing_func_proto which is only defined (in bpf_trace.c) when BPF_EVENTS is enabled. Instead of adding __weak symbol, make BPF_LSM depend on BPF_EVENTS so that both tracing and LSM programs can actually share helpers. Fixes: fc611f47f218 ("bpf: Introduce BPF_PROG_TYPE_LSM") Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200330204059.13024-1-kpsingh@chromium.org
2020-03-31 04:40:59 +08:00
depends on BPF_EVENTS
bpf: Introduce BPF_PROG_TYPE_LSM Introduce types and configs for bpf programs that can be attached to LSM hooks. The programs can be enabled by the config option CONFIG_BPF_LSM. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Brendan Jackman <jackmanb@google.com> Reviewed-by: Florent Revest <revest@google.com> Reviewed-by: Thomas Garnier <thgarnie@google.com> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: James Morris <jamorris@linux.microsoft.com> Link: https://lore.kernel.org/bpf/20200329004356.27286-2-kpsingh@chromium.org
2020-03-29 08:43:49 +08:00
depends on BPF_SYSCALL
depends on SECURITY
depends on BPF_JIT
help
Enables instrumentation of the security hooks with eBPF programs for
implementing dynamic MAC and Audit Policies.
If you are unsure how to answer this question, answer N.
EXPERT Kconfig menu: fix broken EXPERT menu Clean up the EXPERT menu (yet again). Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since they already depend on EXPERT. Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu list since they do not depend on EXPERT and were breaking the continuity of that menu list. Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu. This separates the kernel services from the build options. This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu (https://lkml.org/lkml/2017/11/2/907). Link: http://lkml.kernel.org/r/72e4465a-a5ff-cb3c-1a90-11aa4861b161@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> [BPF] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18 07:31:47 +08:00
config BPF_SYSCALL
bool "Enable bpf() system call"
select BPF
bpf: enable stackmap with build_id in nmi context Currently, we cannot parse build_id in nmi context because of up_read(&current->mm->mmap_sem), this makes stackmap with build_id less useful. This patch enables parsing build_id in nmi by putting the up_read() call in irq_work. To avoid memory allocation in nmi context, we use per cpu variable for the irq_work. As a result, only one irq_work per cpu is allowed. If the irq_work is in-use, we fallback to only report ips. Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-08 01:50:48 +08:00
select IRQ_WORK
EXPERT Kconfig menu: fix broken EXPERT menu Clean up the EXPERT menu (yet again). Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since they already depend on EXPERT. Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu list since they do not depend on EXPERT and were breaking the continuity of that menu list. Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu. This separates the kernel services from the build options. This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu (https://lkml.org/lkml/2017/11/2/907). Link: http://lkml.kernel.org/r/72e4465a-a5ff-cb3c-1a90-11aa4861b161@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> [BPF] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18 07:31:47 +08:00
default n
help
Enable the bpf() system call that allows to manipulate eBPF
programs and maps via file descriptors.
bpf, x86, arm64: Enable jit by default when not built as always-on After Spectre 2 fix via 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config") most major distros use BPF_JIT_ALWAYS_ON configuration these days which compiles out the BPF interpreter entirely and always enables the JIT. Also given recent fix in e1608f3fa857 ("bpf: Avoid setting bpf insns pages read-only when prog is jited"), we additionally avoid fragmenting the direct map for the BPF insns pages sitting in the general data heap since they are not used during execution. Latter is only needed when run through the interpreter. Since both x86 and arm64 JITs have seen a lot of exposure over the years, are generally most up to date and maintained, there is more downside in !BPF_JIT_ALWAYS_ON configurations to have the interpreter enabled by default rather than the JIT. Add a ARCH_WANT_DEFAULT_BPF_JIT config which archs can use to set the bpf_jit_{enable,kallsyms} to 1. Back in the days the bpf_jit_kallsyms knob was set to 0 by default since major distros still had /proc/kallsyms addresses exposed to unprivileged user space which is not the case anymore. Hence both knobs are set via BPF_JIT_DEFAULT_ON which is set to 'y' in case of BPF_JIT_ALWAYS_ON or ARCH_WANT_DEFAULT_BPF_JIT. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/f78ad24795c2966efcc2ee19025fa3459f622185.1575903816.git.daniel@iogearbox.net
2019-12-09 23:08:03 +08:00
config ARCH_WANT_DEFAULT_BPF_JIT
bool
bpf: introduce BPF_JIT_ALWAYS_ON config The BPF interpreter has been used as part of the spectre 2 attack CVE-2017-5715. A quote from goolge project zero blog: "At this point, it would normally be necessary to locate gadgets in the host kernel code that can be used to actually leak data by reading from an attacker-controlled location, shifting and masking the result appropriately and then using the result of that as offset to an attacker-controlled address for a load. But piecing gadgets together and figuring out which ones work in a speculation context seems annoying. So instead, we decided to use the eBPF interpreter, which is built into the host kernel - while there is no legitimate way to invoke it from inside a VM, the presence of the code in the host kernel's text section is sufficient to make it usable for the attack, just like with ordinary ROP gadgets." To make attacker job harder introduce BPF_JIT_ALWAYS_ON config option that removes interpreter from the kernel in favor of JIT-only mode. So far eBPF JIT is supported by: x64, arm64, arm32, sparc64, s390, powerpc64, mips64 The start of JITed program is randomized and code page is marked as read-only. In addition "constant blinding" can be turned on with net.core.bpf_jit_harden v2->v3: - move __bpf_prog_ret0 under ifdef (Daniel) v1->v2: - fix init order, test_bpf and cBPF (Daniel's feedback) - fix offloaded bpf (Jakub's feedback) - add 'return 0' dummy in case something can invoke prog->bpf_func - retarget bpf tree. For bpf-next the patch would need one extra hunk. It will be sent when the trees are merged back to net-next Considered doing: int bpf_jit_enable __read_mostly = BPF_EBPF_JIT_DEFAULT; but it seems better to land the patch as-is and in bpf-next remove bpf_jit_enable global variable from all JITs, consolidate in one place and remove this jit_init() function. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-10 02:04:29 +08:00
config BPF_JIT_ALWAYS_ON
bool "Permanently enable BPF JIT and remove BPF interpreter"
depends on BPF_SYSCALL && HAVE_EBPF_JIT && BPF_JIT
help
Enables BPF JIT and removes BPF interpreter to avoid
speculative execution of BPF instructions by the interpreter
bpf, x86, arm64: Enable jit by default when not built as always-on After Spectre 2 fix via 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config") most major distros use BPF_JIT_ALWAYS_ON configuration these days which compiles out the BPF interpreter entirely and always enables the JIT. Also given recent fix in e1608f3fa857 ("bpf: Avoid setting bpf insns pages read-only when prog is jited"), we additionally avoid fragmenting the direct map for the BPF insns pages sitting in the general data heap since they are not used during execution. Latter is only needed when run through the interpreter. Since both x86 and arm64 JITs have seen a lot of exposure over the years, are generally most up to date and maintained, there is more downside in !BPF_JIT_ALWAYS_ON configurations to have the interpreter enabled by default rather than the JIT. Add a ARCH_WANT_DEFAULT_BPF_JIT config which archs can use to set the bpf_jit_{enable,kallsyms} to 1. Back in the days the bpf_jit_kallsyms knob was set to 0 by default since major distros still had /proc/kallsyms addresses exposed to unprivileged user space which is not the case anymore. Hence both knobs are set via BPF_JIT_DEFAULT_ON which is set to 'y' in case of BPF_JIT_ALWAYS_ON or ARCH_WANT_DEFAULT_BPF_JIT. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/f78ad24795c2966efcc2ee19025fa3459f622185.1575903816.git.daniel@iogearbox.net
2019-12-09 23:08:03 +08:00
config BPF_JIT_DEFAULT_ON
def_bool ARCH_WANT_DEFAULT_BPF_JIT || BPF_JIT_ALWAYS_ON
depends on HAVE_EBPF_JIT && BPF_JIT
EXPERT Kconfig menu: fix broken EXPERT menu Clean up the EXPERT menu (yet again). Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since they already depend on EXPERT. Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu list since they do not depend on EXPERT and were breaking the continuity of that menu list. Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu. This separates the kernel services from the build options. This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu (https://lkml.org/lkml/2017/11/2/907). Link: http://lkml.kernel.org/r/72e4465a-a5ff-cb3c-1a90-11aa4861b161@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> [BPF] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18 07:31:47 +08:00
config USERFAULTFD
bool "Enable userfaultfd() system call"
depends on MMU
help
Enable the userfaultfd() system call that allows to intercept and
handle page faults in userland.
powerpc, membarrier: Skip memory barrier in switch_mm() Allow PowerPC to skip the full memory barrier in switch_mm(), and only issue the barrier when scheduling into a task belonging to a process that has registered to use expedited private. Threads targeting the same VM but which belong to different thread groups is a tricky case. It has a few consequences: It turns out that we cannot rely on get_nr_threads(p) to count the number of threads using a VM. We can use (atomic_read(&mm->mm_users) == 1 && get_nr_threads(p) == 1) instead to skip the synchronize_sched() for cases where the VM only has a single user, and that user only has a single thread. It also turns out that we cannot use for_each_thread() to set thread flags in all threads using a VM, as it only iterates on the thread group. Therefore, test the membarrier state variable directly rather than relying on thread flags. This means membarrier_register_private_expedited() needs to set the MEMBARRIER_STATE_PRIVATE_EXPEDITED flag, issue synchronize_sched(), and only then set MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY which allows private expedited membarrier commands to succeed. membarrier_arch_switch_mm() now tests for the MEMBARRIER_STATE_PRIVATE_EXPEDITED flag. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Andrew Hunter <ahh@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Avi Kivity <avi@scylladb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dave Watson <davejwatson@fb.com> Cc: David Sehr <sehr@google.com> Cc: Greg Hackmann <ghackmann@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maged Michael <maged.michael@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20180129202020.8515-3-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-30 04:20:11 +08:00
config ARCH_HAS_MEMBARRIER_CALLBACKS
bool
membarrier: Provide core serializing command, *_SYNC_CORE Provide core serializing membarrier command to support memory reclaim by JIT. Each architecture needs to explicitly opt into that support by documenting in their architecture code how they provide the core serializing instructions required when returning from the membarrier IPI, and after the scheduler has updated the curr->mm pointer (before going back to user-space). They should then select ARCH_HAS_MEMBARRIER_SYNC_CORE to enable support for that command on their architecture. Architectures selecting this feature need to either document that they issue core serializing instructions when returning to user-space, or implement their architecture-specific sync_core_before_usermode(). Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Andrew Hunter <ahh@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Avi Kivity <avi@scylladb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dave Watson <davejwatson@fb.com> Cc: David Sehr <sehr@google.com> Cc: Greg Hackmann <ghackmann@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maged Michael <maged.michael@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/20180129202020.8515-9-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-30 04:20:17 +08:00
config ARCH_HAS_MEMBARRIER_SYNC_CORE
bool
rseq: Introduce restartable sequences system call Expose a new system call allowing each thread to register one userspace memory area to be used as an ABI between kernel and user-space for two purposes: user-space restartable sequences and quick access to read the current CPU number value from user-space. * Restartable sequences (per-cpu atomics) Restartables sequences allow user-space to perform update operations on per-cpu data without requiring heavy-weight atomic operations. The restartable critical sections (percpu atomics) work has been started by Paul Turner and Andrew Hunter. It lets the kernel handle restart of critical sections. [1] [2] The re-implementation proposed here brings a few simplifications to the ABI which facilitates porting to other architectures and speeds up the user-space fast path. Here are benchmarks of various rseq use-cases. Test hardware: arm32: ARMv7 Processor rev 4 (v7l) "Cubietruck", 2-core x86-64: Intel E5-2630 v3@2.40GHz, 16-core, hyperthreading The following benchmarks were all performed on a single thread. * Per-CPU statistic counter increment getcpu+atomic (ns/op) rseq (ns/op) speedup arm32: 344.0 31.4 11.0 x86-64: 15.3 2.0 7.7 * LTTng-UST: write event 32-bit header, 32-bit payload into tracer per-cpu buffer getcpu+atomic (ns/op) rseq (ns/op) speedup arm32: 2502.0 2250.0 1.1 x86-64: 117.4 98.0 1.2 * liburcu percpu: lock-unlock pair, dereference, read/compare word getcpu+atomic (ns/op) rseq (ns/op) speedup arm32: 751.0 128.5 5.8 x86-64: 53.4 28.6 1.9 * jemalloc memory allocator adapted to use rseq Using rseq with per-cpu memory pools in jemalloc at Facebook (based on rseq 2016 implementation): The production workload response-time has 1-2% gain avg. latency, and the P99 overall latency drops by 2-3%. * Reading the current CPU number Speeding up reading the current CPU number on which the caller thread is running is done by keeping the current CPU number up do date within the cpu_id field of the memory area registered by the thread. This is done by making scheduler preemption set the TIF_NOTIFY_RESUME flag on the current thread. Upon return to user-space, a notify-resume handler updates the current CPU value within the registered user-space memory area. User-space can then read the current CPU number directly from memory. Keeping the current cpu id in a memory area shared between kernel and user-space is an improvement over current mechanisms available to read the current CPU number, which has the following benefits over alternative approaches: - 35x speedup on ARM vs system call through glibc - 20x speedup on x86 compared to calling glibc, which calls vdso executing a "lsl" instruction, - 14x speedup on x86 compared to inlined "lsl" instruction, - Unlike vdso approaches, this cpu_id value can be read from an inline assembly, which makes it a useful building block for restartable sequences. - The approach of reading the cpu id through memory mapping shared between kernel and user-space is portable (e.g. ARM), which is not the case for the lsl-based x86 vdso. On x86, yet another possible approach would be to use the gs segment selector to point to user-space per-cpu data. This approach performs similarly to the cpu id cache, but it has two disadvantages: it is not portable, and it is incompatible with existing applications already using the gs segment selector for other purposes. Benchmarking various approaches for reading the current CPU number: ARMv7 Processor rev 4 (v7l) Machine model: Cubietruck - Baseline (empty loop): 8.4 ns - Read CPU from rseq cpu_id: 16.7 ns - Read CPU from rseq cpu_id (lazy register): 19.8 ns - glibc 2.19-0ubuntu6.6 getcpu: 301.8 ns - getcpu system call: 234.9 ns x86-64 Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz: - Baseline (empty loop): 0.8 ns - Read CPU from rseq cpu_id: 0.8 ns - Read CPU from rseq cpu_id (lazy register): 0.8 ns - Read using gs segment selector: 0.8 ns - "lsl" inline assembly: 13.0 ns - glibc 2.19-0ubuntu6 getcpu: 16.6 ns - getcpu system call: 53.9 ns - Speed (benchmark taken on v8 of patchset) Running 10 runs of hackbench -l 100000 seems to indicate, contrary to expectations, that enabling CONFIG_RSEQ slightly accelerates the scheduler: Configuration: 2 sockets * 8-core Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz (directly on hardware, hyperthreading disabled in BIOS, energy saving disabled in BIOS, turboboost disabled in BIOS, cpuidle.off=1 kernel parameter), with a Linux v4.6 defconfig+localyesconfig, restartable sequences series applied. * CONFIG_RSEQ=n avg.: 41.37 s std.dev.: 0.36 s * CONFIG_RSEQ=y avg.: 40.46 s std.dev.: 0.33 s - Size On x86-64, between CONFIG_RSEQ=n/y, the text size increase of vmlinux is 567 bytes, and the data size increase of vmlinux is 5696 bytes. [1] https://lwn.net/Articles/650333/ [2] http://www.linuxplumbersconf.org/2013/ocw/system/presentations/1695/original/LPC%20-%20PerCpu%20Atomics.pdf Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Joel Fernandes <joelaf@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Watson <davejwatson@fb.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Chris Lameter <cl@linux.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Andrew Hunter <ahh@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Maurer <bmaurer@fb.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-api@vger.kernel.org Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20151027235635.16059.11630.stgit@pjt-glaptop.roam.corp.google.com Link: http://lkml.kernel.org/r/20150624222609.6116.86035.stgit@kitami.mtv.corp.google.com Link: https://lkml.kernel.org/r/20180602124408.8430-3-mathieu.desnoyers@efficios.com
2018-06-02 20:43:54 +08:00
config RSEQ
bool "Enable rseq() system call" if EXPERT
default y
depends on HAVE_RSEQ
select MEMBARRIER
help
Enable the restartable sequences system call. It provides a
user-space cache for the current CPU number value, which
speeds up getting the current CPU number from user-space,
as well as an ABI to speed up user-space operations on
per-CPU data.
If unsure, say Y.
config DEBUG_RSEQ
default n
bool "Enabled debugging of rseq() system call" if EXPERT
depends on RSEQ && DEBUG_KERNEL
help
Enable extra debugging checks for the rseq system call.
If unsure, say N.
init/Kconfig: fix EXPERT menu list The EXPERT menu list was recently broken by the insertion of a kconfig symbol (EMBEDDED) at the beginning of the EXPERT list of kconfig items. Broken by: commit 6a108a14fa356ef607be308b68337939e56ea94e Author: David Rientjes <rientjes@google.com> Date: Thu Jan 20 14:44:16 2011 -0800 kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT Restore the EXPERT menu list -- don't inject a symbol (EMBEDDED) that does not depend on EXPERT into the list. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Peter Foley <pefoley2@verizon.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-27 03:33:21 +08:00
config EMBEDDED
bool "Embedded system"
kconfig: make allnoconfig disable options behind EMBEDDED and EXPERT "make allnoconfig" exists to ease testing of minimal configurations. Documentation/SubmitChecklist includes a note to test with allnoconfig. This helps catch missing dependencies on common-but-not-required functionality, which might otherwise go unnoticed. However, allnoconfig still leaves many symbols enabled, because they're hidden behind CONFIG_EMBEDDED or CONFIG_EXPERT. For instance, allnoconfig still has CONFIG_PRINTK and CONFIG_BLOCK enabled, so drivers don't typically get build-tested with those disabled. To address this, introduce a new Kconfig option "allnoconfig_y", used on symbols which only exist to hide other symbols. Set it on CONFIG_EMBEDDED (which then selects CONFIG_EXPERT). allnoconfig will then disable all the symbols hidden behind those. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 06:39:09 +08:00
option allnoconfig_y
init/Kconfig: fix EXPERT menu list The EXPERT menu list was recently broken by the insertion of a kconfig symbol (EMBEDDED) at the beginning of the EXPERT list of kconfig items. Broken by: commit 6a108a14fa356ef607be308b68337939e56ea94e Author: David Rientjes <rientjes@google.com> Date: Thu Jan 20 14:44:16 2011 -0800 kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT Restore the EXPERT menu list -- don't inject a symbol (EMBEDDED) that does not depend on EXPERT into the list. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Peter Foley <pefoley2@verizon.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-27 03:33:21 +08:00
select EXPERT
help
This option should be enabled if compiling the kernel for
an embedded system so certain expert options are available
for configuration.
perf: Do the big rename: Performance Counters -> Performance Events Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\<event\>/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:02:48 +08:00
config HAVE_PERF_EVENTS
performance counters: core code Implement the core kernel bits of Performance Counters subsystem. The Linux Performance Counter subsystem provides an abstraction of performance counter hardware capabilities. It provides per task and per CPU counters, and it provides event capabilities on top of those. Performance counters are accessed via special file descriptors. There's one file descriptor per virtual counter used. The special file descriptor is opened via the perf_counter_open() system call: int perf_counter_open(u32 hw_event_type, u32 hw_event_period, u32 record_type, pid_t pid, int cpu); The syscall returns the new fd. The fd can be used via the normal VFS system calls: read() can be used to read the counter, fcntl() can be used to set the blocking mode, etc. Multiple counters can be kept open at a time, and the counters can be poll()ed. See more details in Documentation/perf-counters.txt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-05 03:12:29 +08:00
bool
perf_counter: Start documenting HAVE_PERF_COUNTERS requirements Help out arch porters who want to support perf counters by listing some basic requirements. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1244827063-24046-1-git-send-email-vapier@gentoo.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-13 01:17:43 +08:00
help
See tools/perf/design.txt for details.
performance counters: core code Implement the core kernel bits of Performance Counters subsystem. The Linux Performance Counter subsystem provides an abstraction of performance counter hardware capabilities. It provides per task and per CPU counters, and it provides event capabilities on top of those. Performance counters are accessed via special file descriptors. There's one file descriptor per virtual counter used. The special file descriptor is opened via the perf_counter_open() system call: int perf_counter_open(u32 hw_event_type, u32 hw_event_period, u32 record_type, pid_t pid, int cpu); The syscall returns the new fd. The fd can be used via the normal VFS system calls: read() can be used to read the counter, fcntl() can be used to set the blocking mode, etc. Multiple counters can be kept open at a time, and the counters can be poll()ed. See more details in Documentation/perf-counters.txt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-05 03:12:29 +08:00
perf_event: Provide vmalloc() based mmap() backing Some architectures such as Sparc, ARM and MIPS (basically everything with flush_dcache_page()) need to deal with dcache aliases by carefully placing pages in both kernel and user maps. These architectures typically have to use vmalloc_user() for this. However, on other architectures, vmalloc() is not needed and has the downsides of being more restricted and slower than regular allocations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: David Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1254830228.21044.272.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 22:08:49 +08:00
config PERF_USE_VMALLOC
bool
help
See tools/perf/design.txt for details
pc104: Introduce the PC104 Kconfig option PC/104 form factor devices serve a specific niche of embedded system users; most Linux users will not have PC/104 form factor devices. This patch introduces the PC104 Kconfig option, which should be used to filter PC/104 specific device drivers and options, so that only those users interested in PC/104 related options are exposed to them. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11 02:50:54 +08:00
config PC104
pc104: Add EXPERT dependency for PC104 Kconfig option PC/104 device driver Kconfig options previously had an implicit EXPERT dependency by way of an explicit ISA_BUS_API dependency. Now that these driver Kconfig options select ISA_BUS_API rather than depend on it, the PC104 Kconfig option should have an explicit EXPERT dependency. The PC/104 form factor and bus architecture are common in embedded and specialized systems, but uncommon in typical desktop setups. For this reason, it is best to mask these devices and configurations via the EXPERT Kconfig option because the majority of users will never need to concern themselves with PC/104. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-12-30 04:14:59 +08:00
bool "PC/104 support" if EXPERT
pc104: Introduce the PC104 Kconfig option PC/104 form factor devices serve a specific niche of embedded system users; most Linux users will not have PC/104 form factor devices. This patch introduces the PC104 Kconfig option, which should be used to filter PC/104 specific device drivers and options, so that only those users interested in PC/104 related options are exposed to them. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11 02:50:54 +08:00
help
Expose PC/104 form factor device drivers and options available for
selection and configuration. Enable this option if your target
machine has a PC/104 bus.
perf: Tidy up after the big rename - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's - provide courtesy copy of old perf_counter.h, for user-space projects - small indentation fixups - fix up MAINTAINERS - fix small x86 printout fallout - fix up small PowerPC comment fallout (use 'counter' as in register) Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:20:38 +08:00
menu "Kernel Performance Events And Counters"
performance counters: core code Implement the core kernel bits of Performance Counters subsystem. The Linux Performance Counter subsystem provides an abstraction of performance counter hardware capabilities. It provides per task and per CPU counters, and it provides event capabilities on top of those. Performance counters are accessed via special file descriptors. There's one file descriptor per virtual counter used. The special file descriptor is opened via the perf_counter_open() system call: int perf_counter_open(u32 hw_event_type, u32 hw_event_period, u32 record_type, pid_t pid, int cpu); The syscall returns the new fd. The fd can be used via the normal VFS system calls: read() can be used to read the counter, fcntl() can be used to set the blocking mode, etc. Multiple counters can be kept open at a time, and the counters can be poll()ed. See more details in Documentation/perf-counters.txt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-05 03:12:29 +08:00
perf: Do the big rename: Performance Counters -> Performance Events Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\<event\>/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:02:48 +08:00
config PERF_EVENTS
perf: Tidy up after the big rename - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's - provide courtesy copy of old perf_counter.h, for user-space projects - small indentation fixups - fix up MAINTAINERS - fix small x86 printout fallout - fix up small PowerPC comment fallout (use 'counter' as in register) Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:20:38 +08:00
bool "Kernel performance events and counters"
perf: Remove PERF_COUNTERS config option Renaming remaining PERF_COUNTERS options into PERF_EVENTS. Think we can get rid of PERF_COUNTERS now. Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1333643084-26776-5-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-04-06 00:24:44 +08:00
default y if PROFILING
perf: Do the big rename: Performance Counters -> Performance Events Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\<event\>/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:02:48 +08:00
depends on HAVE_PERF_EVENTS
irq_work: Add generic hardirq context callbacks Provide a mechanism that allows running code in IRQ context. It is most useful for NMI code that needs to interact with the rest of the system -- like wakeup a task to drain buffers. Perf currently has such a mechanism, so extract that and provide it as a generic feature, independent of perf so that others may also benefit. The IRQ context callback is generated through self-IPIs where possible, or on architectures like powerpc the decrementer (the built-in timer facility) is set to generate an interrupt immediately. Architectures that don't have anything like this get to do with a callback from the timer tick. These architectures can call irq_work_run() at the tail of any IRQ handlers that might enqueue such work (like the perf IRQ handler) to avoid undue latencies in processing the work. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [ various fixes ] Signed-off-by: Huang Ying <ying.huang@intel.com> LKML-Reference: <1287036094.7768.291.camel@yhuang-dev> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-14 14:01:34 +08:00
select IRQ_WORK
rcu: Make SRCU optional by using CONFIG_SRCU SRCU is not necessary to be compiled by default in all cases. For tinification efforts not compiling SRCU unless necessary is desirable. The current patch tries to make compiling SRCU optional by introducing a new Kconfig option CONFIG_SRCU which is selected when any of the components making use of SRCU are selected. If we do not select CONFIG_SRCU, srcu.o will not be compiled at all. text data bss dec hex filename 2007 0 0 2007 7d7 kernel/rcu/srcu.o Size of arch/powerpc/boot/zImage changes from text data bss dec hex filename 831552 64180 23944 919676 e087c arch/powerpc/boot/zImage : before 829504 64180 23952 917636 e0084 arch/powerpc/boot/zImage : after so the savings are about ~2000 bytes. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com> CC: Josh Triplett <josh@joshtriplett.org> CC: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]
2014-12-06 00:24:45 +08:00
select SRCU
performance counters: core code Implement the core kernel bits of Performance Counters subsystem. The Linux Performance Counter subsystem provides an abstraction of performance counter hardware capabilities. It provides per task and per CPU counters, and it provides event capabilities on top of those. Performance counters are accessed via special file descriptors. There's one file descriptor per virtual counter used. The special file descriptor is opened via the perf_counter_open() system call: int perf_counter_open(u32 hw_event_type, u32 hw_event_period, u32 record_type, pid_t pid, int cpu); The syscall returns the new fd. The fd can be used via the normal VFS system calls: read() can be used to read the counter, fcntl() can be used to set the blocking mode, etc. Multiple counters can be kept open at a time, and the counters can be poll()ed. See more details in Documentation/perf-counters.txt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-05 03:12:29 +08:00
help
perf: Tidy up after the big rename - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's - provide courtesy copy of old perf_counter.h, for user-space projects - small indentation fixups - fix up MAINTAINERS - fix small x86 printout fallout - fix up small PowerPC comment fallout (use 'counter' as in register) Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:20:38 +08:00
Enable kernel support for various performance events provided
by software and hardware.
performance counters: core code Implement the core kernel bits of Performance Counters subsystem. The Linux Performance Counter subsystem provides an abstraction of performance counter hardware capabilities. It provides per task and per CPU counters, and it provides event capabilities on top of those. Performance counters are accessed via special file descriptors. There's one file descriptor per virtual counter used. The special file descriptor is opened via the perf_counter_open() system call: int perf_counter_open(u32 hw_event_type, u32 hw_event_period, u32 record_type, pid_t pid, int cpu); The syscall returns the new fd. The fd can be used via the normal VFS system calls: read() can be used to read the counter, fcntl() can be used to set the blocking mode, etc. Multiple counters can be kept open at a time, and the counters can be poll()ed. See more details in Documentation/perf-counters.txt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-05 03:12:29 +08:00
perf_events: Fix some typo in the perf events config description Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Cc: trivial@kernel.org LKML-Reference: <1256938346-8230-1-git-send-email-cascardo@holoscopio.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-31 05:32:25 +08:00
Software events are supported either built-in or via the
perf: Tidy up after the big rename - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's - provide courtesy copy of old perf_counter.h, for user-space projects - small indentation fixups - fix up MAINTAINERS - fix small x86 printout fallout - fix up small PowerPC comment fallout (use 'counter' as in register) Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:20:38 +08:00
use of generic tracepoints.
performance counters: core code Implement the core kernel bits of Performance Counters subsystem. The Linux Performance Counter subsystem provides an abstraction of performance counter hardware capabilities. It provides per task and per CPU counters, and it provides event capabilities on top of those. Performance counters are accessed via special file descriptors. There's one file descriptor per virtual counter used. The special file descriptor is opened via the perf_counter_open() system call: int perf_counter_open(u32 hw_event_type, u32 hw_event_period, u32 record_type, pid_t pid, int cpu); The syscall returns the new fd. The fd can be used via the normal VFS system calls: read() can be used to read the counter, fcntl() can be used to set the blocking mode, etc. Multiple counters can be kept open at a time, and the counters can be poll()ed. See more details in Documentation/perf-counters.txt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-05 03:12:29 +08:00
perf: Tidy up after the big rename - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's - provide courtesy copy of old perf_counter.h, for user-space projects - small indentation fixups - fix up MAINTAINERS - fix small x86 printout fallout - fix up small PowerPC comment fallout (use 'counter' as in register) Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:20:38 +08:00
Most modern CPUs support performance events via performance
counter registers. These registers count the number of certain
performance counters: core code Implement the core kernel bits of Performance Counters subsystem. The Linux Performance Counter subsystem provides an abstraction of performance counter hardware capabilities. It provides per task and per CPU counters, and it provides event capabilities on top of those. Performance counters are accessed via special file descriptors. There's one file descriptor per virtual counter used. The special file descriptor is opened via the perf_counter_open() system call: int perf_counter_open(u32 hw_event_type, u32 hw_event_period, u32 record_type, pid_t pid, int cpu); The syscall returns the new fd. The fd can be used via the normal VFS system calls: read() can be used to read the counter, fcntl() can be used to set the blocking mode, etc. Multiple counters can be kept open at a time, and the counters can be poll()ed. See more details in Documentation/perf-counters.txt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-05 03:12:29 +08:00
types of hw events: such as instructions executed, cachemisses
suffered, or branches mis-predicted - without slowing down the
kernel or applications. These registers can also trigger interrupts
when a threshold number of events have passed - and can thus be
used to profile the code that runs on that CPU.
perf: Tidy up after the big rename - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's - provide courtesy copy of old perf_counter.h, for user-space projects - small indentation fixups - fix up MAINTAINERS - fix small x86 printout fallout - fix up small PowerPC comment fallout (use 'counter' as in register) Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:20:38 +08:00
The Linux Performance Event subsystem provides an abstraction of
perf_events: Fix some typo in the perf events config description Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Cc: trivial@kernel.org LKML-Reference: <1256938346-8230-1-git-send-email-cascardo@holoscopio.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-31 05:32:25 +08:00
these software and hardware event capabilities, available via a
perf: Tidy up after the big rename - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's - provide courtesy copy of old perf_counter.h, for user-space projects - small indentation fixups - fix up MAINTAINERS - fix small x86 printout fallout - fix up small PowerPC comment fallout (use 'counter' as in register) Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 18:20:38 +08:00
system call and used by the "perf" utility in tools/perf/. It
performance counters: core code Implement the core kernel bits of Performance Counters subsystem. The Linux Performance Counter subsystem provides an abstraction of performance counter hardware capabilities. It provides per task and per CPU counters, and it provides event capabilities on top of those. Performance counters are accessed via special file descriptors. There's one file descriptor per virtual counter used. The special file descriptor is opened via the perf_counter_open() system call: int perf_counter_open(u32 hw_event_type, u32 hw_event_period, u32 record_type, pid_t pid, int cpu); The syscall returns the new fd. The fd can be used via the normal VFS system calls: read() can be used to read the counter, fcntl() can be used to set the blocking mode, etc. Multiple counters can be kept open at a time, and the counters can be poll()ed. See more details in Documentation/perf-counters.txt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-05 03:12:29 +08:00
provides per task and per CPU counters, and it provides event
capabilities on top of those.
Say Y if unsure.
perf_event: Provide vmalloc() based mmap() backing Some architectures such as Sparc, ARM and MIPS (basically everything with flush_dcache_page()) need to deal with dcache aliases by carefully placing pages in both kernel and user maps. These architectures typically have to use vmalloc_user() for this. However, on other architectures, vmalloc() is not needed and has the downsides of being more restricted and slower than regular allocations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: David Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1254830228.21044.272.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 22:08:49 +08:00
config DEBUG_PERF_USE_VMALLOC
default n
bool "Debug: use vmalloc to back perf mmap() buffers"
perf_event: Don't allow vmalloc() backed perf on powerpc On powerpc the perf event interrupt is not masked when interrupts are disabled, allowing it to function as an NMI. This causes problems if perf is using vmalloc. If we take a page fault on the vmalloc region the fault handler will fail the page fault because it detects we are coming in from an NMI (see do_hash_page()). We don't actually need or want vmalloc backed perf so just disable it on powerpc. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <linuxppc-dev@ozlabs.org> Cc: Andrew Morton <akpm@osdl.org> Cc: Anton Blanchard <anton@samba.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@ghostprotocols.net Cc: sukadev@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1430720799-18426-1-git-send-email-mpe@ellerman.id.au Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-04 14:26:39 +08:00
depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
perf_event: Provide vmalloc() based mmap() backing Some architectures such as Sparc, ARM and MIPS (basically everything with flush_dcache_page()) need to deal with dcache aliases by carefully placing pages in both kernel and user maps. These architectures typically have to use vmalloc_user() for this. However, on other architectures, vmalloc() is not needed and has the downsides of being more restricted and slower than regular allocations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: David Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1254830228.21044.272.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 22:08:49 +08:00
select PERF_USE_VMALLOC
help
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
Use vmalloc memory to back perf mmap() buffers.
perf_event: Provide vmalloc() based mmap() backing Some architectures such as Sparc, ARM and MIPS (basically everything with flush_dcache_page()) need to deal with dcache aliases by carefully placing pages in both kernel and user maps. These architectures typically have to use vmalloc_user() for this. However, on other architectures, vmalloc() is not needed and has the downsides of being more restricted and slower than regular allocations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: David Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1254830228.21044.272.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 22:08:49 +08:00
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
Mostly useful for debugging the vmalloc code on platforms
that don't require it.
perf_event: Provide vmalloc() based mmap() backing Some architectures such as Sparc, ARM and MIPS (basically everything with flush_dcache_page()) need to deal with dcache aliases by carefully placing pages in both kernel and user maps. These architectures typically have to use vmalloc_user() for this. However, on other architectures, vmalloc() is not needed and has the downsides of being more restricted and slower than regular allocations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: David Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1254830228.21044.272.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 22:08:49 +08:00
init/Kconfig: fix indentation Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ / /' -i */Kconfig Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-05 08:52:28 +08:00
Say N if unsure.
perf_event: Provide vmalloc() based mmap() backing Some architectures such as Sparc, ARM and MIPS (basically everything with flush_dcache_page()) need to deal with dcache aliases by carefully placing pages in both kernel and user maps. These architectures typically have to use vmalloc_user() for this. However, on other architectures, vmalloc() is not needed and has the downsides of being more restricted and slower than regular allocations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: David Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1254830228.21044.272.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 22:08:49 +08:00
performance counters: core code Implement the core kernel bits of Performance Counters subsystem. The Linux Performance Counter subsystem provides an abstraction of performance counter hardware capabilities. It provides per task and per CPU counters, and it provides event capabilities on top of those. Performance counters are accessed via special file descriptors. There's one file descriptor per virtual counter used. The special file descriptor is opened via the perf_counter_open() system call: int perf_counter_open(u32 hw_event_type, u32 hw_event_period, u32 record_type, pid_t pid, int cpu); The syscall returns the new fd. The fd can be used via the normal VFS system calls: read() can be used to read the counter, fcntl() can be used to set the blocking mode, etc. Multiple counters can be kept open at a time, and the counters can be poll()ed. See more details in Documentation/perf-counters.txt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-05 03:12:29 +08:00
endmenu
[PATCH] Light weight event counters The remaining counters in page_state after the zoned VM counter patches have been applied are all just for show in /proc/vmstat. They have no essential function for the VM. We use a simple increment of per cpu variables. In order to avoid the most severe races we disable preempt. Preempt does not prevent the race between an increment and an interrupt handler incrementing the same statistics counter. However, that race is exceedingly rare, we may only loose one increment or so and there is no requirement (at least not in kernel) that the vm event counters have to be accurate. In the non preempt case this results in a simple increment for each counter. For many architectures this will be reduced by the compiler to a single instruction. This single instruction is atomic for i386 and x86_64. And therefore even the rare race condition in an interrupt is avoided for both architectures in most cases. The patchset also adds an off switch for embedded systems that allows a building of linux kernels without these counters. The implementation of these counters is through inline code that hopefully results in only a single instruction increment instruction being emitted (i386, x86_64) or in the increment being hidden though instruction concurrency (EPIC architectures such as ia64 can get that done). Benefits: - VM event counter operations usually reduce to a single inline instruction on i386 and x86_64. - No interrupt disable, only preempt disable for the preempt case. Preempt disable can also be avoided by moving the counter into a spinlock. - Handling is similar to zoned VM counters. - Simple and easily extendable. - Can be omitted to reduce memory use for embedded use. References: RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=113512330605497&w=2 RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=114988082814934&w=2 local_t http://marc.theaimsgroup.com/?l=linux-kernel&m=114991748606690&w=2 V2 http://marc.theaimsgroup.com/?t=115014808400007&r=1&w=2 V3 http://marc.theaimsgroup.com/?l=linux-kernel&m=115024767022346&w=2 V4 http://marc.theaimsgroup.com/?l=linux-kernel&m=115047968808926&w=2 Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30 16:55:45 +08:00
config VM_EVENT_COUNTERS
default y
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable VM event counters for /proc/vmstat" if EXPERT
[PATCH] Light weight event counters The remaining counters in page_state after the zoned VM counter patches have been applied are all just for show in /proc/vmstat. They have no essential function for the VM. We use a simple increment of per cpu variables. In order to avoid the most severe races we disable preempt. Preempt does not prevent the race between an increment and an interrupt handler incrementing the same statistics counter. However, that race is exceedingly rare, we may only loose one increment or so and there is no requirement (at least not in kernel) that the vm event counters have to be accurate. In the non preempt case this results in a simple increment for each counter. For many architectures this will be reduced by the compiler to a single instruction. This single instruction is atomic for i386 and x86_64. And therefore even the rare race condition in an interrupt is avoided for both architectures in most cases. The patchset also adds an off switch for embedded systems that allows a building of linux kernels without these counters. The implementation of these counters is through inline code that hopefully results in only a single instruction increment instruction being emitted (i386, x86_64) or in the increment being hidden though instruction concurrency (EPIC architectures such as ia64 can get that done). Benefits: - VM event counter operations usually reduce to a single inline instruction on i386 and x86_64. - No interrupt disable, only preempt disable for the preempt case. Preempt disable can also be avoided by moving the counter into a spinlock. - Handling is similar to zoned VM counters. - Simple and easily extendable. - Can be omitted to reduce memory use for embedded use. References: RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=113512330605497&w=2 RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=114988082814934&w=2 local_t http://marc.theaimsgroup.com/?l=linux-kernel&m=114991748606690&w=2 V2 http://marc.theaimsgroup.com/?t=115014808400007&r=1&w=2 V3 http://marc.theaimsgroup.com/?l=linux-kernel&m=115024767022346&w=2 V4 http://marc.theaimsgroup.com/?l=linux-kernel&m=115047968808926&w=2 Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30 16:55:45 +08:00
help
[PATCH] CONFIG_VM_EVENT_COUNTER comment decrustify The VM event counters, enabled by CONFIG_VM_EVENT_COUNTERS, which provides VM event counters in /proc/vmstat, has become more essential to non-EMBEDDED kernel configurations than they were in the past. Comments in the code and the Kconfig configuration explanation were stale, downplaying their role excessively. Refresh those comments to correctly reflect the current role of VM event counters. Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-22 17:06:10 +08:00
VM event counters are needed for event counts to be shown.
This option allows the disabling of the VM event counters
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
on EXPERT systems. /proc/vmstat will only show page counts
[PATCH] CONFIG_VM_EVENT_COUNTER comment decrustify The VM event counters, enabled by CONFIG_VM_EVENT_COUNTERS, which provides VM event counters in /proc/vmstat, has become more essential to non-EMBEDDED kernel configurations than they were in the past. Comments in the code and the Kconfig configuration explanation were stale, downplaying their role excessively. Refresh those comments to correctly reflect the current role of VM event counters. Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-22 17:06:10 +08:00
if VM event counters are disabled.
[PATCH] Light weight event counters The remaining counters in page_state after the zoned VM counter patches have been applied are all just for show in /proc/vmstat. They have no essential function for the VM. We use a simple increment of per cpu variables. In order to avoid the most severe races we disable preempt. Preempt does not prevent the race between an increment and an interrupt handler incrementing the same statistics counter. However, that race is exceedingly rare, we may only loose one increment or so and there is no requirement (at least not in kernel) that the vm event counters have to be accurate. In the non preempt case this results in a simple increment for each counter. For many architectures this will be reduced by the compiler to a single instruction. This single instruction is atomic for i386 and x86_64. And therefore even the rare race condition in an interrupt is avoided for both architectures in most cases. The patchset also adds an off switch for embedded systems that allows a building of linux kernels without these counters. The implementation of these counters is through inline code that hopefully results in only a single instruction increment instruction being emitted (i386, x86_64) or in the increment being hidden though instruction concurrency (EPIC architectures such as ia64 can get that done). Benefits: - VM event counter operations usually reduce to a single inline instruction on i386 and x86_64. - No interrupt disable, only preempt disable for the preempt case. Preempt disable can also be avoided by moving the counter into a spinlock. - Handling is similar to zoned VM counters. - Simple and easily extendable. - Can be omitted to reduce memory use for embedded use. References: RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=113512330605497&w=2 RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=114988082814934&w=2 local_t http://marc.theaimsgroup.com/?l=linux-kernel&m=114991748606690&w=2 V2 http://marc.theaimsgroup.com/?t=115014808400007&r=1&w=2 V3 http://marc.theaimsgroup.com/?l=linux-kernel&m=115024767022346&w=2 V4 http://marc.theaimsgroup.com/?l=linux-kernel&m=115047968808926&w=2 Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30 16:55:45 +08:00
SLUB: add CONFIG_SLUB_DEBUG CONFIG_SLUB_DEBUG can be used to switch off the debugging and sysfs components of SLUB. Thus SLUB will be able to replace SLOB. SLUB can arrange objects in a denser way than SLOB and the code size should be minimal without debugging and sysfs support. Note that CONFIG_SLUB_DEBUG is materially different from CONFIG_SLAB_DEBUG. CONFIG_SLAB_DEBUG is used to enable slab debugging in SLAB. SLUB enables debugging via a boot parameter. SLUB debug code should always be present. CONFIG_SLUB_DEBUG can be modified in the embedded config section. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 17:32:44 +08:00
config SLUB_DEBUG
default y
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
bool "Enable SLUB debugging support" if EXPERT
slub: #ifdef simplification If we make SLUB_DEBUG depend on SYSFS then we can simplify some #ifdefs and avoid others. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-04-30 07:16:06 +08:00
depends on SLUB && SYSFS
SLUB: add CONFIG_SLUB_DEBUG CONFIG_SLUB_DEBUG can be used to switch off the debugging and sysfs components of SLUB. Thus SLUB will be able to replace SLOB. SLUB can arrange objects in a denser way than SLOB and the code size should be minimal without debugging and sysfs support. Note that CONFIG_SLUB_DEBUG is materially different from CONFIG_SLAB_DEBUG. CONFIG_SLAB_DEBUG is used to enable slab debugging in SLAB. SLUB enables debugging via a boot parameter. SLUB debug code should always be present. CONFIG_SLUB_DEBUG can be modified in the embedded config section. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 17:32:44 +08:00
help
SLUB has extensive debug support features. Disabling these can
result in significant savings in code size. This also disables
SLUB sysfs support. /sys/slab will not exist and there will be
no support for cache validation etc.
slub: make sysfs directories for memcg sub-caches optional SLUB creates a per-cache directory under /sys/kernel/slab which hosts a bunch of debug files. Usually, there aren't that many caches on a system and this doesn't really matter; however, if memcg is in use, each cache can have per-cgroup sub-caches. SLUB creates the same directories for these sub-caches under /sys/kernel/slab/$CACHE/cgroup. Unfortunately, because there can be a lot of cgroups, active or draining, the product of the numbers of caches, cgroups and files in each directory can reach a very high number - hundreds of thousands is commonplace. Millions and beyond aren't difficult to reach either. What's under /sys/kernel/slab is primarily for debugging and the information and control on the a root cache already cover its sub-caches. While having a separate directory for each sub-cache can be helpful for development, it doesn't make much sense to pay this amount of overhead by default. This patch introduces a boot parameter slub_memcg_sysfs which determines whether to create sysfs directories for per-memcg sub-caches. It also adds CONFIG_SLUB_MEMCG_SYSFS_ON which determines the boot parameter's default value and defaults to 0. [akpm@linux-foundation.org: kset_unregister(NULL) is legal] Link: http://lkml.kernel.org/r/20170204145203.GB26958@mtj.duckdns.org Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-23 07:41:39 +08:00
config SLUB_MEMCG_SYSFS_ON
default n
bool "Enable memcg SLUB sysfs support by default" if EXPERT
depends on SLUB && SYSFS && MEMCG
help
SLUB creates a directory under /sys/kernel/slab for each
allocation cache to host info and debug files. If memory
cgroup is enabled, each cache can have per memory cgroup
caches. SLUB can create the same sysfs directories for these
caches under /sys/kernel/slab/CACHE/cgroup but it can lead
to a very high number of debug files being created. This is
controlled by slub_memcg_sysfs boot parameter and this
config option determines the parameter's default value.
menu: fix embedded menu snafu The COMPAT_BRK kconfig symbol does not depend on EMBEDDED, but it is in the midst of the EMBEDDED menu symbols, so it mucks up the EMBEDDED menu. Fix by moving it to just after all of the EMBEDDED menu symbols. Also, ANON_INODES has a similar problem, so move it to just above the EMBEDDED menu items since it is used in the EMBEDDED menu. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-11 03:55:46 +08:00
config COMPAT_BRK
bool "Disable heap randomization"
default y
help
Randomizing heap placement makes heap exploits harder, but it
also breaks ancient binaries (including anything libc5 based).
This option changes the bootup default to heap randomization
trivial: fix typos/grammar errors in Kconfig texts Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-01-26 18:12:25 +08:00
disabled, and can be overridden at runtime by setting
menu: fix embedded menu snafu The COMPAT_BRK kconfig symbol does not depend on EMBEDDED, but it is in the midst of the EMBEDDED menu symbols, so it mucks up the EMBEDDED menu. Fix by moving it to just after all of the EMBEDDED menu symbols. Also, ANON_INODES has a similar problem, so move it to just above the EMBEDDED menu items since it is used in the EMBEDDED menu. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-11 03:55:46 +08:00
/proc/sys/kernel/randomize_va_space to 2.
On non-ancient distros (post-2000 ones) N is usually a safe choice.
SLUB core This is a new slab allocator which was motivated by the complexity of the existing code in mm/slab.c. It attempts to address a variety of concerns with the existing implementation. A. Management of object queues A particular concern was the complex management of the numerous object queues in SLAB. SLUB has no such queues. Instead we dedicate a slab for each allocating CPU and use objects from a slab directly instead of queueing them up. B. Storage overhead of object queues SLAB Object queues exist per node, per CPU. The alien cache queue even has a queue array that contain a queue for each processor on each node. For very large systems the number of queues and the number of objects that may be caught in those queues grows exponentially. On our systems with 1k nodes / processors we have several gigabytes just tied up for storing references to objects for those queues This does not include the objects that could be on those queues. One fears that the whole memory of the machine could one day be consumed by those queues. C. SLAB meta data overhead SLAB has overhead at the beginning of each slab. This means that data cannot be naturally aligned at the beginning of a slab block. SLUB keeps all meta data in the corresponding page_struct. Objects can be naturally aligned in the slab. F.e. a 128 byte object will be aligned at 128 byte boundaries and can fit tightly into a 4k page with no bytes left over. SLAB cannot do this. D. SLAB has a complex cache reaper SLUB does not need a cache reaper for UP systems. On SMP systems the per CPU slab may be pushed back into partial list but that operation is simple and does not require an iteration over a list of objects. SLAB expires per CPU, shared and alien object queues during cache reaping which may cause strange hold offs. E. SLAB has complex NUMA policy layer support SLUB pushes NUMA policy handling into the page allocator. This means that allocation is coarser (SLUB does interleave on a page level) but that situation was also present before 2.6.13. SLABs application of policies to individual slab objects allocated in SLAB is certainly a performance concern due to the frequent references to memory policies which may lead a sequence of objects to come from one node after another. SLUB will get a slab full of objects from one node and then will switch to the next. F. Reduction of the size of partial slab lists SLAB has per node partial lists. This means that over time a large number of partial slabs may accumulate on those lists. These can only be reused if allocator occur on specific nodes. SLUB has a global pool of partial slabs and will consume slabs from that pool to decrease fragmentation. G. Tunables SLAB has sophisticated tuning abilities for each slab cache. One can manipulate the queue sizes in detail. However, filling the queues still requires the uses of the spin lock to check out slabs. SLUB has a global parameter (min_slab_order) for tuning. Increasing the minimum slab order can decrease the locking overhead. The bigger the slab order the less motions of pages between per CPU and partial lists occur and the better SLUB will be scaling. G. Slab merging We often have slab caches with similar parameters. SLUB detects those on boot up and merges them into the corresponding general caches. This leads to more effective memory use. About 50% of all caches can be eliminated through slab merging. This will also decrease slab fragmentation because partial allocated slabs can be filled up again. Slab merging can be switched off by specifying slub_nomerge on boot up. Note that merging can expose heretofore unknown bugs in the kernel because corrupted objects may now be placed differently and corrupt differing neighboring objects. Enable sanity checks to find those. H. Diagnostics The current slab diagnostics are difficult to use and require a recompilation of the kernel. SLUB contains debugging code that is always available (but is kept out of the hot code paths). SLUB diagnostics can be enabled via the "slab_debug" option. Parameters can be specified to select a single or a group of slab caches for diagnostics. This means that the system is running with the usual performance and it is much more likely that race conditions can be reproduced. I. Resiliency If basic sanity checks are on then SLUB is capable of detecting common error conditions and recover as best as possible to allow the system to continue. J. Tracing Tracing can be enabled via the slab_debug=T,<slabcache> option during boot. SLUB will then protocol all actions on that slabcache and dump the object contents on free. K. On demand DMA cache creation. Generally DMA caches are not needed. If a kmalloc is used with __GFP_DMA then just create this single slabcache that is needed. For systems that have no ZONE_DMA requirement the support is completely eliminated. L. Performance increase Some benchmarks have shown speed improvements on kernbench in the range of 5-10%. The locking overhead of slub is based on the underlying base allocation size. If we can reliably allocate larger order pages then it is possible to increase slub performance much further. The anti-fragmentation patches may enable further performance increases. Tested on: i386 UP + SMP, x86_64 UP + SMP + NUMA emulation, IA64 NUMA + Simulator SLUB Boot options slub_nomerge Disable merging of slabs slub_min_order=x Require a minimum order for slab caches. This increases the managed chunk size and therefore reduces meta data and locking overhead. slub_min_objects=x Mininum objects per slab. Default is 8. slub_max_order=x Avoid generating slabs larger than order specified. slub_debug Enable all diagnostics for all caches slub_debug=<options> Enable selective options for all caches slub_debug=<o>,<cache> Enable selective options for a certain set of caches Available Debug options F Double Free checking, sanity and resiliency R Red zoning P Object / padding poisoning U Track last free / alloc T Trace all allocs / frees (only use for individual slabs). To use SLUB: Apply this patch and then select SLUB as the default slab allocator. [hugh@veritas.com: fix an oops-causing locking error] [akpm@linux-foundation.org: various stupid cleanups and small fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 05:49:36 +08:00
choice
prompt "Choose SLAB allocator"
Make SLUB the default allocator There are some reports that 2.6.22 has SLUB as the default. Not true! This will make SLUB the default for 2.6.23. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 19:03:32 +08:00
default SLUB
SLUB core This is a new slab allocator which was motivated by the complexity of the existing code in mm/slab.c. It attempts to address a variety of concerns with the existing implementation. A. Management of object queues A particular concern was the complex management of the numerous object queues in SLAB. SLUB has no such queues. Instead we dedicate a slab for each allocating CPU and use objects from a slab directly instead of queueing them up. B. Storage overhead of object queues SLAB Object queues exist per node, per CPU. The alien cache queue even has a queue array that contain a queue for each processor on each node. For very large systems the number of queues and the number of objects that may be caught in those queues grows exponentially. On our systems with 1k nodes / processors we have several gigabytes just tied up for storing references to objects for those queues This does not include the objects that could be on those queues. One fears that the whole memory of the machine could one day be consumed by those queues. C. SLAB meta data overhead SLAB has overhead at the beginning of each slab. This means that data cannot be naturally aligned at the beginning of a slab block. SLUB keeps all meta data in the corresponding page_struct. Objects can be naturally aligned in the slab. F.e. a 128 byte object will be aligned at 128 byte boundaries and can fit tightly into a 4k page with no bytes left over. SLAB cannot do this. D. SLAB has a complex cache reaper SLUB does not need a cache reaper for UP systems. On SMP systems the per CPU slab may be pushed back into partial list but that operation is simple and does not require an iteration over a list of objects. SLAB expires per CPU, shared and alien object queues during cache reaping which may cause strange hold offs. E. SLAB has complex NUMA policy layer support SLUB pushes NUMA policy handling into the page allocator. This means that allocation is coarser (SLUB does interleave on a page level) but that situation was also present before 2.6.13. SLABs application of policies to individual slab objects allocated in SLAB is certainly a performance concern due to the frequent references to memory policies which may lead a sequence of objects to come from one node after another. SLUB will get a slab full of objects from one node and then will switch to the next. F. Reduction of the size of partial slab lists SLAB has per node partial lists. This means that over time a large number of partial slabs may accumulate on those lists. These can only be reused if allocator occur on specific nodes. SLUB has a global pool of partial slabs and will consume slabs from that pool to decrease fragmentation. G. Tunables SLAB has sophisticated tuning abilities for each slab cache. One can manipulate the queue sizes in detail. However, filling the queues still requires the uses of the spin lock to check out slabs. SLUB has a global parameter (min_slab_order) for tuning. Increasing the minimum slab order can decrease the locking overhead. The bigger the slab order the less motions of pages between per CPU and partial lists occur and the better SLUB will be scaling. G. Slab merging We often have slab caches with similar parameters. SLUB detects those on boot up and merges them into the corresponding general caches. This leads to more effective memory use. About 50% of all caches can be eliminated through slab merging. This will also decrease slab fragmentation because partial allocated slabs can be filled up again. Slab merging can be switched off by specifying slub_nomerge on boot up. Note that merging can expose heretofore unknown bugs in the kernel because corrupted objects may now be placed differently and corrupt differing neighboring objects. Enable sanity checks to find those. H. Diagnostics The current slab diagnostics are difficult to use and require a recompilation of the kernel. SLUB contains debugging code that is always available (but is kept out of the hot code paths). SLUB diagnostics can be enabled via the "slab_debug" option. Parameters can be specified to select a single or a group of slab caches for diagnostics. This means that the system is running with the usual performance and it is much more likely that race conditions can be reproduced. I. Resiliency If basic sanity checks are on then SLUB is capable of detecting common error conditions and recover as best as possible to allow the system to continue. J. Tracing Tracing can be enabled via the slab_debug=T,<slabcache> option during boot. SLUB will then protocol all actions on that slabcache and dump the object contents on free. K. On demand DMA cache creation. Generally DMA caches are not needed. If a kmalloc is used with __GFP_DMA then just create this single slabcache that is needed. For systems that have no ZONE_DMA requirement the support is completely eliminated. L. Performance increase Some benchmarks have shown speed improvements on kernbench in the range of 5-10%. The locking overhead of slub is based on the underlying base allocation size. If we can reliably allocate larger order pages then it is possible to increase slub performance much further. The anti-fragmentation patches may enable further performance increases. Tested on: i386 UP + SMP, x86_64 UP + SMP + NUMA emulation, IA64 NUMA + Simulator SLUB Boot options slub_nomerge Disable merging of slabs slub_min_order=x Require a minimum order for slab caches. This increases the managed chunk size and therefore reduces meta data and locking overhead. slub_min_objects=x Mininum objects per slab. Default is 8. slub_max_order=x Avoid generating slabs larger than order specified. slub_debug Enable all diagnostics for all caches slub_debug=<options> Enable selective options for all caches slub_debug=<o>,<cache> Enable selective options for a certain set of caches Available Debug options F Double Free checking, sanity and resiliency R Red zoning P Object / padding poisoning U Track last free / alloc T Trace all allocs / frees (only use for individual slabs). To use SLUB: Apply this patch and then select SLUB as the default slab allocator. [hugh@veritas.com: fix an oops-causing locking error] [akpm@linux-foundation.org: various stupid cleanups and small fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 05:49:36 +08:00
help
This option allows to select a slab allocator.
config SLAB
bool "SLAB"
mm: SLAB hardened usercopy support Under CONFIG_HARDENED_USERCOPY, this adds object size checking to the SLAB allocator to catch any copies that may span objects. Based on code from PaX and grsecurity. Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
2016-06-24 06:20:59 +08:00
select HAVE_HARDENED_USERCOPY_ALLOCATOR
SLUB core This is a new slab allocator which was motivated by the complexity of the existing code in mm/slab.c. It attempts to address a variety of concerns with the existing implementation. A. Management of object queues A particular concern was the complex management of the numerous object queues in SLAB. SLUB has no such queues. Instead we dedicate a slab for each allocating CPU and use objects from a slab directly instead of queueing them up. B. Storage overhead of object queues SLAB Object queues exist per node, per CPU. The alien cache queue even has a queue array that contain a queue for each processor on each node. For very large systems the number of queues and the number of objects that may be caught in those queues grows exponentially. On our systems with 1k nodes / processors we have several gigabytes just tied up for storing references to objects for those queues This does not include the objects that could be on those queues. One fears that the whole memory of the machine could one day be consumed by those queues. C. SLAB meta data overhead SLAB has overhead at the beginning of each slab. This means that data cannot be naturally aligned at the beginning of a slab block. SLUB keeps all meta data in the corresponding page_struct. Objects can be naturally aligned in the slab. F.e. a 128 byte object will be aligned at 128 byte boundaries and can fit tightly into a 4k page with no bytes left over. SLAB cannot do this. D. SLAB has a complex cache reaper SLUB does not need a cache reaper for UP systems. On SMP systems the per CPU slab may be pushed back into partial list but that operation is simple and does not require an iteration over a list of objects. SLAB expires per CPU, shared and alien object queues during cache reaping which may cause strange hold offs. E. SLAB has complex NUMA policy layer support SLUB pushes NUMA policy handling into the page allocator. This means that allocation is coarser (SLUB does interleave on a page level) but that situation was also present before 2.6.13. SLABs application of policies to individual slab objects allocated in SLAB is certainly a performance concern due to the frequent references to memory policies which may lead a sequence of objects to come from one node after another. SLUB will get a slab full of objects from one node and then will switch to the next. F. Reduction of the size of partial slab lists SLAB has per node partial lists. This means that over time a large number of partial slabs may accumulate on those lists. These can only be reused if allocator occur on specific nodes. SLUB has a global pool of partial slabs and will consume slabs from that pool to decrease fragmentation. G. Tunables SLAB has sophisticated tuning abilities for each slab cache. One can manipulate the queue sizes in detail. However, filling the queues still requires the uses of the spin lock to check out slabs. SLUB has a global parameter (min_slab_order) for tuning. Increasing the minimum slab order can decrease the locking overhead. The bigger the slab order the less motions of pages between per CPU and partial lists occur and the better SLUB will be scaling. G. Slab merging We often have slab caches with similar parameters. SLUB detects those on boot up and merges them into the corresponding general caches. This leads to more effective memory use. About 50% of all caches can be eliminated through slab merging. This will also decrease slab fragmentation because partial allocated slabs can be filled up again. Slab merging can be switched off by specifying slub_nomerge on boot up. Note that merging can expose heretofore unknown bugs in the kernel because corrupted objects may now be placed differently and corrupt differing neighboring objects. Enable sanity checks to find those. H. Diagnostics The current slab diagnostics are difficult to use and require a recompilation of the kernel. SLUB contains debugging code that is always available (but is kept out of the hot code paths). SLUB diagnostics can be enabled via the "slab_debug" option. Parameters can be specified to select a single or a group of slab caches for diagnostics. This means that the system is running with the usual performance and it is much more likely that race conditions can be reproduced. I. Resiliency If basic sanity checks are on then SLUB is capable of detecting common error conditions and recover as best as possible to allow the system to continue. J. Tracing Tracing can be enabled via the slab_debug=T,<slabcache> option during boot. SLUB will then protocol all actions on that slabcache and dump the object contents on free. K. On demand DMA cache creation. Generally DMA caches are not needed. If a kmalloc is used with __GFP_DMA then just create this single slabcache that is needed. For systems that have no ZONE_DMA requirement the support is completely eliminated. L. Performance increase Some benchmarks have shown speed improvements on kernbench in the range of 5-10%. The locking overhead of slub is based on the underlying base allocation size. If we can reliably allocate larger order pages then it is possible to increase slub performance much further. The anti-fragmentation patches may enable further performance increases. Tested on: i386 UP + SMP, x86_64 UP + SMP + NUMA emulation, IA64 NUMA + Simulator SLUB Boot options slub_nomerge Disable merging of slabs slub_min_order=x Require a minimum order for slab caches. This increases the managed chunk size and therefore reduces meta data and locking overhead. slub_min_objects=x Mininum objects per slab. Default is 8. slub_max_order=x Avoid generating slabs larger than order specified. slub_debug Enable all diagnostics for all caches slub_debug=<options> Enable selective options for all caches slub_debug=<o>,<cache> Enable selective options for a certain set of caches Available Debug options F Double Free checking, sanity and resiliency R Red zoning P Object / padding poisoning U Track last free / alloc T Trace all allocs / frees (only use for individual slabs). To use SLUB: Apply this patch and then select SLUB as the default slab allocator. [hugh@veritas.com: fix an oops-causing locking error] [akpm@linux-foundation.org: various stupid cleanups and small fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 05:49:36 +08:00
help
The regular slab allocator that is established and known to work
Fix spellings of slab allocator section in init/Kconfig Fix some of the spelling issues. Fix sentences. Discourage SLOB use since SLUB can pack objects denser. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 17:32:47 +08:00
well in all environments. It organizes cache hot objects in
Kconfig: SLUB is the default slab allocator In 2007, a0acd820807680d2ccc4ef3448387fcdbf152c73 changed the default slab allocator to SLUB, but the SLAB help text still says SLAB is the default. This change fixes that. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-11-06 06:18:19 +08:00
per cpu and per node queues.
SLUB core This is a new slab allocator which was motivated by the complexity of the existing code in mm/slab.c. It attempts to address a variety of concerns with the existing implementation. A. Management of object queues A particular concern was the complex management of the numerous object queues in SLAB. SLUB has no such queues. Instead we dedicate a slab for each allocating CPU and use objects from a slab directly instead of queueing them up. B. Storage overhead of object queues SLAB Object queues exist per node, per CPU. The alien cache queue even has a queue array that contain a queue for each processor on each node. For very large systems the number of queues and the number of objects that may be caught in those queues grows exponentially. On our systems with 1k nodes / processors we have several gigabytes just tied up for storing references to objects for those queues This does not include the objects that could be on those queues. One fears that the whole memory of the machine could one day be consumed by those queues. C. SLAB meta data overhead SLAB has overhead at the beginning of each slab. This means that data cannot be naturally aligned at the beginning of a slab block. SLUB keeps all meta data in the corresponding page_struct. Objects can be naturally aligned in the slab. F.e. a 128 byte object will be aligned at 128 byte boundaries and can fit tightly into a 4k page with no bytes left over. SLAB cannot do this. D. SLAB has a complex cache reaper SLUB does not need a cache reaper for UP systems. On SMP systems the per CPU slab may be pushed back into partial list but that operation is simple and does not require an iteration over a list of objects. SLAB expires per CPU, shared and alien object queues during cache reaping which may cause strange hold offs. E. SLAB has complex NUMA policy layer support SLUB pushes NUMA policy handling into the page allocator. This means that allocation is coarser (SLUB does interleave on a page level) but that situation was also present before 2.6.13. SLABs application of policies to individual slab objects allocated in SLAB is certainly a performance concern due to the frequent references to memory policies which may lead a sequence of objects to come from one node after another. SLUB will get a slab full of objects from one node and then will switch to the next. F. Reduction of the size of partial slab lists SLAB has per node partial lists. This means that over time a large number of partial slabs may accumulate on those lists. These can only be reused if allocator occur on specific nodes. SLUB has a global pool of partial slabs and will consume slabs from that pool to decrease fragmentation. G. Tunables SLAB has sophisticated tuning abilities for each slab cache. One can manipulate the queue sizes in detail. However, filling the queues still requires the uses of the spin lock to check out slabs. SLUB has a global parameter (min_slab_order) for tuning. Increasing the minimum slab order can decrease the locking overhead. The bigger the slab order the less motions of pages between per CPU and partial lists occur and the better SLUB will be scaling. G. Slab merging We often have slab caches with similar parameters. SLUB detects those on boot up and merges them into the corresponding general caches. This leads to more effective memory use. About 50% of all caches can be eliminated through slab merging. This will also decrease slab fragmentation because partial allocated slabs can be filled up again. Slab merging can be switched off by specifying slub_nomerge on boot up. Note that merging can expose heretofore unknown bugs in the kernel because corrupted objects may now be placed differently and corrupt differing neighboring objects. Enable sanity checks to find those. H. Diagnostics The current slab diagnostics are difficult to use and require a recompilation of the kernel. SLUB contains debugging code that is always available (but is kept out of the hot code paths). SLUB diagnostics can be enabled via the "slab_debug" option. Parameters can be specified to select a single or a group of slab caches for diagnostics. This means that the system is running with the usual performance and it is much more likely that race conditions can be reproduced. I. Resiliency If basic sanity checks are on then SLUB is capable of detecting common error conditions and recover as best as possible to allow the system to continue. J. Tracing Tracing can be enabled via the slab_debug=T,<slabcache> option during boot. SLUB will then protocol all actions on that slabcache and dump the object contents on free. K. On demand DMA cache creation. Generally DMA caches are not needed. If a kmalloc is used with __GFP_DMA then just create this single slabcache that is needed. For systems that have no ZONE_DMA requirement the support is completely eliminated. L. Performance increase Some benchmarks have shown speed improvements on kernbench in the range of 5-10%. The locking overhead of slub is based on the underlying base allocation size. If we can reliably allocate larger order pages then it is possible to increase slub performance much further. The anti-fragmentation patches may enable further performance increases. Tested on: i386 UP + SMP, x86_64 UP + SMP + NUMA emulation, IA64 NUMA + Simulator SLUB Boot options slub_nomerge Disable merging of slabs slub_min_order=x Require a minimum order for slab caches. This increases the managed chunk size and therefore reduces meta data and locking overhead. slub_min_objects=x Mininum objects per slab. Default is 8. slub_max_order=x Avoid generating slabs larger than order specified. slub_debug Enable all diagnostics for all caches slub_debug=<options> Enable selective options for all caches slub_debug=<o>,<cache> Enable selective options for a certain set of caches Available Debug options F Double Free checking, sanity and resiliency R Red zoning P Object / padding poisoning U Track last free / alloc T Trace all allocs / frees (only use for individual slabs). To use SLUB: Apply this patch and then select SLUB as the default slab allocator. [hugh@veritas.com: fix an oops-causing locking error] [akpm@linux-foundation.org: various stupid cleanups and small fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 05:49:36 +08:00
config SLUB
bool "SLUB (Unqueued Allocator)"
mm: SLUB hardened usercopy support Under CONFIG_HARDENED_USERCOPY, this adds object size checking to the SLUB allocator to catch any copies that may span objects. Includes a redzone handling fix discovered by Michael Ellerman. Based on code from PaX and grsecurity. Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Reviwed-by: Laura Abbott <labbott@redhat.com>
2016-06-24 06:24:05 +08:00
select HAVE_HARDENED_USERCOPY_ALLOCATOR
SLUB core This is a new slab allocator which was motivated by the complexity of the existing code in mm/slab.c. It attempts to address a variety of concerns with the existing implementation. A. Management of object queues A particular concern was the complex management of the numerous object queues in SLAB. SLUB has no such queues. Instead we dedicate a slab for each allocating CPU and use objects from a slab directly instead of queueing them up. B. Storage overhead of object queues SLAB Object queues exist per node, per CPU. The alien cache queue even has a queue array that contain a queue for each processor on each node. For very large systems the number of queues and the number of objects that may be caught in those queues grows exponentially. On our systems with 1k nodes / processors we have several gigabytes just tied up for storing references to objects for those queues This does not include the objects that could be on those queues. One fears that the whole memory of the machine could one day be consumed by those queues. C. SLAB meta data overhead SLAB has overhead at the beginning of each slab. This means that data cannot be naturally aligned at the beginning of a slab block. SLUB keeps all meta data in the corresponding page_struct. Objects can be naturally aligned in the slab. F.e. a 128 byte object will be aligned at 128 byte boundaries and can fit tightly into a 4k page with no bytes left over. SLAB cannot do this. D. SLAB has a complex cache reaper SLUB does not need a cache reaper for UP systems. On SMP systems the per CPU slab may be pushed back into partial list but that operation is simple and does not require an iteration over a list of objects. SLAB expires per CPU, shared and alien object queues during cache reaping which may cause strange hold offs. E. SLAB has complex NUMA policy layer support SLUB pushes NUMA policy handling into the page allocator. This means that allocation is coarser (SLUB does interleave on a page level) but that situation was also present before 2.6.13. SLABs application of policies to individual slab objects allocated in SLAB is certainly a performance concern due to the frequent references to memory policies which may lead a sequence of objects to come from one node after another. SLUB will get a slab full of objects from one node and then will switch to the next. F. Reduction of the size of partial slab lists SLAB has per node partial lists. This means that over time a large number of partial slabs may accumulate on those lists. These can only be reused if allocator occur on specific nodes. SLUB has a global pool of partial slabs and will consume slabs from that pool to decrease fragmentation. G. Tunables SLAB has sophisticated tuning abilities for each slab cache. One can manipulate the queue sizes in detail. However, filling the queues still requires the uses of the spin lock to check out slabs. SLUB has a global parameter (min_slab_order) for tuning. Increasing the minimum slab order can decrease the locking overhead. The bigger the slab order the less motions of pages between per CPU and partial lists occur and the better SLUB will be scaling. G. Slab merging We often have slab caches with similar parameters. SLUB detects those on boot up and merges them into the corresponding general caches. This leads to more effective memory use. About 50% of all caches can be eliminated through slab merging. This will also decrease slab fragmentation because partial allocated slabs can be filled up again. Slab merging can be switched off by specifying slub_nomerge on boot up. Note that merging can expose heretofore unknown bugs in the kernel because corrupted objects may now be placed differently and corrupt differing neighboring objects. Enable sanity checks to find those. H. Diagnostics The current slab diagnostics are difficult to use and require a recompilation of the kernel. SLUB contains debugging code that is always available (but is kept out of the hot code paths). SLUB diagnostics can be enabled via the "slab_debug" option. Parameters can be specified to select a single or a group of slab caches for diagnostics. This means that the system is running with the usual performance and it is much more likely that race conditions can be reproduced. I. Resiliency If basic sanity checks are on then SLUB is capable of detecting common error conditions and recover as best as possible to allow the system to continue. J. Tracing Tracing can be enabled via the slab_debug=T,<slabcache> option during boot. SLUB will then protocol all actions on that slabcache and dump the object contents on free. K. On demand DMA cache creation. Generally DMA caches are not needed. If a kmalloc is used with __GFP_DMA then just create this single slabcache that is needed. For systems that have no ZONE_DMA requirement the support is completely eliminated. L. Performance increase Some benchmarks have shown speed improvements on kernbench in the range of 5-10%. The locking overhead of slub is based on the underlying base allocation size. If we can reliably allocate larger order pages then it is possible to increase slub performance much further. The anti-fragmentation patches may enable further performance increases. Tested on: i386 UP + SMP, x86_64 UP + SMP + NUMA emulation, IA64 NUMA + Simulator SLUB Boot options slub_nomerge Disable merging of slabs slub_min_order=x Require a minimum order for slab caches. This increases the managed chunk size and therefore reduces meta data and locking overhead. slub_min_objects=x Mininum objects per slab. Default is 8. slub_max_order=x Avoid generating slabs larger than order specified. slub_debug Enable all diagnostics for all caches slub_debug=<options> Enable selective options for all caches slub_debug=<o>,<cache> Enable selective options for a certain set of caches Available Debug options F Double Free checking, sanity and resiliency R Red zoning P Object / padding poisoning U Track last free / alloc T Trace all allocs / frees (only use for individual slabs). To use SLUB: Apply this patch and then select SLUB as the default slab allocator. [hugh@veritas.com: fix an oops-causing locking error] [akpm@linux-foundation.org: various stupid cleanups and small fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 05:49:36 +08:00
help
SLUB is a slab allocator that minimizes cache line usage
instead of managing queues of cached objects (SLAB approach).
Per cpu caching is realized using slabs of objects instead
of queues of objects. SLUB can use memory efficiently
Kconfig: SLUB is the default slab allocator In 2007, a0acd820807680d2ccc4ef3448387fcdbf152c73 changed the default slab allocator to SLUB, but the SLAB help text still says SLAB is the default. This change fixes that. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-11-06 06:18:19 +08:00
and has enhanced diagnostics. SLUB is the default choice for
a slab allocator.
SLUB core This is a new slab allocator which was motivated by the complexity of the existing code in mm/slab.c. It attempts to address a variety of concerns with the existing implementation. A. Management of object queues A particular concern was the complex management of the numerous object queues in SLAB. SLUB has no such queues. Instead we dedicate a slab for each allocating CPU and use objects from a slab directly instead of queueing them up. B. Storage overhead of object queues SLAB Object queues exist per node, per CPU. The alien cache queue even has a queue array that contain a queue for each processor on each node. For very large systems the number of queues and the number of objects that may be caught in those queues grows exponentially. On our systems with 1k nodes / processors we have several gigabytes just tied up for storing references to objects for those queues This does not include the objects that could be on those queues. One fears that the whole memory of the machine could one day be consumed by those queues. C. SLAB meta data overhead SLAB has overhead at the beginning of each slab. This means that data cannot be naturally aligned at the beginning of a slab block. SLUB keeps all meta data in the corresponding page_struct. Objects can be naturally aligned in the slab. F.e. a 128 byte object will be aligned at 128 byte boundaries and can fit tightly into a 4k page with no bytes left over. SLAB cannot do this. D. SLAB has a complex cache reaper SLUB does not need a cache reaper for UP systems. On SMP systems the per CPU slab may be pushed back into partial list but that operation is simple and does not require an iteration over a list of objects. SLAB expires per CPU, shared and alien object queues during cache reaping which may cause strange hold offs. E. SLAB has complex NUMA policy layer support SLUB pushes NUMA policy handling into the page allocator. This means that allocation is coarser (SLUB does interleave on a page level) but that situation was also present before 2.6.13. SLABs application of policies to individual slab objects allocated in SLAB is certainly a performance concern due to the frequent references to memory policies which may lead a sequence of objects to come from one node after another. SLUB will get a slab full of objects from one node and then will switch to the next. F. Reduction of the size of partial slab lists SLAB has per node partial lists. This means that over time a large number of partial slabs may accumulate on those lists. These can only be reused if allocator occur on specific nodes. SLUB has a global pool of partial slabs and will consume slabs from that pool to decrease fragmentation. G. Tunables SLAB has sophisticated tuning abilities for each slab cache. One can manipulate the queue sizes in detail. However, filling the queues still requires the uses of the spin lock to check out slabs. SLUB has a global parameter (min_slab_order) for tuning. Increasing the minimum slab order can decrease the locking overhead. The bigger the slab order the less motions of pages between per CPU and partial lists occur and the better SLUB will be scaling. G. Slab merging We often have slab caches with similar parameters. SLUB detects those on boot up and merges them into the corresponding general caches. This leads to more effective memory use. About 50% of all caches can be eliminated through slab merging. This will also decrease slab fragmentation because partial allocated slabs can be filled up again. Slab merging can be switched off by specifying slub_nomerge on boot up. Note that merging can expose heretofore unknown bugs in the kernel because corrupted objects may now be placed differently and corrupt differing neighboring objects. Enable sanity checks to find those. H. Diagnostics The current slab diagnostics are difficult to use and require a recompilation of the kernel. SLUB contains debugging code that is always available (but is kept out of the hot code paths). SLUB diagnostics can be enabled via the "slab_debug" option. Parameters can be specified to select a single or a group of slab caches for diagnostics. This means that the system is running with the usual performance and it is much more likely that race conditions can be reproduced. I. Resiliency If basic sanity checks are on then SLUB is capable of detecting common error conditions and recover as best as possible to allow the system to continue. J. Tracing Tracing can be enabled via the slab_debug=T,<slabcache> option during boot. SLUB will then protocol all actions on that slabcache and dump the object contents on free. K. On demand DMA cache creation. Generally DMA caches are not needed. If a kmalloc is used with __GFP_DMA then just create this single slabcache that is needed. For systems that have no ZONE_DMA requirement the support is completely eliminated. L. Performance increase Some benchmarks have shown speed improvements on kernbench in the range of 5-10%. The locking overhead of slub is based on the underlying base allocation size. If we can reliably allocate larger order pages then it is possible to increase slub performance much further. The anti-fragmentation patches may enable further performance increases. Tested on: i386 UP + SMP, x86_64 UP + SMP + NUMA emulation, IA64 NUMA + Simulator SLUB Boot options slub_nomerge Disable merging of slabs slub_min_order=x Require a minimum order for slab caches. This increases the managed chunk size and therefore reduces meta data and locking overhead. slub_min_objects=x Mininum objects per slab. Default is 8. slub_max_order=x Avoid generating slabs larger than order specified. slub_debug Enable all diagnostics for all caches slub_debug=<options> Enable selective options for all caches slub_debug=<o>,<cache> Enable selective options for a certain set of caches Available Debug options F Double Free checking, sanity and resiliency R Red zoning P Object / padding poisoning U Track last free / alloc T Trace all allocs / frees (only use for individual slabs). To use SLUB: Apply this patch and then select SLUB as the default slab allocator. [hugh@veritas.com: fix an oops-causing locking error] [akpm@linux-foundation.org: various stupid cleanups and small fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 05:49:36 +08:00
config SLOB
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
depends on EXPERT
SLUB core This is a new slab allocator which was motivated by the complexity of the existing code in mm/slab.c. It attempts to address a variety of concerns with the existing implementation. A. Management of object queues A particular concern was the complex management of the numerous object queues in SLAB. SLUB has no such queues. Instead we dedicate a slab for each allocating CPU and use objects from a slab directly instead of queueing them up. B. Storage overhead of object queues SLAB Object queues exist per node, per CPU. The alien cache queue even has a queue array that contain a queue for each processor on each node. For very large systems the number of queues and the number of objects that may be caught in those queues grows exponentially. On our systems with 1k nodes / processors we have several gigabytes just tied up for storing references to objects for those queues This does not include the objects that could be on those queues. One fears that the whole memory of the machine could one day be consumed by those queues. C. SLAB meta data overhead SLAB has overhead at the beginning of each slab. This means that data cannot be naturally aligned at the beginning of a slab block. SLUB keeps all meta data in the corresponding page_struct. Objects can be naturally aligned in the slab. F.e. a 128 byte object will be aligned at 128 byte boundaries and can fit tightly into a 4k page with no bytes left over. SLAB cannot do this. D. SLAB has a complex cache reaper SLUB does not need a cache reaper for UP systems. On SMP systems the per CPU slab may be pushed back into partial list but that operation is simple and does not require an iteration over a list of objects. SLAB expires per CPU, shared and alien object queues during cache reaping which may cause strange hold offs. E. SLAB has complex NUMA policy layer support SLUB pushes NUMA policy handling into the page allocator. This means that allocation is coarser (SLUB does interleave on a page level) but that situation was also present before 2.6.13. SLABs application of policies to individual slab objects allocated in SLAB is certainly a performance concern due to the frequent references to memory policies which may lead a sequence of objects to come from one node after another. SLUB will get a slab full of objects from one node and then will switch to the next. F. Reduction of the size of partial slab lists SLAB has per node partial lists. This means that over time a large number of partial slabs may accumulate on those lists. These can only be reused if allocator occur on specific nodes. SLUB has a global pool of partial slabs and will consume slabs from that pool to decrease fragmentation. G. Tunables SLAB has sophisticated tuning abilities for each slab cache. One can manipulate the queue sizes in detail. However, filling the queues still requires the uses of the spin lock to check out slabs. SLUB has a global parameter (min_slab_order) for tuning. Increasing the minimum slab order can decrease the locking overhead. The bigger the slab order the less motions of pages between per CPU and partial lists occur and the better SLUB will be scaling. G. Slab merging We often have slab caches with similar parameters. SLUB detects those on boot up and merges them into the corresponding general caches. This leads to more effective memory use. About 50% of all caches can be eliminated through slab merging. This will also decrease slab fragmentation because partial allocated slabs can be filled up again. Slab merging can be switched off by specifying slub_nomerge on boot up. Note that merging can expose heretofore unknown bugs in the kernel because corrupted objects may now be placed differently and corrupt differing neighboring objects. Enable sanity checks to find those. H. Diagnostics The current slab diagnostics are difficult to use and require a recompilation of the kernel. SLUB contains debugging code that is always available (but is kept out of the hot code paths). SLUB diagnostics can be enabled via the "slab_debug" option. Parameters can be specified to select a single or a group of slab caches for diagnostics. This means that the system is running with the usual performance and it is much more likely that race conditions can be reproduced. I. Resiliency If basic sanity checks are on then SLUB is capable of detecting common error conditions and recover as best as possible to allow the system to continue. J. Tracing Tracing can be enabled via the slab_debug=T,<slabcache> option during boot. SLUB will then protocol all actions on that slabcache and dump the object contents on free. K. On demand DMA cache creation. Generally DMA caches are not needed. If a kmalloc is used with __GFP_DMA then just create this single slabcache that is needed. For systems that have no ZONE_DMA requirement the support is completely eliminated. L. Performance increase Some benchmarks have shown speed improvements on kernbench in the range of 5-10%. The locking overhead of slub is based on the underlying base allocation size. If we can reliably allocate larger order pages then it is possible to increase slub performance much further. The anti-fragmentation patches may enable further performance increases. Tested on: i386 UP + SMP, x86_64 UP + SMP + NUMA emulation, IA64 NUMA + Simulator SLUB Boot options slub_nomerge Disable merging of slabs slub_min_order=x Require a minimum order for slab caches. This increases the managed chunk size and therefore reduces meta data and locking overhead. slub_min_objects=x Mininum objects per slab. Default is 8. slub_max_order=x Avoid generating slabs larger than order specified. slub_debug Enable all diagnostics for all caches slub_debug=<options> Enable selective options for all caches slub_debug=<o>,<cache> Enable selective options for a certain set of caches Available Debug options F Double Free checking, sanity and resiliency R Red zoning P Object / padding poisoning U Track last free / alloc T Trace all allocs / frees (only use for individual slabs). To use SLUB: Apply this patch and then select SLUB as the default slab allocator. [hugh@veritas.com: fix an oops-causing locking error] [akpm@linux-foundation.org: various stupid cleanups and small fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 05:49:36 +08:00
bool "SLOB (Simple Allocator)"
help
slob: correct Kconfig description Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 14:29:38 +08:00
SLOB replaces the stock allocator with a drastically simpler
allocator. SLOB is generally more space efficient but
does not perform as well on large systems.
SLUB core This is a new slab allocator which was motivated by the complexity of the existing code in mm/slab.c. It attempts to address a variety of concerns with the existing implementation. A. Management of object queues A particular concern was the complex management of the numerous object queues in SLAB. SLUB has no such queues. Instead we dedicate a slab for each allocating CPU and use objects from a slab directly instead of queueing them up. B. Storage overhead of object queues SLAB Object queues exist per node, per CPU. The alien cache queue even has a queue array that contain a queue for each processor on each node. For very large systems the number of queues and the number of objects that may be caught in those queues grows exponentially. On our systems with 1k nodes / processors we have several gigabytes just tied up for storing references to objects for those queues This does not include the objects that could be on those queues. One fears that the whole memory of the machine could one day be consumed by those queues. C. SLAB meta data overhead SLAB has overhead at the beginning of each slab. This means that data cannot be naturally aligned at the beginning of a slab block. SLUB keeps all meta data in the corresponding page_struct. Objects can be naturally aligned in the slab. F.e. a 128 byte object will be aligned at 128 byte boundaries and can fit tightly into a 4k page with no bytes left over. SLAB cannot do this. D. SLAB has a complex cache reaper SLUB does not need a cache reaper for UP systems. On SMP systems the per CPU slab may be pushed back into partial list but that operation is simple and does not require an iteration over a list of objects. SLAB expires per CPU, shared and alien object queues during cache reaping which may cause strange hold offs. E. SLAB has complex NUMA policy layer support SLUB pushes NUMA policy handling into the page allocator. This means that allocation is coarser (SLUB does interleave on a page level) but that situation was also present before 2.6.13. SLABs application of policies to individual slab objects allocated in SLAB is certainly a performance concern due to the frequent references to memory policies which may lead a sequence of objects to come from one node after another. SLUB will get a slab full of objects from one node and then will switch to the next. F. Reduction of the size of partial slab lists SLAB has per node partial lists. This means that over time a large number of partial slabs may accumulate on those lists. These can only be reused if allocator occur on specific nodes. SLUB has a global pool of partial slabs and will consume slabs from that pool to decrease fragmentation. G. Tunables SLAB has sophisticated tuning abilities for each slab cache. One can manipulate the queue sizes in detail. However, filling the queues still requires the uses of the spin lock to check out slabs. SLUB has a global parameter (min_slab_order) for tuning. Increasing the minimum slab order can decrease the locking overhead. The bigger the slab order the less motions of pages between per CPU and partial lists occur and the better SLUB will be scaling. G. Slab merging We often have slab caches with similar parameters. SLUB detects those on boot up and merges them into the corresponding general caches. This leads to more effective memory use. About 50% of all caches can be eliminated through slab merging. This will also decrease slab fragmentation because partial allocated slabs can be filled up again. Slab merging can be switched off by specifying slub_nomerge on boot up. Note that merging can expose heretofore unknown bugs in the kernel because corrupted objects may now be placed differently and corrupt differing neighboring objects. Enable sanity checks to find those. H. Diagnostics The current slab diagnostics are difficult to use and require a recompilation of the kernel. SLUB contains debugging code that is always available (but is kept out of the hot code paths). SLUB diagnostics can be enabled via the "slab_debug" option. Parameters can be specified to select a single or a group of slab caches for diagnostics. This means that the system is running with the usual performance and it is much more likely that race conditions can be reproduced. I. Resiliency If basic sanity checks are on then SLUB is capable of detecting common error conditions and recover as best as possible to allow the system to continue. J. Tracing Tracing can be enabled via the slab_debug=T,<slabcache> option during boot. SLUB will then protocol all actions on that slabcache and dump the object contents on free. K. On demand DMA cache creation. Generally DMA caches are not needed. If a kmalloc is used with __GFP_DMA then just create this single slabcache that is needed. For systems that have no ZONE_DMA requirement the support is completely eliminated. L. Performance increase Some benchmarks have shown speed improvements on kernbench in the range of 5-10%. The locking overhead of slub is based on the underlying base allocation size. If we can reliably allocate larger order pages then it is possible to increase slub performance much further. The anti-fragmentation patches may enable further performance increases. Tested on: i386 UP + SMP, x86_64 UP + SMP + NUMA emulation, IA64 NUMA + Simulator SLUB Boot options slub_nomerge Disable merging of slabs slub_min_order=x Require a minimum order for slab caches. This increases the managed chunk size and therefore reduces meta data and locking overhead. slub_min_objects=x Mininum objects per slab. Default is 8. slub_max_order=x Avoid generating slabs larger than order specified. slub_debug Enable all diagnostics for all caches slub_debug=<options> Enable selective options for all caches slub_debug=<o>,<cache> Enable selective options for a certain set of caches Available Debug options F Double Free checking, sanity and resiliency R Red zoning P Object / padding poisoning U Track last free / alloc T Trace all allocs / frees (only use for individual slabs). To use SLUB: Apply this patch and then select SLUB as the default slab allocator. [hugh@veritas.com: fix an oops-causing locking error] [akpm@linux-foundation.org: various stupid cleanups and small fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 05:49:36 +08:00
endchoice
mm: allow slab_nomerge to be set at build time Some hardened environments want to build kernels with slab_nomerge already set (so that they do not depend on remembering to set the kernel command line option). This is desired to reduce the risk of kernel heap overflows being able to overwrite objects from merged caches and changes the requirements for cache layout control, increasing the difficulty of these attacks. By keeping caches unmerged, these kinds of exploits can usually only damage objects in the same cache (though the risk to metadata exploitation is unchanged). Link: http://lkml.kernel.org/r/20170620230911.GA25238@beast Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Daniel Micay <danielmicay@gmail.com> Cc: David Windsor <dave@nullcore.net> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Daniel Micay <danielmicay@gmail.com> Cc: David Windsor <dave@nullcore.net> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Tejun Heo <tj@kernel.org> Cc: Daniel Mack <daniel@zonque.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Helge Deller <deller@gmx.de> Cc: Rik van Riel <riel@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07 06:36:40 +08:00
config SLAB_MERGE_DEFAULT
bool "Allow slab caches to be merged"
default y
help
For reduced kernel memory fragmentation, slab caches can be
merged when they share the same size and other characteristics.
This carries a risk of kernel heap overflows being able to
overwrite objects from merged caches (and more easily control
cache layout), which makes such heap attacks easier to exploit
by attackers. By keeping caches unmerged, these kinds of exploits
can usually only damage objects in the same cache. To disable
merging at runtime, "slab_nomerge" can be passed on the kernel
command line.
mm: SLAB freelist randomization Provides an optional config (CONFIG_SLAB_FREELIST_RANDOM) to randomize the SLAB freelist. The list is randomized during initialization of a new set of pages. The order on different freelist sizes is pre-computed at boot for performance. Each kmem_cache has its own randomized freelist. Before pre-computed lists are available freelists are generated dynamically. This security feature reduces the predictability of the kernel SLAB allocator against heap overflows rendering attacks much less stable. For example this attack against SLUB (also applicable against SLAB) would be affected: https://jon.oberheide.org/blog/2010/09/10/linux-kernel-can-slub-overflow/ Also, since v4.6 the freelist was moved at the end of the SLAB. It means a controllable heap is opened to new attacks not yet publicly discussed. A kernel heap overflow can be transformed to multiple use-after-free. This feature makes this type of attack harder too. To generate entropy, we use get_random_bytes_arch because 0 bits of entropy is available in the boot stage. In the worse case this function will fallback to the get_random_bytes sub API. We also generate a shift random number to shift pre-computed freelist for each new set of pages. The config option name is not specific to the SLAB as this approach will be extended to other allocators like SLUB. Performance results highlighted no major changes: Hackbench (running 90 10 times): Before average: 0.0698 After average: 0.0663 (-5.01%) slab_test 1 run on boot. Difference only seen on the 2048 size test being the worse case scenario covered by freelist randomization. New slab pages are constantly being created on the 10000 allocations. Variance should be mainly due to getting new pages every few allocations. Before: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 10000 times kmalloc(8) -> 99 cycles kfree -> 112 cycles 10000 times kmalloc(16) -> 109 cycles kfree -> 140 cycles 10000 times kmalloc(32) -> 129 cycles kfree -> 137 cycles 10000 times kmalloc(64) -> 141 cycles kfree -> 141 cycles 10000 times kmalloc(128) -> 152 cycles kfree -> 148 cycles 10000 times kmalloc(256) -> 195 cycles kfree -> 167 cycles 10000 times kmalloc(512) -> 257 cycles kfree -> 199 cycles 10000 times kmalloc(1024) -> 393 cycles kfree -> 251 cycles 10000 times kmalloc(2048) -> 649 cycles kfree -> 228 cycles 10000 times kmalloc(4096) -> 806 cycles kfree -> 370 cycles 10000 times kmalloc(8192) -> 814 cycles kfree -> 411 cycles 10000 times kmalloc(16384) -> 892 cycles kfree -> 455 cycles 2. Kmalloc: alloc/free test 10000 times kmalloc(8)/kfree -> 121 cycles 10000 times kmalloc(16)/kfree -> 121 cycles 10000 times kmalloc(32)/kfree -> 121 cycles 10000 times kmalloc(64)/kfree -> 121 cycles 10000 times kmalloc(128)/kfree -> 121 cycles 10000 times kmalloc(256)/kfree -> 119 cycles 10000 times kmalloc(512)/kfree -> 119 cycles 10000 times kmalloc(1024)/kfree -> 119 cycles 10000 times kmalloc(2048)/kfree -> 119 cycles 10000 times kmalloc(4096)/kfree -> 121 cycles 10000 times kmalloc(8192)/kfree -> 119 cycles 10000 times kmalloc(16384)/kfree -> 119 cycles After: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 10000 times kmalloc(8) -> 130 cycles kfree -> 86 cycles 10000 times kmalloc(16) -> 118 cycles kfree -> 86 cycles 10000 times kmalloc(32) -> 121 cycles kfree -> 85 cycles 10000 times kmalloc(64) -> 176 cycles kfree -> 102 cycles 10000 times kmalloc(128) -> 178 cycles kfree -> 100 cycles 10000 times kmalloc(256) -> 205 cycles kfree -> 109 cycles 10000 times kmalloc(512) -> 262 cycles kfree -> 136 cycles 10000 times kmalloc(1024) -> 342 cycles kfree -> 157 cycles 10000 times kmalloc(2048) -> 701 cycles kfree -> 238 cycles 10000 times kmalloc(4096) -> 803 cycles kfree -> 364 cycles 10000 times kmalloc(8192) -> 835 cycles kfree -> 404 cycles 10000 times kmalloc(16384) -> 896 cycles kfree -> 441 cycles 2. Kmalloc: alloc/free test 10000 times kmalloc(8)/kfree -> 121 cycles 10000 times kmalloc(16)/kfree -> 121 cycles 10000 times kmalloc(32)/kfree -> 123 cycles 10000 times kmalloc(64)/kfree -> 142 cycles 10000 times kmalloc(128)/kfree -> 121 cycles 10000 times kmalloc(256)/kfree -> 119 cycles 10000 times kmalloc(512)/kfree -> 119 cycles 10000 times kmalloc(1024)/kfree -> 119 cycles 10000 times kmalloc(2048)/kfree -> 119 cycles 10000 times kmalloc(4096)/kfree -> 119 cycles 10000 times kmalloc(8192)/kfree -> 119 cycles 10000 times kmalloc(16384)/kfree -> 119 cycles [akpm@linux-foundation.org: propagate gfp_t into cache_random_seq_create()] Signed-off-by: Thomas Garnier <thgarnie@google.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Greg Thelen <gthelen@google.com> Cc: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 08:10:37 +08:00
config SLAB_FREELIST_RANDOM
default n
mm: SLUB freelist randomization Implements freelist randomization for the SLUB allocator. It was previous implemented for the SLAB allocator. Both use the same configuration option (CONFIG_SLAB_FREELIST_RANDOM). The list is randomized during initialization of a new set of pages. The order on different freelist sizes is pre-computed at boot for performance. Each kmem_cache has its own randomized freelist. This security feature reduces the predictability of the kernel SLUB allocator against heap overflows rendering attacks much less stable. For example these attacks exploit the predictability of the heap: - Linux Kernel CAN SLUB overflow (https://goo.gl/oMNWkU) - Exploiting Linux Kernel Heap corruptions (http://goo.gl/EXLn95) Performance results: slab_test impact is between 3% to 4% on average for 100000 attempts without smp. It is a very focused testing, kernbench show the overall impact on the system is way lower. Before: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 100000 times kmalloc(8) -> 49 cycles kfree -> 77 cycles 100000 times kmalloc(16) -> 51 cycles kfree -> 79 cycles 100000 times kmalloc(32) -> 53 cycles kfree -> 83 cycles 100000 times kmalloc(64) -> 62 cycles kfree -> 90 cycles 100000 times kmalloc(128) -> 81 cycles kfree -> 97 cycles 100000 times kmalloc(256) -> 98 cycles kfree -> 121 cycles 100000 times kmalloc(512) -> 95 cycles kfree -> 122 cycles 100000 times kmalloc(1024) -> 96 cycles kfree -> 126 cycles 100000 times kmalloc(2048) -> 115 cycles kfree -> 140 cycles 100000 times kmalloc(4096) -> 149 cycles kfree -> 171 cycles 2. Kmalloc: alloc/free test 100000 times kmalloc(8)/kfree -> 70 cycles 100000 times kmalloc(16)/kfree -> 70 cycles 100000 times kmalloc(32)/kfree -> 70 cycles 100000 times kmalloc(64)/kfree -> 70 cycles 100000 times kmalloc(128)/kfree -> 70 cycles 100000 times kmalloc(256)/kfree -> 69 cycles 100000 times kmalloc(512)/kfree -> 70 cycles 100000 times kmalloc(1024)/kfree -> 73 cycles 100000 times kmalloc(2048)/kfree -> 72 cycles 100000 times kmalloc(4096)/kfree -> 71 cycles After: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 100000 times kmalloc(8) -> 57 cycles kfree -> 78 cycles 100000 times kmalloc(16) -> 61 cycles kfree -> 81 cycles 100000 times kmalloc(32) -> 76 cycles kfree -> 93 cycles 100000 times kmalloc(64) -> 83 cycles kfree -> 94 cycles 100000 times kmalloc(128) -> 106 cycles kfree -> 107 cycles 100000 times kmalloc(256) -> 118 cycles kfree -> 117 cycles 100000 times kmalloc(512) -> 114 cycles kfree -> 116 cycles 100000 times kmalloc(1024) -> 115 cycles kfree -> 118 cycles 100000 times kmalloc(2048) -> 147 cycles kfree -> 131 cycles 100000 times kmalloc(4096) -> 214 cycles kfree -> 161 cycles 2. Kmalloc: alloc/free test 100000 times kmalloc(8)/kfree -> 66 cycles 100000 times kmalloc(16)/kfree -> 66 cycles 100000 times kmalloc(32)/kfree -> 66 cycles 100000 times kmalloc(64)/kfree -> 66 cycles 100000 times kmalloc(128)/kfree -> 65 cycles 100000 times kmalloc(256)/kfree -> 67 cycles 100000 times kmalloc(512)/kfree -> 67 cycles 100000 times kmalloc(1024)/kfree -> 64 cycles 100000 times kmalloc(2048)/kfree -> 67 cycles 100000 times kmalloc(4096)/kfree -> 67 cycles Kernbench, before: Average Optimal load -j 12 Run (std deviation): Elapsed Time 101.873 (1.16069) User Time 1045.22 (1.60447) System Time 88.969 (0.559195) Percent CPU 1112.9 (13.8279) Context Switches 189140 (2282.15) Sleeps 99008.6 (768.091) After: Average Optimal load -j 12 Run (std deviation): Elapsed Time 102.47 (0.562732) User Time 1045.3 (1.34263) System Time 88.311 (0.342554) Percent CPU 1105.8 (6.49444) Context Switches 189081 (2355.78) Sleeps 99231.5 (800.358) Link: http://lkml.kernel.org/r/1464295031-26375-3-git-send-email-thgarnie@google.com Signed-off-by: Thomas Garnier <thgarnie@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 06:21:59 +08:00
depends on SLAB || SLUB
mm: SLAB freelist randomization Provides an optional config (CONFIG_SLAB_FREELIST_RANDOM) to randomize the SLAB freelist. The list is randomized during initialization of a new set of pages. The order on different freelist sizes is pre-computed at boot for performance. Each kmem_cache has its own randomized freelist. Before pre-computed lists are available freelists are generated dynamically. This security feature reduces the predictability of the kernel SLAB allocator against heap overflows rendering attacks much less stable. For example this attack against SLUB (also applicable against SLAB) would be affected: https://jon.oberheide.org/blog/2010/09/10/linux-kernel-can-slub-overflow/ Also, since v4.6 the freelist was moved at the end of the SLAB. It means a controllable heap is opened to new attacks not yet publicly discussed. A kernel heap overflow can be transformed to multiple use-after-free. This feature makes this type of attack harder too. To generate entropy, we use get_random_bytes_arch because 0 bits of entropy is available in the boot stage. In the worse case this function will fallback to the get_random_bytes sub API. We also generate a shift random number to shift pre-computed freelist for each new set of pages. The config option name is not specific to the SLAB as this approach will be extended to other allocators like SLUB. Performance results highlighted no major changes: Hackbench (running 90 10 times): Before average: 0.0698 After average: 0.0663 (-5.01%) slab_test 1 run on boot. Difference only seen on the 2048 size test being the worse case scenario covered by freelist randomization. New slab pages are constantly being created on the 10000 allocations. Variance should be mainly due to getting new pages every few allocations. Before: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 10000 times kmalloc(8) -> 99 cycles kfree -> 112 cycles 10000 times kmalloc(16) -> 109 cycles kfree -> 140 cycles 10000 times kmalloc(32) -> 129 cycles kfree -> 137 cycles 10000 times kmalloc(64) -> 141 cycles kfree -> 141 cycles 10000 times kmalloc(128) -> 152 cycles kfree -> 148 cycles 10000 times kmalloc(256) -> 195 cycles kfree -> 167 cycles 10000 times kmalloc(512) -> 257 cycles kfree -> 199 cycles 10000 times kmalloc(1024) -> 393 cycles kfree -> 251 cycles 10000 times kmalloc(2048) -> 649 cycles kfree -> 228 cycles 10000 times kmalloc(4096) -> 806 cycles kfree -> 370 cycles 10000 times kmalloc(8192) -> 814 cycles kfree -> 411 cycles 10000 times kmalloc(16384) -> 892 cycles kfree -> 455 cycles 2. Kmalloc: alloc/free test 10000 times kmalloc(8)/kfree -> 121 cycles 10000 times kmalloc(16)/kfree -> 121 cycles 10000 times kmalloc(32)/kfree -> 121 cycles 10000 times kmalloc(64)/kfree -> 121 cycles 10000 times kmalloc(128)/kfree -> 121 cycles 10000 times kmalloc(256)/kfree -> 119 cycles 10000 times kmalloc(512)/kfree -> 119 cycles 10000 times kmalloc(1024)/kfree -> 119 cycles 10000 times kmalloc(2048)/kfree -> 119 cycles 10000 times kmalloc(4096)/kfree -> 121 cycles 10000 times kmalloc(8192)/kfree -> 119 cycles 10000 times kmalloc(16384)/kfree -> 119 cycles After: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 10000 times kmalloc(8) -> 130 cycles kfree -> 86 cycles 10000 times kmalloc(16) -> 118 cycles kfree -> 86 cycles 10000 times kmalloc(32) -> 121 cycles kfree -> 85 cycles 10000 times kmalloc(64) -> 176 cycles kfree -> 102 cycles 10000 times kmalloc(128) -> 178 cycles kfree -> 100 cycles 10000 times kmalloc(256) -> 205 cycles kfree -> 109 cycles 10000 times kmalloc(512) -> 262 cycles kfree -> 136 cycles 10000 times kmalloc(1024) -> 342 cycles kfree -> 157 cycles 10000 times kmalloc(2048) -> 701 cycles kfree -> 238 cycles 10000 times kmalloc(4096) -> 803 cycles kfree -> 364 cycles 10000 times kmalloc(8192) -> 835 cycles kfree -> 404 cycles 10000 times kmalloc(16384) -> 896 cycles kfree -> 441 cycles 2. Kmalloc: alloc/free test 10000 times kmalloc(8)/kfree -> 121 cycles 10000 times kmalloc(16)/kfree -> 121 cycles 10000 times kmalloc(32)/kfree -> 123 cycles 10000 times kmalloc(64)/kfree -> 142 cycles 10000 times kmalloc(128)/kfree -> 121 cycles 10000 times kmalloc(256)/kfree -> 119 cycles 10000 times kmalloc(512)/kfree -> 119 cycles 10000 times kmalloc(1024)/kfree -> 119 cycles 10000 times kmalloc(2048)/kfree -> 119 cycles 10000 times kmalloc(4096)/kfree -> 119 cycles 10000 times kmalloc(8192)/kfree -> 119 cycles 10000 times kmalloc(16384)/kfree -> 119 cycles [akpm@linux-foundation.org: propagate gfp_t into cache_random_seq_create()] Signed-off-by: Thomas Garnier <thgarnie@google.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Greg Thelen <gthelen@google.com> Cc: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 08:10:37 +08:00
bool "SLAB freelist randomization"
help
mm: SLUB freelist randomization Implements freelist randomization for the SLUB allocator. It was previous implemented for the SLAB allocator. Both use the same configuration option (CONFIG_SLAB_FREELIST_RANDOM). The list is randomized during initialization of a new set of pages. The order on different freelist sizes is pre-computed at boot for performance. Each kmem_cache has its own randomized freelist. This security feature reduces the predictability of the kernel SLUB allocator against heap overflows rendering attacks much less stable. For example these attacks exploit the predictability of the heap: - Linux Kernel CAN SLUB overflow (https://goo.gl/oMNWkU) - Exploiting Linux Kernel Heap corruptions (http://goo.gl/EXLn95) Performance results: slab_test impact is between 3% to 4% on average for 100000 attempts without smp. It is a very focused testing, kernbench show the overall impact on the system is way lower. Before: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 100000 times kmalloc(8) -> 49 cycles kfree -> 77 cycles 100000 times kmalloc(16) -> 51 cycles kfree -> 79 cycles 100000 times kmalloc(32) -> 53 cycles kfree -> 83 cycles 100000 times kmalloc(64) -> 62 cycles kfree -> 90 cycles 100000 times kmalloc(128) -> 81 cycles kfree -> 97 cycles 100000 times kmalloc(256) -> 98 cycles kfree -> 121 cycles 100000 times kmalloc(512) -> 95 cycles kfree -> 122 cycles 100000 times kmalloc(1024) -> 96 cycles kfree -> 126 cycles 100000 times kmalloc(2048) -> 115 cycles kfree -> 140 cycles 100000 times kmalloc(4096) -> 149 cycles kfree -> 171 cycles 2. Kmalloc: alloc/free test 100000 times kmalloc(8)/kfree -> 70 cycles 100000 times kmalloc(16)/kfree -> 70 cycles 100000 times kmalloc(32)/kfree -> 70 cycles 100000 times kmalloc(64)/kfree -> 70 cycles 100000 times kmalloc(128)/kfree -> 70 cycles 100000 times kmalloc(256)/kfree -> 69 cycles 100000 times kmalloc(512)/kfree -> 70 cycles 100000 times kmalloc(1024)/kfree -> 73 cycles 100000 times kmalloc(2048)/kfree -> 72 cycles 100000 times kmalloc(4096)/kfree -> 71 cycles After: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 100000 times kmalloc(8) -> 57 cycles kfree -> 78 cycles 100000 times kmalloc(16) -> 61 cycles kfree -> 81 cycles 100000 times kmalloc(32) -> 76 cycles kfree -> 93 cycles 100000 times kmalloc(64) -> 83 cycles kfree -> 94 cycles 100000 times kmalloc(128) -> 106 cycles kfree -> 107 cycles 100000 times kmalloc(256) -> 118 cycles kfree -> 117 cycles 100000 times kmalloc(512) -> 114 cycles kfree -> 116 cycles 100000 times kmalloc(1024) -> 115 cycles kfree -> 118 cycles 100000 times kmalloc(2048) -> 147 cycles kfree -> 131 cycles 100000 times kmalloc(4096) -> 214 cycles kfree -> 161 cycles 2. Kmalloc: alloc/free test 100000 times kmalloc(8)/kfree -> 66 cycles 100000 times kmalloc(16)/kfree -> 66 cycles 100000 times kmalloc(32)/kfree -> 66 cycles 100000 times kmalloc(64)/kfree -> 66 cycles 100000 times kmalloc(128)/kfree -> 65 cycles 100000 times kmalloc(256)/kfree -> 67 cycles 100000 times kmalloc(512)/kfree -> 67 cycles 100000 times kmalloc(1024)/kfree -> 64 cycles 100000 times kmalloc(2048)/kfree -> 67 cycles 100000 times kmalloc(4096)/kfree -> 67 cycles Kernbench, before: Average Optimal load -j 12 Run (std deviation): Elapsed Time 101.873 (1.16069) User Time 1045.22 (1.60447) System Time 88.969 (0.559195) Percent CPU 1112.9 (13.8279) Context Switches 189140 (2282.15) Sleeps 99008.6 (768.091) After: Average Optimal load -j 12 Run (std deviation): Elapsed Time 102.47 (0.562732) User Time 1045.3 (1.34263) System Time 88.311 (0.342554) Percent CPU 1105.8 (6.49444) Context Switches 189081 (2355.78) Sleeps 99231.5 (800.358) Link: http://lkml.kernel.org/r/1464295031-26375-3-git-send-email-thgarnie@google.com Signed-off-by: Thomas Garnier <thgarnie@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 06:21:59 +08:00
Randomizes the freelist order used on creating new pages. This
mm: SLAB freelist randomization Provides an optional config (CONFIG_SLAB_FREELIST_RANDOM) to randomize the SLAB freelist. The list is randomized during initialization of a new set of pages. The order on different freelist sizes is pre-computed at boot for performance. Each kmem_cache has its own randomized freelist. Before pre-computed lists are available freelists are generated dynamically. This security feature reduces the predictability of the kernel SLAB allocator against heap overflows rendering attacks much less stable. For example this attack against SLUB (also applicable against SLAB) would be affected: https://jon.oberheide.org/blog/2010/09/10/linux-kernel-can-slub-overflow/ Also, since v4.6 the freelist was moved at the end of the SLAB. It means a controllable heap is opened to new attacks not yet publicly discussed. A kernel heap overflow can be transformed to multiple use-after-free. This feature makes this type of attack harder too. To generate entropy, we use get_random_bytes_arch because 0 bits of entropy is available in the boot stage. In the worse case this function will fallback to the get_random_bytes sub API. We also generate a shift random number to shift pre-computed freelist for each new set of pages. The config option name is not specific to the SLAB as this approach will be extended to other allocators like SLUB. Performance results highlighted no major changes: Hackbench (running 90 10 times): Before average: 0.0698 After average: 0.0663 (-5.01%) slab_test 1 run on boot. Difference only seen on the 2048 size test being the worse case scenario covered by freelist randomization. New slab pages are constantly being created on the 10000 allocations. Variance should be mainly due to getting new pages every few allocations. Before: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 10000 times kmalloc(8) -> 99 cycles kfree -> 112 cycles 10000 times kmalloc(16) -> 109 cycles kfree -> 140 cycles 10000 times kmalloc(32) -> 129 cycles kfree -> 137 cycles 10000 times kmalloc(64) -> 141 cycles kfree -> 141 cycles 10000 times kmalloc(128) -> 152 cycles kfree -> 148 cycles 10000 times kmalloc(256) -> 195 cycles kfree -> 167 cycles 10000 times kmalloc(512) -> 257 cycles kfree -> 199 cycles 10000 times kmalloc(1024) -> 393 cycles kfree -> 251 cycles 10000 times kmalloc(2048) -> 649 cycles kfree -> 228 cycles 10000 times kmalloc(4096) -> 806 cycles kfree -> 370 cycles 10000 times kmalloc(8192) -> 814 cycles kfree -> 411 cycles 10000 times kmalloc(16384) -> 892 cycles kfree -> 455 cycles 2. Kmalloc: alloc/free test 10000 times kmalloc(8)/kfree -> 121 cycles 10000 times kmalloc(16)/kfree -> 121 cycles 10000 times kmalloc(32)/kfree -> 121 cycles 10000 times kmalloc(64)/kfree -> 121 cycles 10000 times kmalloc(128)/kfree -> 121 cycles 10000 times kmalloc(256)/kfree -> 119 cycles 10000 times kmalloc(512)/kfree -> 119 cycles 10000 times kmalloc(1024)/kfree -> 119 cycles 10000 times kmalloc(2048)/kfree -> 119 cycles 10000 times kmalloc(4096)/kfree -> 121 cycles 10000 times kmalloc(8192)/kfree -> 119 cycles 10000 times kmalloc(16384)/kfree -> 119 cycles After: Single thread testing ===================== 1. Kmalloc: Repeatedly allocate then free test 10000 times kmalloc(8) -> 130 cycles kfree -> 86 cycles 10000 times kmalloc(16) -> 118 cycles kfree -> 86 cycles 10000 times kmalloc(32) -> 121 cycles kfree -> 85 cycles 10000 times kmalloc(64) -> 176 cycles kfree -> 102 cycles 10000 times kmalloc(128) -> 178 cycles kfree -> 100 cycles 10000 times kmalloc(256) -> 205 cycles kfree -> 109 cycles 10000 times kmalloc(512) -> 262 cycles kfree -> 136 cycles 10000 times kmalloc(1024) -> 342 cycles kfree -> 157 cycles 10000 times kmalloc(2048) -> 701 cycles kfree -> 238 cycles 10000 times kmalloc(4096) -> 803 cycles kfree -> 364 cycles 10000 times kmalloc(8192) -> 835 cycles kfree -> 404 cycles 10000 times kmalloc(16384) -> 896 cycles kfree -> 441 cycles 2. Kmalloc: alloc/free test 10000 times kmalloc(8)/kfree -> 121 cycles 10000 times kmalloc(16)/kfree -> 121 cycles 10000 times kmalloc(32)/kfree -> 123 cycles 10000 times kmalloc(64)/kfree -> 142 cycles 10000 times kmalloc(128)/kfree -> 121 cycles 10000 times kmalloc(256)/kfree -> 119 cycles 10000 times kmalloc(512)/kfree -> 119 cycles 10000 times kmalloc(1024)/kfree -> 119 cycles 10000 times kmalloc(2048)/kfree -> 119 cycles 10000 times kmalloc(4096)/kfree -> 119 cycles 10000 times kmalloc(8192)/kfree -> 119 cycles 10000 times kmalloc(16384)/kfree -> 119 cycles [akpm@linux-foundation.org: propagate gfp_t into cache_random_seq_create()] Signed-off-by: Thomas Garnier <thgarnie@google.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Greg Thelen <gthelen@google.com> Cc: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 08:10:37 +08:00
security feature reduces the predictability of the kernel slab
allocator against heap overflows.
mm: add SLUB free list pointer obfuscation This SLUB free list pointer obfuscation code is modified from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. This adds a per-cache random value to SLUB caches that is XORed with their freelist pointer address and value. This adds nearly zero overhead and frustrates the very common heap overflow exploitation method of overwriting freelist pointers. A recent example of the attack is written up here: http://cyseclabs.com/blog/cve-2016-6187-heap-off-by-one-exploit and there is a section dedicated to the technique the book "A Guide to Kernel Exploitation: Attacking the Core". This is based on patches by Daniel Micay, and refactored to minimize the use of #ifdef. With 200-count cycles of "hackbench -g 20 -l 1000" I saw the following run times: before: mean 10.11882499999999999995 variance .03320378329145728642 stdev .18221905304181911048 after: mean 10.12654000000000000014 variance .04700556623115577889 stdev .21680767106160192064 The difference gets lost in the noise, but if the above is to be taken literally, using CONFIG_FREELIST_HARDENED is 0.07% slower. Link: http://lkml.kernel.org/r/20170802180609.GA66807@beast Signed-off-by: Kees Cook <keescook@chromium.org> Suggested-by: Daniel Micay <danielmicay@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Tycho Andersen <tycho@docker.com> Cc: Alexander Popov <alex.popov@linux.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-07 07:19:18 +08:00
config SLAB_FREELIST_HARDENED
bool "Harden slab freelist metadata"
depends on SLUB
help
Many kernel heap attacks try to target slab cache metadata and
other infrastructure. This options makes minor performance
init/Kconfig: fix neighboring typos This fixes a couple typos I noticed in the slab Kconfig: sacrifies -> sacrifices accellerate -> accelerate Seeing as no other instances of these typos are found elsewhere in the kernel and that I originally added one of the two, I can only assume working on slab must have caused damage to the spelling centers of my brain. Link: http://lkml.kernel.org/r/201905292203.CD000546EB@keescook Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-17 07:27:57 +08:00
sacrifices to harden the kernel slab allocator against common
mm: add SLUB free list pointer obfuscation This SLUB free list pointer obfuscation code is modified from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. This adds a per-cache random value to SLUB caches that is XORed with their freelist pointer address and value. This adds nearly zero overhead and frustrates the very common heap overflow exploitation method of overwriting freelist pointers. A recent example of the attack is written up here: http://cyseclabs.com/blog/cve-2016-6187-heap-off-by-one-exploit and there is a section dedicated to the technique the book "A Guide to Kernel Exploitation: Attacking the Core". This is based on patches by Daniel Micay, and refactored to minimize the use of #ifdef. With 200-count cycles of "hackbench -g 20 -l 1000" I saw the following run times: before: mean 10.11882499999999999995 variance .03320378329145728642 stdev .18221905304181911048 after: mean 10.12654000000000000014 variance .04700556623115577889 stdev .21680767106160192064 The difference gets lost in the noise, but if the above is to be taken literally, using CONFIG_FREELIST_HARDENED is 0.07% slower. Link: http://lkml.kernel.org/r/20170802180609.GA66807@beast Signed-off-by: Kees Cook <keescook@chromium.org> Suggested-by: Daniel Micay <danielmicay@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Tycho Andersen <tycho@docker.com> Cc: Alexander Popov <alex.popov@linux.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-07 07:19:18 +08:00
freelist exploit methods.
mm: shuffle initial free memory to improve memory-side-cache utilization Patch series "mm: Randomize free memory", v10. This patch (of 3): Randomization of the page allocator improves the average utilization of a direct-mapped memory-side-cache. Memory side caching is a platform capability that Linux has been previously exposed to in HPC (high-performance computing) environments on specialty platforms. In that instance it was a smaller pool of high-bandwidth-memory relative to higher-capacity / lower-bandwidth DRAM. Now, this capability is going to be found on general purpose server platforms where DRAM is a cache in front of higher latency persistent memory [1]. Robert offered an explanation of the state of the art of Linux interactions with memory-side-caches [2], and I copy it here: It's been a problem in the HPC space: http://www.nersc.gov/research-and-development/knl-cache-mode-performance-coe/ A kernel module called zonesort is available to try to help: https://software.intel.com/en-us/articles/xeon-phi-software and this abandoned patch series proposed that for the kernel: https://lkml.kernel.org/r/20170823100205.17311-1-lukasz.daniluk@intel.com Dan's patch series doesn't attempt to ensure buffers won't conflict, but also reduces the chance that the buffers will. This will make performance more consistent, albeit slower than "optimal" (which is near impossible to attain in a general-purpose kernel). That's better than forcing users to deploy remedies like: "To eliminate this gradual degradation, we have added a Stream measurement to the Node Health Check that follows each job; nodes are rebooted whenever their measured memory bandwidth falls below 300 GB/s." A replacement for zonesort was merged upstream in commit cc9aec03e58f ("x86/numa_emulation: Introduce uniform split capability"). With this numa_emulation capability, memory can be split into cache sized ("near-memory" sized) numa nodes. A bind operation to such a node, and disabling workloads on other nodes, enables full cache performance. However, once the workload exceeds the cache size then cache conflicts are unavoidable. While HPC environments might be able to tolerate time-scheduling of cache sized workloads, for general purpose server platforms, the oversubscribed cache case will be the common case. The worst case scenario is that a server system owner benchmarks a workload at boot with an un-contended cache only to see that performance degrade over time, even below the average cache performance due to excessive conflicts. Randomization clips the peaks and fills in the valleys of cache utilization to yield steady average performance. Here are some performance impact details of the patches: 1/ An Intel internal synthetic memory bandwidth measurement tool, saw a 3X speedup in a contrived case that tries to force cache conflicts. The contrived cased used the numa_emulation capability to force an instance of the benchmark to be run in two of the near-memory sized numa nodes. If both instances were placed on the same emulated they would fit and cause zero conflicts. While on separate emulated nodes without randomization they underutilized the cache and conflicted unnecessarily due to the in-order allocation per node. 2/ A well known Java server application benchmark was run with a heap size that exceeded cache size by 3X. The cache conflict rate was 8% for the first run and degraded to 21% after page allocator aging. With randomization enabled the rate levelled out at 11%. 3/ A MongoDB workload did not observe measurable difference in cache-conflict rates, but the overall throughput dropped by 7% with randomization in one case. 4/ Mel Gorman ran his suite of performance workloads with randomization enabled on platforms without a memory-side-cache and saw a mix of some improvements and some losses [3]. While there is potentially significant improvement for applications that depend on low latency access across a wide working-set, the performance may be negligible to negative for other workloads. For this reason the shuffle capability defaults to off unless a direct-mapped memory-side-cache is detected. Even then, the page_alloc.shuffle=0 parameter can be specified to disable the randomization on those systems. Outside of memory-side-cache utilization concerns there is potentially security benefit from randomization. Some data exfiltration and return-oriented-programming attacks rely on the ability to infer the location of sensitive data objects. The kernel page allocator, especially early in system boot, has predictable first-in-first out behavior for physical pages. Pages are freed in physical address order when first onlined. Quoting Kees: "While we already have a base-address randomization (CONFIG_RANDOMIZE_MEMORY), attacks against the same hardware and memory layouts would certainly be using the predictability of allocation ordering (i.e. for attacks where the base address isn't important: only the relative positions between allocated memory). This is common in lots of heap-style attacks. They try to gain control over ordering by spraying allocations, etc. I'd really like to see this because it gives us something similar to CONFIG_SLAB_FREELIST_RANDOM but for the page allocator." While SLAB_FREELIST_RANDOM reduces the predictability of some local slab caches it leaves vast bulk of memory to be predictably in order allocated. However, it should be noted, the concrete security benefits are hard to quantify, and no known CVE is mitigated by this randomization. Introduce shuffle_free_memory(), and its helper shuffle_zone(), to perform a Fisher-Yates shuffle of the page allocator 'free_area' lists when they are initially populated with free memory at boot and at hotplug time. Do this based on either the presence of a page_alloc.shuffle=Y command line parameter, or autodetection of a memory-side-cache (to be added in a follow-on patch). The shuffling is done in terms of CONFIG_SHUFFLE_PAGE_ORDER sized free pages where the default CONFIG_SHUFFLE_PAGE_ORDER is MAX_ORDER-1 i.e. 10, 4MB this trades off randomization granularity for time spent shuffling. MAX_ORDER-1 was chosen to be minimally invasive to the page allocator while still showing memory-side cache behavior improvements, and the expectation that the security implications of finer granularity randomization is mitigated by CONFIG_SLAB_FREELIST_RANDOM. The performance impact of the shuffling appears to be in the noise compared to other memory initialization work. This initial randomization can be undone over time so a follow-on patch is introduced to inject entropy on page free decisions. It is reasonable to ask if the page free entropy is sufficient, but it is not enough due to the in-order initial freeing of pages. At the start of that process putting page1 in front or behind page0 still keeps them close together, page2 is still near page1 and has a high chance of being adjacent. As more pages are added ordering diversity improves, but there is still high page locality for the low address pages and this leads to no significant impact to the cache conflict rate. [1]: https://itpeernetwork.intel.com/intel-optane-dc-persistent-memory-operating-modes/ [2]: https://lkml.kernel.org/r/AT5PR8401MB1169D656C8B5E121752FC0F8AB120@AT5PR8401MB1169.NAMPRD84.PROD.OUTLOOK.COM [3]: https://lkml.org/lkml/2018/10/12/309 [dan.j.williams@intel.com: fix shuffle enable] Link: http://lkml.kernel.org/r/154943713038.3858443.4125180191382062871.stgit@dwillia2-desk3.amr.corp.intel.com [cai@lca.pw: fix SHUFFLE_PAGE_ALLOCATOR help texts] Link: http://lkml.kernel.org/r/20190425201300.75650-1-cai@lca.pw Link: http://lkml.kernel.org/r/154899811738.3165233.12325692939590944259.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Qian Cai <cai@lca.pw> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Robert Elliott <elliott@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-15 06:41:28 +08:00
config SHUFFLE_PAGE_ALLOCATOR
bool "Page allocator randomization"
default SLAB_FREELIST_RANDOM && ACPI_NUMA
help
Randomization of the page allocator improves the average
utilization of a direct-mapped memory-side-cache. See section
5.2.27 Heterogeneous Memory Attribute Table (HMAT) in the ACPI
6.2a specification for an example of how a platform advertises
the presence of a memory-side-cache. There are also incidental
security benefits as it reduces the predictability of page
allocations to compliment SLAB_FREELIST_RANDOM, but the
default granularity of shuffling on the "MAX_ORDER - 1" i.e,
10th order of pages is selected based on cache utilization
benefits on x86.
While the randomization improves cache utilization it may
negatively impact workloads on platforms without a cache. For
this reason, by default, the randomization is enabled only
after runtime detection of a direct-mapped memory-side-cache.
Otherwise, the randomization may be force enabled with the
'page_alloc.shuffle' kernel command line parameter.
Say Y if unsure.
slub: Make cpu partial slab support configurable CPU partial support can introduce level of indeterminism that is not wanted in certain context (like a realtime kernel). Make it configurable. This patch is based on Christoph Lameter's "slub: Make cpu partial slab support configurable V2". Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2013-06-19 13:05:52 +08:00
config SLUB_CPU_PARTIAL
default y
slub: don't use cpu partial pages on UP cpu partial pages are used to avoid contention which does not exist in the UP case. So let SLUB_CPU_PARTIAL depend on SMP. Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2013-07-17 22:54:59 +08:00
depends on SLUB && SMP
slub: Make cpu partial slab support configurable CPU partial support can introduce level of indeterminism that is not wanted in certain context (like a realtime kernel). Make it configurable. This patch is based on Christoph Lameter's "slub: Make cpu partial slab support configurable V2". Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2013-06-19 13:05:52 +08:00
bool "SLUB per cpu partial cache"
help
init/Kconfig: fix neighboring typos This fixes a couple typos I noticed in the slab Kconfig: sacrifies -> sacrifices accellerate -> accelerate Seeing as no other instances of these typos are found elsewhere in the kernel and that I originally added one of the two, I can only assume working on slab must have caused damage to the spelling centers of my brain. Link: http://lkml.kernel.org/r/201905292203.CD000546EB@keescook Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-17 07:27:57 +08:00
Per cpu partial caches accelerate objects allocation and freeing
slub: Make cpu partial slab support configurable CPU partial support can introduce level of indeterminism that is not wanted in certain context (like a realtime kernel). Make it configurable. This patch is based on Christoph Lameter's "slub: Make cpu partial slab support configurable V2". Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2013-06-19 13:05:52 +08:00
that is local to a processor at the price of more indeterminism
in the latency of the free. On overflow these caches will be cleared
which requires the taking of locks that may cause latency spikes.
Typically one would choose no for a realtime system.
nommu: fix malloc performance by adding uninitialized flag The NOMMU code currently clears all anonymous mmapped memory. While this is what we want in the default case, all memory allocation from userspace under NOMMU has to go through this interface, including malloc() which is allowed to return uninitialized memory. This can easily be a significant performance penalty. So for constrained embedded systems were security is irrelevant, allow people to avoid clearing memory unnecessarily. This also alters the ELF-FDPIC binfmt such that it obtains uninitialised memory for the brk and stack region. Signed-off-by: Jie Zhang <jie.zhang@analog.com> Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 10:00:02 +08:00
config MMAP_ALLOW_UNINITIALIZED
bool "Allow mmapped anonymous memory to be uninitialized"
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-21 06:44:16 +08:00
depends on EXPERT && !MMU
nommu: fix malloc performance by adding uninitialized flag The NOMMU code currently clears all anonymous mmapped memory. While this is what we want in the default case, all memory allocation from userspace under NOMMU has to go through this interface, including malloc() which is allowed to return uninitialized memory. This can easily be a significant performance penalty. So for constrained embedded systems were security is irrelevant, allow people to avoid clearing memory unnecessarily. This also alters the ELF-FDPIC binfmt such that it obtains uninitialised memory for the brk and stack region. Signed-off-by: Jie Zhang <jie.zhang@analog.com> Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 10:00:02 +08:00
default n
help
Normally, and according to the Linux spec, anonymous memory obtained
init/Kconfig: fix its typos Correct typos of "it's" to "its. Link: http://lkml.kernel.org/r/0ac627b6-5527-55f4-0489-1631aa34fc11@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 12:58:34 +08:00
from mmap() has its contents cleared before it is passed to
nommu: fix malloc performance by adding uninitialized flag The NOMMU code currently clears all anonymous mmapped memory. While this is what we want in the default case, all memory allocation from userspace under NOMMU has to go through this interface, including malloc() which is allowed to return uninitialized memory. This can easily be a significant performance penalty. So for constrained embedded systems were security is irrelevant, allow people to avoid clearing memory unnecessarily. This also alters the ELF-FDPIC binfmt such that it obtains uninitialised memory for the brk and stack region. Signed-off-by: Jie Zhang <jie.zhang@analog.com> Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 10:00:02 +08:00
userspace. Enabling this config option allows you to request that
mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
providing a huge performance boost. If this option is not enabled,
then the flag will be ignored.
This is taken advantage of by uClibc's malloc(), and also by
ELF-FDPIC binfmt's brk and stack allocator.
Because of the obvious security issues, this option should only be
enabled on embedded devices where you control what is run in
userspace. Since that isn't generally a problem on no-MMU systems,
it is normally safe to say Y here.
See Documentation/nommu-mmap.txt for more information.
MODSIGN: Extract the blob PKCS#7 signature verifier from module signing Extract the function that drives the PKCS#7 signature verification given a data blob and a PKCS#7 blob out from the module signing code and lump it with the system keyring code as it's generic. This makes it independent of module config options and opens it to use by the firmware loader. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ming Lei <ming.lei@canonical.com> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Kyle McMartin <kyle@kernel.org>
2015-07-21 04:16:28 +08:00
config SYSTEM_DATA_VERIFICATION
def_bool n
select SYSTEM_TRUSTED_KEYRING
select KEYS
select CRYPTO
akcipher: Move the RSA DER encoding check to the crypto layer Move the RSA EMSA-PKCS1-v1_5 encoding from the asymmetric-key public_key subtype to the rsa crypto module's pkcs1pad template. This means that the public_key subtype no longer has any dependencies on public key type. To make this work, the following changes have been made: (1) The rsa pkcs1pad template is now used for RSA keys. This strips off the padding and returns just the message hash. (2) In a previous patch, the pkcs1pad template gained an optional second parameter that, if given, specifies the hash used. We now give this, and pkcs1pad checks the encoded message E(M) for the EMSA-PKCS1-v1_5 encoding and verifies that the correct digest OID is present. (3) The crypto driver in crypto/asymmetric_keys/rsa.c is now reduced to something that doesn't care about what the encryption actually does and and has been merged into public_key.c. (4) CONFIG_PUBLIC_KEY_ALGO_RSA is gone. Module signing must set CONFIG_CRYPTO_RSA=y instead. Thoughts: (*) Should the encoding style (eg. raw, EMSA-PKCS1-v1_5) also be passed to the padding template? Should there be multiple padding templates registered that share most of the code? Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-04 05:49:27 +08:00
select CRYPTO_RSA
MODSIGN: Extract the blob PKCS#7 signature verifier from module signing Extract the function that drives the PKCS#7 signature verification given a data blob and a PKCS#7 blob out from the module signing code and lump it with the system keyring code as it's generic. This makes it independent of module config options and opens it to use by the firmware loader. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ming Lei <ming.lei@canonical.com> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Kyle McMartin <kyle@kernel.org>
2015-07-21 04:16:28 +08:00
select ASYMMETRIC_KEY_TYPE
select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
select ASN1
select OID_REGISTRY
select X509_CERTIFICATE_PARSER
select PKCS7_MESSAGE_PARSER
init/Kconfig: move the trusted keyring config option to general setup The SYSTEM_TRUSTED_KEYRING config option is not in any menu, causing it to show up in the toplevel of the kernel configuration. Fix this by moving it under the General Setup menu. Signed-off-by: Peter Foley <pefoley2@pefoley.com> Cc: David Howells <dhowells@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-19 06:07:11 +08:00
help
MODSIGN: Extract the blob PKCS#7 signature verifier from module signing Extract the function that drives the PKCS#7 signature verification given a data blob and a PKCS#7 blob out from the module signing code and lump it with the system keyring code as it's generic. This makes it independent of module config options and opens it to use by the firmware loader. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ming Lei <ming.lei@canonical.com> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Kyle McMartin <kyle@kernel.org>
2015-07-21 04:16:28 +08:00
Provide PKCS#7 message verification using the contents of the system
trusted keyring to provide public keys. This then can be used for
module verification, kexec image verification and firmware blob
verification.
init/Kconfig: move the trusted keyring config option to general setup The SYSTEM_TRUSTED_KEYRING config option is not in any menu, causing it to show up in the toplevel of the kernel configuration. Fix this by moving it under the General Setup menu. Signed-off-by: Peter Foley <pefoley2@pefoley.com> Cc: David Howells <dhowells@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-19 06:07:11 +08:00
Move Kconfig.instrumentation to arch/Kconfig and init/Kconfig Move the instrumentation Kconfig to arch/Kconfig for architecture dependent options - oprofile - kprobes and init/Kconfig for architecture independent options - profiling - markers Remove the "Instrumentation Support" menu. Everything moves to "General setup". Delete the kernel/Kconfig.instrumentation file. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-02-03 04:10:36 +08:00
config PROFILING
oprofile: remove EXPERIMENTAL from the config option description OProfile is already used for a long time and no longer experimental. Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-02-26 22:01:23 +08:00
bool "Profiling support"
Move Kconfig.instrumentation to arch/Kconfig and init/Kconfig Move the instrumentation Kconfig to arch/Kconfig for architecture dependent options - oprofile - kprobes and init/Kconfig for architecture independent options - profiling - markers Remove the "Instrumentation Support" menu. Everything moves to "General setup". Delete the kernel/Kconfig.instrumentation file. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-02-03 04:10:36 +08:00
help
Say Y here to enable the extended profiling support mechanisms used
by profilers such as OProfile.
tracing: clean up tracepoints kconfig structure do not expose users to CONFIG_TRACEPOINTS - tracers can select it just fine. update ftrace to select CONFIG_TRACEPOINTS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-23 20:15:22 +08:00
#
# Place an empty function call at each tracepoint site. Can be
# dynamically changed for a probe function.
#
tracing: Kernel Tracepoints Implementation of kernel tracepoints. Inspired from the Linux Kernel Markers. Allows complete typing verification by declaring both tracing statement inline functions and probe registration/unregistration static inline functions within the same macro "DEFINE_TRACE". No format string is required. See the tracepoint Documentation and Samples patches for usage examples. Taken from the documentation patch : "A tracepoint placed in code provides a hook to call a function (probe) that you can provide at runtime. A tracepoint can be "on" (a probe is connected to it) or "off" (no probe is attached). When a tracepoint is "off" it has no effect, except for adding a tiny time penalty (checking a condition for a branch) and space penalty (adding a few bytes for the function call at the end of the instrumented function and adds a data structure in a separate section). When a tracepoint is "on", the function you provide is called each time the tracepoint is executed, in the execution context of the caller. When the function provided ends its execution, it returns to the caller (continuing from the tracepoint site). You can put tracepoints at important locations in the code. They are lightweight hooks that can pass an arbitrary number of parameters, which prototypes are described in a tracepoint declaration placed in a header file." Addition and removal of tracepoints is synchronized by RCU using the scheduler (and preempt_disable) as guarantees to find a quiescent state (this is really RCU "classic"). The update side uses rcu_barrier_sched() with call_rcu_sched() and the read/execute side uses "preempt_disable()/preempt_enable()". We make sure the previous array containing probes, which has been scheduled for deletion by the rcu callback, is indeed freed before we proceed to the next update. It therefore limits the rate of modification of a single tracepoint to one update per RCU period. The objective here is to permit fast batch add/removal of probes on _different_ tracepoints. Changelog : - Use #name ":" #proto as string to identify the tracepoint in the tracepoint table. This will make sure not type mismatch happens due to connexion of a probe with the wrong type to a tracepoint declared with the same name in a different header. - Add tracepoint_entry_free_old. - Change __TO_TRACE to get rid of the 'i' iterator. Masami Hiramatsu <mhiramat@redhat.com> : Tested on x86-64. Performance impact of a tracepoint : same as markers, except that it adds about 70 bytes of instructions in an unlikely branch of each instrumented function (the for loop, the stack setup and the function call). It currently adds a memory read, a test and a conditional branch at the instrumentation site (in the hot path). Immediate values will eventually change this into a load immediate, test and branch, which removes the memory read which will make the i-cache impact smaller (changing the memory read for a load immediate removes 3-4 bytes per site on x86_32 (depending on mov prefixes), or 7-8 bytes on x86_64, it also saves the d-cache hit). About the performance impact of tracepoints (which is comparable to markers), even without immediate values optimizations, tests done by Hideo Aoki on ia64 show no regression. His test case was using hackbench on a kernel where scheduler instrumentation (about 5 events in code scheduler code) was added. Quoting Hideo Aoki about Markers : I evaluated overhead of kernel marker using linux-2.6-sched-fixes git tree, which includes several markers for LTTng, using an ia64 server. While the immediate trace mark feature isn't implemented on ia64, there is no major performance regression. So, I think that we don't have any issues to propose merging marker point patches into Linus's tree from the viewpoint of performance impact. I prepared two kernels to evaluate. The first one was compiled without CONFIG_MARKERS. The second one was enabled CONFIG_MARKERS. I downloaded the original hackbench from the following URL: http://devresources.linux-foundation.org/craiger/hackbench/src/hackbench.c I ran hackbench 5 times in each condition and calculated the average and difference between the kernels. The parameter of hackbench: every 50 from 50 to 800 The number of CPUs of the server: 2, 4, and 8 Below is the results. As you can see, major performance regression wasn't found in any case. Even if number of processes increases, differences between marker-enabled kernel and marker- disabled kernel doesn't increase. Moreover, if number of CPUs increases, the differences doesn't increase either. Curiously, marker-enabled kernel is better than marker-disabled kernel in more than half cases, although I guess it comes from the difference of memory access pattern. * 2 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 4.811 | 4.872 | +0.061 | +1.27 | 100 | 9.854 | 10.309 | +0.454 | +4.61 | 150 | 15.602 | 15.040 | -0.562 | -3.6 | 200 | 20.489 | 20.380 | -0.109 | -0.53 | 250 | 25.798 | 25.652 | -0.146 | -0.56 | 300 | 31.260 | 30.797 | -0.463 | -1.48 | 350 | 36.121 | 35.770 | -0.351 | -0.97 | 400 | 42.288 | 42.102 | -0.186 | -0.44 | 450 | 47.778 | 47.253 | -0.526 | -1.1 | 500 | 51.953 | 52.278 | +0.325 | +0.63 | 550 | 58.401 | 57.700 | -0.701 | -1.2 | 600 | 63.334 | 63.222 | -0.112 | -0.18 | 650 | 68.816 | 68.511 | -0.306 | -0.44 | 700 | 74.667 | 74.088 | -0.579 | -0.78 | 750 | 78.612 | 79.582 | +0.970 | +1.23 | 800 | 85.431 | 85.263 | -0.168 | -0.2 | -------------------------------------------------------------- * 4 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 2.586 | 2.584 | -0.003 | -0.1 | 100 | 5.254 | 5.283 | +0.030 | +0.56 | 150 | 8.012 | 8.074 | +0.061 | +0.76 | 200 | 11.172 | 11.000 | -0.172 | -1.54 | 250 | 13.917 | 14.036 | +0.119 | +0.86 | 300 | 16.905 | 16.543 | -0.362 | -2.14 | 350 | 19.901 | 20.036 | +0.135 | +0.68 | 400 | 22.908 | 23.094 | +0.186 | +0.81 | 450 | 26.273 | 26.101 | -0.172 | -0.66 | 500 | 29.554 | 29.092 | -0.461 | -1.56 | 550 | 32.377 | 32.274 | -0.103 | -0.32 | 600 | 35.855 | 35.322 | -0.533 | -1.49 | 650 | 39.192 | 38.388 | -0.804 | -2.05 | 700 | 41.744 | 41.719 | -0.025 | -0.06 | 750 | 45.016 | 44.496 | -0.520 | -1.16 | 800 | 48.212 | 47.603 | -0.609 | -1.26 | -------------------------------------------------------------- * 8 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 2.094 | 2.072 | -0.022 | -1.07 | 100 | 4.162 | 4.273 | +0.111 | +2.66 | 150 | 6.485 | 6.540 | +0.055 | +0.84 | 200 | 8.556 | 8.478 | -0.078 | -0.91 | 250 | 10.458 | 10.258 | -0.200 | -1.91 | 300 | 12.425 | 12.750 | +0.325 | +2.62 | 350 | 14.807 | 14.839 | +0.032 | +0.22 | 400 | 16.801 | 16.959 | +0.158 | +0.94 | 450 | 19.478 | 19.009 | -0.470 | -2.41 | 500 | 21.296 | 21.504 | +0.208 | +0.98 | 550 | 23.842 | 23.979 | +0.137 | +0.57 | 600 | 26.309 | 26.111 | -0.198 | -0.75 | 650 | 28.705 | 28.446 | -0.259 | -0.9 | 700 | 31.233 | 31.394 | +0.161 | +0.52 | 750 | 34.064 | 33.720 | -0.344 | -1.01 | 800 | 36.320 | 36.114 | -0.206 | -0.57 | -------------------------------------------------------------- Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: 'Peter Zijlstra' <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-19 00:16:16 +08:00
config TRACEPOINTS
tracing: clean up tracepoints kconfig structure do not expose users to CONFIG_TRACEPOINTS - tracers can select it just fine. update ftrace to select CONFIG_TRACEPOINTS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-23 20:15:22 +08:00
bool
tracing: Kernel Tracepoints Implementation of kernel tracepoints. Inspired from the Linux Kernel Markers. Allows complete typing verification by declaring both tracing statement inline functions and probe registration/unregistration static inline functions within the same macro "DEFINE_TRACE". No format string is required. See the tracepoint Documentation and Samples patches for usage examples. Taken from the documentation patch : "A tracepoint placed in code provides a hook to call a function (probe) that you can provide at runtime. A tracepoint can be "on" (a probe is connected to it) or "off" (no probe is attached). When a tracepoint is "off" it has no effect, except for adding a tiny time penalty (checking a condition for a branch) and space penalty (adding a few bytes for the function call at the end of the instrumented function and adds a data structure in a separate section). When a tracepoint is "on", the function you provide is called each time the tracepoint is executed, in the execution context of the caller. When the function provided ends its execution, it returns to the caller (continuing from the tracepoint site). You can put tracepoints at important locations in the code. They are lightweight hooks that can pass an arbitrary number of parameters, which prototypes are described in a tracepoint declaration placed in a header file." Addition and removal of tracepoints is synchronized by RCU using the scheduler (and preempt_disable) as guarantees to find a quiescent state (this is really RCU "classic"). The update side uses rcu_barrier_sched() with call_rcu_sched() and the read/execute side uses "preempt_disable()/preempt_enable()". We make sure the previous array containing probes, which has been scheduled for deletion by the rcu callback, is indeed freed before we proceed to the next update. It therefore limits the rate of modification of a single tracepoint to one update per RCU period. The objective here is to permit fast batch add/removal of probes on _different_ tracepoints. Changelog : - Use #name ":" #proto as string to identify the tracepoint in the tracepoint table. This will make sure not type mismatch happens due to connexion of a probe with the wrong type to a tracepoint declared with the same name in a different header. - Add tracepoint_entry_free_old. - Change __TO_TRACE to get rid of the 'i' iterator. Masami Hiramatsu <mhiramat@redhat.com> : Tested on x86-64. Performance impact of a tracepoint : same as markers, except that it adds about 70 bytes of instructions in an unlikely branch of each instrumented function (the for loop, the stack setup and the function call). It currently adds a memory read, a test and a conditional branch at the instrumentation site (in the hot path). Immediate values will eventually change this into a load immediate, test and branch, which removes the memory read which will make the i-cache impact smaller (changing the memory read for a load immediate removes 3-4 bytes per site on x86_32 (depending on mov prefixes), or 7-8 bytes on x86_64, it also saves the d-cache hit). About the performance impact of tracepoints (which is comparable to markers), even without immediate values optimizations, tests done by Hideo Aoki on ia64 show no regression. His test case was using hackbench on a kernel where scheduler instrumentation (about 5 events in code scheduler code) was added. Quoting Hideo Aoki about Markers : I evaluated overhead of kernel marker using linux-2.6-sched-fixes git tree, which includes several markers for LTTng, using an ia64 server. While the immediate trace mark feature isn't implemented on ia64, there is no major performance regression. So, I think that we don't have any issues to propose merging marker point patches into Linus's tree from the viewpoint of performance impact. I prepared two kernels to evaluate. The first one was compiled without CONFIG_MARKERS. The second one was enabled CONFIG_MARKERS. I downloaded the original hackbench from the following URL: http://devresources.linux-foundation.org/craiger/hackbench/src/hackbench.c I ran hackbench 5 times in each condition and calculated the average and difference between the kernels. The parameter of hackbench: every 50 from 50 to 800 The number of CPUs of the server: 2, 4, and 8 Below is the results. As you can see, major performance regression wasn't found in any case. Even if number of processes increases, differences between marker-enabled kernel and marker- disabled kernel doesn't increase. Moreover, if number of CPUs increases, the differences doesn't increase either. Curiously, marker-enabled kernel is better than marker-disabled kernel in more than half cases, although I guess it comes from the difference of memory access pattern. * 2 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 4.811 | 4.872 | +0.061 | +1.27 | 100 | 9.854 | 10.309 | +0.454 | +4.61 | 150 | 15.602 | 15.040 | -0.562 | -3.6 | 200 | 20.489 | 20.380 | -0.109 | -0.53 | 250 | 25.798 | 25.652 | -0.146 | -0.56 | 300 | 31.260 | 30.797 | -0.463 | -1.48 | 350 | 36.121 | 35.770 | -0.351 | -0.97 | 400 | 42.288 | 42.102 | -0.186 | -0.44 | 450 | 47.778 | 47.253 | -0.526 | -1.1 | 500 | 51.953 | 52.278 | +0.325 | +0.63 | 550 | 58.401 | 57.700 | -0.701 | -1.2 | 600 | 63.334 | 63.222 | -0.112 | -0.18 | 650 | 68.816 | 68.511 | -0.306 | -0.44 | 700 | 74.667 | 74.088 | -0.579 | -0.78 | 750 | 78.612 | 79.582 | +0.970 | +1.23 | 800 | 85.431 | 85.263 | -0.168 | -0.2 | -------------------------------------------------------------- * 4 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 2.586 | 2.584 | -0.003 | -0.1 | 100 | 5.254 | 5.283 | +0.030 | +0.56 | 150 | 8.012 | 8.074 | +0.061 | +0.76 | 200 | 11.172 | 11.000 | -0.172 | -1.54 | 250 | 13.917 | 14.036 | +0.119 | +0.86 | 300 | 16.905 | 16.543 | -0.362 | -2.14 | 350 | 19.901 | 20.036 | +0.135 | +0.68 | 400 | 22.908 | 23.094 | +0.186 | +0.81 | 450 | 26.273 | 26.101 | -0.172 | -0.66 | 500 | 29.554 | 29.092 | -0.461 | -1.56 | 550 | 32.377 | 32.274 | -0.103 | -0.32 | 600 | 35.855 | 35.322 | -0.533 | -1.49 | 650 | 39.192 | 38.388 | -0.804 | -2.05 | 700 | 41.744 | 41.719 | -0.025 | -0.06 | 750 | 45.016 | 44.496 | -0.520 | -1.16 | 800 | 48.212 | 47.603 | -0.609 | -1.26 | -------------------------------------------------------------- * 8 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 2.094 | 2.072 | -0.022 | -1.07 | 100 | 4.162 | 4.273 | +0.111 | +2.66 | 150 | 6.485 | 6.540 | +0.055 | +0.84 | 200 | 8.556 | 8.478 | -0.078 | -0.91 | 250 | 10.458 | 10.258 | -0.200 | -1.91 | 300 | 12.425 | 12.750 | +0.325 | +2.62 | 350 | 14.807 | 14.839 | +0.032 | +0.22 | 400 | 16.801 | 16.959 | +0.158 | +0.94 | 450 | 19.478 | 19.009 | -0.470 | -2.41 | 500 | 21.296 | 21.504 | +0.208 | +0.98 | 550 | 23.842 | 23.979 | +0.137 | +0.57 | 600 | 26.309 | 26.111 | -0.198 | -0.75 | 650 | 28.705 | 28.446 | -0.259 | -0.9 | 700 | 31.233 | 31.394 | +0.161 | +0.52 | 750 | 34.064 | 33.720 | -0.344 | -1.01 | 800 | 36.320 | 36.114 | -0.206 | -0.57 | -------------------------------------------------------------- Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: 'Peter Zijlstra' <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-19 00:16:16 +08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
endmenu # General setup
kconfig: include common Kconfig files from top-level Kconfig Instead of duplicating the source statements in every architecture just do it once in the toplevel Kconfig file. Note that with this the inclusion of arch/$(SRCARCH/Kconfig moves out of the top-level Kconfig into arch/Kconfig so that don't violate ordering constraits while keeping a sensible menu structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-31 19:39:30 +08:00
source "arch/Kconfig"
[PATCH] Kconfig: move CONFIG_EMBEDDED options to submenu Fix two problems with the CONFIG_EMBEDDED submenu: (1) The menu was split in two by the rt_mutex patch, which moved half the items into the "General setup" menu. (2) CONFIG_SYSCTL and CONFIG_UID16 were added to the main menu instead of the submenu. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-17 03:15:53 +08:00
config RT_MUTEXES
kconfig: use bool instead of boolean for type definition attributes Support for keyword 'boolean' will be dropped later on. No functional change. Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com Signed-off-by: Christoph Jaeger <cj@linux.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-12-21 04:41:11 +08:00
bool
[PATCH] Kconfig: move CONFIG_EMBEDDED options to submenu Fix two problems with the CONFIG_EMBEDDED submenu: (1) The menu was split in two by the rt_mutex patch, which moved half the items into the "General setup" menu. (2) CONFIG_SYSCTL and CONFIG_UID16 were added to the main menu instead of the submenu. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-17 03:15:53 +08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config BASE_SMALL
int
default 0 if BASE_FULL
default 1 if !BASE_FULL
MODSIGN: Export module signature definitions IMA will use the module_signature format for append signatures, so export the relevant definitions and factor out the code which verifies that the appended signature trailer is valid. Also, create a CONFIG_MODULE_SIG_FORMAT option so that IMA can select it and be able to use mod_check_sig() without having to depend on either CONFIG_MODULE_SIG or CONFIG_MODULES. s390 duplicated the definition of struct module_signature so now they can use the new <linux/module_signature.h> header instead. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Acked-by: Jessica Yu <jeyu@kernel.org> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-05 02:57:34 +08:00
config MODULE_SIG_FORMAT
def_bool n
select SYSTEM_DATA_VERIFICATION
Use menuconfig objects II - module menu Change menuconfig objects from "menu, config" into "menuconfig" so that the user can disable the whole feature without entering its menu first. Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 14:39:29 +08:00
menuconfig MODULES
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
bool "Enable loadable module support"
modules: do not depend on kconfig to set 'modules' option to symbol MODULES Currently, the MODULES symbol is special-cased in different places in the kconfig language. For example, if no symbol is defined to enable tristates, then kconfig looks up for a symbol named 'MODULES', and forces the 'modules' option onto that symbol. This causes problems as such: - since MODULES is special-cased, reading the configuration with KCONFIG_ALLCONFIG set will forcibly set MODULES to be 'valid' (ie. it has a valid value), when no such value was previously set. So MODULES defaults to 'n' unless it is present in KCONFIG_ALLCONFIG - other third-party projects may decide that 'MODULES' plays a different role for them This has been exposed by cset #cfa98f2e: kconfig: do not override symbols already set and reported by Stephen in: http://marc.info/?l=linux-next&m=137592137915234&w=2 As suggested by Sam, we explicitly define the MODULES symbol to be the tristate-enabler. This will allow us to drop special-casing of MODULES in the kconfig language, later. (Note: this patch is not a fix to Stephen's issue, just a first step). Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: yann.morin.1998@free.fr Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Kevin Hilman <khilman@linaro.org> Cc: sedat.dilek@gmail.com Cc: Theodore Ts'o <tytso@mit.edu>
2013-08-11 22:07:50 +08:00
option modules
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
help
Kernel modules are small pieces of compiled code which can
be inserted in the running kernel, rather than being
permanently built into the kernel. You use the "modprobe"
tool to add (and sometimes remove) them. If you say Y here,
many parts of the kernel can be built as modules (by
answering M instead of Y where indicated): this is most
useful for infrequently used options which are not required
for booting. For more information, see the man pages for
modprobe, lsmod, modinfo, insmod and rmmod.
If you say Y here, you will need to run "make
modules_install" to put the modules under /lib/modules/
where modprobe can find them (you may need to be root to do
this).
If unsure, say Y.
Kconfig: Extend "menuconfig" for modules to simplify Kconfig file Given that the init/Kconfig file uses a "menuconfig" directive for modules already, might as well wrap all the submenu entries in an "if" to toss all those dependencies. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-08-05 01:31:32 +08:00
if MODULES
Make forced module loading optional The kernel module loader used to be much too happy to allow loading of modules for the wrong kernel version by default. For example, if you had MODVERSIONS enabled, but tried to load a module with no version info, it would happily load it and taint the kernel - whether it was likely to actually work or not! Generally, such forced module loading should be considered a really really bad idea, so make it conditional on a new config option (MODULE_FORCE_LOAD), and make it default to off. If somebody really wants to force module loads, that's their problem, but we should not encourage it. Especially as it happened to me by mistake (ie regular unversioned Fedora modules getting loaded) causing lots of strange behavior. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-05 08:04:16 +08:00
config MODULE_FORCE_LOAD
bool "Forced module loading"
default n
help
module: don't ignore vermagic string if module doesn't have modversions Linus found a logic bug: we ignore the version number in a module's vermagic string if we have CONFIG_MODVERSIONS set, but modversions also lets through a module with no __versions section for modprobe --force (with tainting, but still). We should only ignore the start of the vermagic string if the module actually *has* crcs to check. Rather than (say) having an entertaining hissy fit and creating a config option to work around the buggy code. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-09 14:25:28 +08:00
Allow loading of modules without version information (ie. modprobe
--force). Forced module loading sets the 'F' (forced) taint flag and
is usually a really bad idea.
Make forced module loading optional The kernel module loader used to be much too happy to allow loading of modules for the wrong kernel version by default. For example, if you had MODVERSIONS enabled, but tried to load a module with no version info, it would happily load it and taint the kernel - whether it was likely to actually work or not! Generally, such forced module loading should be considered a really really bad idea, so make it conditional on a new config option (MODULE_FORCE_LOAD), and make it default to off. If somebody really wants to force module loads, that's their problem, but we should not encourage it. Especially as it happened to me by mistake (ie regular unversioned Fedora modules getting loaded) causing lots of strange behavior. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-05 08:04:16 +08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config MODULE_UNLOAD
bool "Module unloading"
help
Without this option you will not be able to unload any
modules (note that some modules may not be unloadable
Shrink struct module: CONFIG_UNUSED_SYMBOLS ifdefs module.c and module.h conatains code for finding exported symbols which are declared with EXPORT_UNUSED_SYMBOL, and this code is compiled in even if CONFIG_UNUSED_SYMBOLS is not set and thus there can be no EXPORT_UNUSED_SYMBOLs in modules anyway (because EXPORT_UNUSED_SYMBOL(x) are compiled out to nothing then). This patch adds required #ifdefs. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-23 08:24:26 +08:00
anyway), which makes your kernel smaller, faster
and simpler. If unsure, say Y.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config MODULE_FORCE_UNLOAD
bool "Forced module unloading"
init: remove depends on CONFIG_EXPERIMENTAL The CONFIG_EXPERIMENTAL config item has not carried much meaning for a while now and is almost always enabled by default. As agreed during the Linux kernel summit, remove it from any "depends on" lines in Kconfigs. CC: "Eric W. Biederman" <ebiederm@xmission.com> CC: Serge Hallyn <serge.hallyn@canonical.com> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2012-10-03 02:19:29 +08:00
depends on MODULE_UNLOAD
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
help
This option allows you to force a module to unload, even if the
kernel believes it is unsafe: the kernel will remove the module
without waiting for anyone to stop using it (using the -f option to
rmmod). This is mainly for kernel developers and desperate users.
If unsure, say N.
config MODVERSIONS
kbuild: remove EXPERIMENTAL tag from Module versioning Module versioning support has been stable for a loong time so let's get rid of the EXPERIMENTAL tag. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-12-27 06:04:02 +08:00
bool "Module versioning support"
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
help
Usually, you have to use modules compiled with your kernel.
Saying Y here makes it sometimes possible to use modules
compiled for different kernels, by adding enough information
to the modules to (hopefully) spot any changes which would
make them incompatible with the kernel you are running. If
unsure, say N.
kbuild: add CONFIG_ASM_MODVERSIONS Add CONFIG_ASM_MODVERSIONS. This allows to remove one if-conditional nesting in scripts/Makefile.build. scripts/Makefile.build is run every time Kbuild descends into a sub-directory. So, I want to avoid $(wildcard ...) evaluation where possible although computing $(wildcard ...) is so cheap that it may not make measurable performance difference. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2019-08-19 13:54:20 +08:00
config ASM_MODVERSIONS
bool
default HAVE_ASM_MODVERSIONS && MODVERSIONS
help
This enables module versioning for exported symbols also from
assembly. This can be enabled only when the target architecture
supports it.
kbuild: modversions: add infrastructure for emitting relative CRCs This add the kbuild infrastructure that will allow architectures to emit vmlinux symbol CRCs as 32-bit offsets to another location in the kernel where the actual value is stored. This works around problems with CRCs being mistaken for relocatable symbols on kernels that self relocate at runtime (i.e., powerpc with CONFIG_RELOCATABLE=y) For the kbuild side of things, this comes down to the following: - introducing a Kconfig symbol MODULE_REL_CRCS - adding a -R switch to genksyms to instruct it to emit the CRC symbols as references into the .rodata section - making modpost distinguish such references from absolute CRC symbols by the section index (SHN_ABS) - making kallsyms disregard non-absolute symbols with a __crc_ prefix Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-03 17:54:05 +08:00
config MODULE_REL_CRCS
bool
depends on MODVERSIONS
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
config MODULE_SRCVERSION_ALL
bool "Source checksum for all modules"
help
Modules which contain a MODULE_VERSION get an extra "srcversion"
field inserted into their modinfo section, which contains a
sum of the source files which made it. This helps maintainers
see exactly which source was used to build a module (since
others sometimes change the module source without updating
the version). With this option, such a "srcversion" field
will be created for all modules. If unsure, say N.
module: signature checking hook We do a very simple search for a particular string appended to the module (which is cache-hot and about to be SHA'd anyway). There's both a config option and a boot parameter which control whether we accept or fail with unsigned modules and modules that are signed with an unknown key. If module signing is enabled, the kernel will be tainted if a module is loaded that is unsigned or has a signature for which we don't have the key. (Useful feedback and tweaks by David Howells <dhowells@redhat.com>) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-26 17:09:40 +08:00
config MODULE_SIG
bool "Module signature verification"
MODSIGN: Export module signature definitions IMA will use the module_signature format for append signatures, so export the relevant definitions and factor out the code which verifies that the appended signature trailer is valid. Also, create a CONFIG_MODULE_SIG_FORMAT option so that IMA can select it and be able to use mod_check_sig() without having to depend on either CONFIG_MODULE_SIG or CONFIG_MODULES. s390 duplicated the definition of struct module_signature so now they can use the new <linux/module_signature.h> header instead. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Acked-by: Jessica Yu <jeyu@kernel.org> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-05 02:57:34 +08:00
select MODULE_SIG_FORMAT
module: signature checking hook We do a very simple search for a particular string appended to the module (which is cache-hot and about to be SHA'd anyway). There's both a config option and a boot parameter which control whether we accept or fail with unsigned modules and modules that are signed with an unknown key. If module signing is enabled, the kernel will be tainted if a module is loaded that is unsigned or has a signature for which we don't have the key. (Useful feedback and tweaks by David Howells <dhowells@redhat.com>) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-26 17:09:40 +08:00
help
Check modules for valid signatures upon load: the signature
is simply appended to the module. For more information see
init/Kconfig: Fix module signing document location This was moved in commit 94e980cc45f2 ("Documentation/module-signing.txt: convert to ReST markup") and was missed by commit 8c27ceff3604 ("docs: fix locations of several documents that got moved"). Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-09-10 17:48:29 +08:00
<file:Documentation/admin-guide/module-signing.rst>.
module: signature checking hook We do a very simple search for a particular string appended to the module (which is cache-hot and about to be SHA'd anyway). There's both a config option and a boot parameter which control whether we accept or fail with unsigned modules and modules that are signed with an unknown key. If module signing is enabled, the kernel will be tainted if a module is loaded that is unsigned or has a signature for which we don't have the key. (Useful feedback and tweaks by David Howells <dhowells@redhat.com>) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-26 17:09:40 +08:00
sign-file: Document dependency on OpenSSL devel libraries The revised sign-file program is no longer a script that wraps the openssl program, but now rather a program that makes use of OpenSSL's crypto library. This means that to build the sign-file program, the kernel build process now has a dependency on the OpenSSL development packages in addition to OpenSSL itself. Document this in Kconfig and in module-signing.txt. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
2015-08-11 19:38:54 +08:00
Note that this option adds the OpenSSL development packages as a
kernel build dependency so that the signing tool can use its crypto
library.
lockdown: Enforce module signatures if the kernel is locked down If the kernel is locked down, require that all modules have valid signatures that we can verify. I have adjusted the errors generated: (1) If there's no signature (ENODATA) or we can't check it (ENOPKG, ENOKEY), then: (a) If signatures are enforced then EKEYREJECTED is returned. (b) If there's no signature or we can't check it, but the kernel is locked down then EPERM is returned (this is then consistent with other lockdown cases). (2) If the signature is unparseable (EBADMSG, EINVAL), the signature fails the check (EKEYREJECTED) or a system error occurs (eg. ENOMEM), we return the error we got. Note that the X.509 code doesn't check for key expiry as the RTC might not be valid or might not have been transferred to the kernel's clock yet. [Modified by Matthew Garrett to remove the IMA integration. This will be replaced with integration with the IMA architecture policy patchset.] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Matthew Garrett <matthewgarrett@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Jessica Yu <jeyu@kernel.org> Signed-off-by: James Morris <jmorris@namei.org>
2019-08-20 08:17:40 +08:00
You should enable this option if you wish to use either
CONFIG_SECURITY_LOCKDOWN_LSM or lockdown functionality imposed via
another LSM - otherwise unsigned modules will be loadable regardless
of the lockdown policy.
MODSIGN: Provide Kconfig options Provide kernel configuration options for module signing. The following configuration options are added: CONFIG_MODULE_SIG_SHA1 CONFIG_MODULE_SIG_SHA224 CONFIG_MODULE_SIG_SHA256 CONFIG_MODULE_SIG_SHA384 CONFIG_MODULE_SIG_SHA512 These select the cryptographic hash used to digest the data prior to signing. Additionally, the crypto module selected will be built into the kernel as it won't be possible to load it as a module without incurring a circular dependency when the kernel tries to check its signature. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-26 17:09:50 +08:00
!!!WARNING!!! If you enable this option, you MUST make sure that the
module DOES NOT get stripped after being signed. This includes the
debuginfo strip done by some packagers (such as rpmbuild) and
inclusion into an initramfs that wants the module size reduced.
module: signature checking hook We do a very simple search for a particular string appended to the module (which is cache-hot and about to be SHA'd anyway). There's both a config option and a boot parameter which control whether we accept or fail with unsigned modules and modules that are signed with an unknown key. If module signing is enabled, the kernel will be tainted if a module is loaded that is unsigned or has a signature for which we don't have the key. (Useful feedback and tweaks by David Howells <dhowells@redhat.com>) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-26 17:09:40 +08:00
config MODULE_SIG_FORCE
bool "Require modules to be validly signed"
depends on MODULE_SIG
help
Reject unsigned modules or signed modules for which we don't have a
key. Without this, such modules will simply taint the kernel.
MODSIGN: Provide Kconfig options Provide kernel configuration options for module signing. The following configuration options are added: CONFIG_MODULE_SIG_SHA1 CONFIG_MODULE_SIG_SHA224 CONFIG_MODULE_SIG_SHA256 CONFIG_MODULE_SIG_SHA384 CONFIG_MODULE_SIG_SHA512 These select the cryptographic hash used to digest the data prior to signing. Additionally, the crypto module selected will be built into the kernel as it won't be possible to load it as a module without incurring a circular dependency when the kernel tries to check its signature. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-26 17:09:50 +08:00
MODSIGN: Add option to not sign modules during modules_install To allow the builder to sign only a subset of modules, or to sign the modules using a key that is not available on the build machine, add CONFIG_MODULE_SIG_ALL. If this option is unset, no modules will be signed during build. The default is 'y', to preserve the current behavior. Signed-off-by: Michal Marek <mmarek@suse.cz> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-25 11:11:31 +08:00
config MODULE_SIG_ALL
bool "Automatically sign all modules"
default y
depends on MODULE_SIG
help
Sign all modules during make modules_install. Without this option,
modules must be signed manually, using the scripts/sign-file tool.
comment "Do not forget to sign required modules with scripts/sign-file"
depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
MODSIGN: Provide Kconfig options Provide kernel configuration options for module signing. The following configuration options are added: CONFIG_MODULE_SIG_SHA1 CONFIG_MODULE_SIG_SHA224 CONFIG_MODULE_SIG_SHA256 CONFIG_MODULE_SIG_SHA384 CONFIG_MODULE_SIG_SHA512 These select the cryptographic hash used to digest the data prior to signing. Additionally, the crypto module selected will be built into the kernel as it won't be possible to load it as a module without incurring a circular dependency when the kernel tries to check its signature. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-26 17:09:50 +08:00
choice
prompt "Which hash algorithm should modules be signed with?"
depends on MODULE_SIG
help
This determines which sort of hashing algorithm will be used during
signature generation. This algorithm _must_ be built into the kernel
directly so that signature verification can take place. It is not
possible to load a signed module containing the algorithm to check
the signature on that module.
config MODULE_SIG_SHA1
bool "Sign modules with SHA-1"
select CRYPTO_SHA1
config MODULE_SIG_SHA224
bool "Sign modules with SHA-224"
select CRYPTO_SHA256
config MODULE_SIG_SHA256
bool "Sign modules with SHA-256"
select CRYPTO_SHA256
config MODULE_SIG_SHA384
bool "Sign modules with SHA-384"
select CRYPTO_SHA512
config MODULE_SIG_SHA512
bool "Sign modules with SHA-512"
select CRYPTO_SHA512
endchoice
MODSIGN: Simplify Makefile with a Kconfig helper Signed-off-by: Michal Marek <mmarek@suse.cz> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-25 11:11:00 +08:00
config MODULE_SIG_HASH
string
depends on MODULE_SIG
default "sha1" if MODULE_SIG_SHA1
default "sha224" if MODULE_SIG_SHA224
default "sha256" if MODULE_SIG_SHA256
default "sha384" if MODULE_SIG_SHA384
default "sha512" if MODULE_SIG_SHA512
kbuild: handle module compression while running 'make modules_install'. Since module-init-tools (gzip) and kmod (gzip and xz) support compressed modules, it could be useful to include a support for compressing modules right after having them installed. Doing this in kbuild instead of per distro can permit to make this kind of usage more generic. This patch add a Kconfig entry to "Enable loadable module support" menu and let you choose to compress using gzip (default) or xz. Both gzip and xz does not used any extra -[1-9] option since Andi Kleen and Rusty Russell prove no gain is made using them. gzip is called with -n argument to avoid storing original filename inside compressed file, that way we can save some more bytes. On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a total of 378MB (no strip, no sign, no compress), the following table shows observed disk space gain based on the allmodconfig .config : | time | +-------------+-----------------+ | manual .ko | make | size | percent | compression | modules_install | | gain +-------------+-----------------+------+-------- - | | 18.61s | 378M | GZIP | 3m16s | 3m37s | 102M | 73.41% XZ | 5m22s | 5m39s | 77M | 79.83% The gain for restricted environnement seems to be interesting while uncompress can be time consuming but happens only while loading a module, that is generally done only once. This is fully compatible with signed modules while the signed module is compressed. module-init-tools or kmod handles decompression and provide to other layer the uncompressed but signed payload. Reviewed-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Bertrand Jacquin <beber@meleeweb.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 19:01:56 +08:00
config MODULE_COMPRESS
bool "Compress modules on installation"
help
modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. Andreas turned this option on, only to find out Debian (and Ubuntu!) don't enable support in their kmod builds. Shorten the text, and suggest N at the bottom (at least for now). Reported-by: Andreas Mohr <andim2@users.sf.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-16 10:46:22 +08:00
Compresses kernel modules when 'make modules_install' is run; gzip or
xz depending on "Compression algorithm" below.
kbuild: handle module compression while running 'make modules_install'. Since module-init-tools (gzip) and kmod (gzip and xz) support compressed modules, it could be useful to include a support for compressing modules right after having them installed. Doing this in kbuild instead of per distro can permit to make this kind of usage more generic. This patch add a Kconfig entry to "Enable loadable module support" menu and let you choose to compress using gzip (default) or xz. Both gzip and xz does not used any extra -[1-9] option since Andi Kleen and Rusty Russell prove no gain is made using them. gzip is called with -n argument to avoid storing original filename inside compressed file, that way we can save some more bytes. On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a total of 378MB (no strip, no sign, no compress), the following table shows observed disk space gain based on the allmodconfig .config : | time | +-------------+-----------------+ | manual .ko | make | size | percent | compression | modules_install | | gain +-------------+-----------------+------+-------- - | | 18.61s | 378M | GZIP | 3m16s | 3m37s | 102M | 73.41% XZ | 5m22s | 5m39s | 77M | 79.83% The gain for restricted environnement seems to be interesting while uncompress can be time consuming but happens only while loading a module, that is generally done only once. This is fully compatible with signed modules while the signed module is compressed. module-init-tools or kmod handles decompression and provide to other layer the uncompressed but signed payload. Reviewed-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Bertrand Jacquin <beber@meleeweb.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 19:01:56 +08:00
modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. Andreas turned this option on, only to find out Debian (and Ubuntu!) don't enable support in their kmod builds. Shorten the text, and suggest N at the bottom (at least for now). Reported-by: Andreas Mohr <andim2@users.sf.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-16 10:46:22 +08:00
module-init-tools MAY support gzip, and kmod MAY support gzip and xz.
kbuild: handle module compression while running 'make modules_install'. Since module-init-tools (gzip) and kmod (gzip and xz) support compressed modules, it could be useful to include a support for compressing modules right after having them installed. Doing this in kbuild instead of per distro can permit to make this kind of usage more generic. This patch add a Kconfig entry to "Enable loadable module support" menu and let you choose to compress using gzip (default) or xz. Both gzip and xz does not used any extra -[1-9] option since Andi Kleen and Rusty Russell prove no gain is made using them. gzip is called with -n argument to avoid storing original filename inside compressed file, that way we can save some more bytes. On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a total of 378MB (no strip, no sign, no compress), the following table shows observed disk space gain based on the allmodconfig .config : | time | +-------------+-----------------+ | manual .ko | make | size | percent | compression | modules_install | | gain +-------------+-----------------+------+-------- - | | 18.61s | 378M | GZIP | 3m16s | 3m37s | 102M | 73.41% XZ | 5m22s | 5m39s | 77M | 79.83% The gain for restricted environnement seems to be interesting while uncompress can be time consuming but happens only while loading a module, that is generally done only once. This is fully compatible with signed modules while the signed module is compressed. module-init-tools or kmod handles decompression and provide to other layer the uncompressed but signed payload. Reviewed-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Bertrand Jacquin <beber@meleeweb.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 19:01:56 +08:00
modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. Andreas turned this option on, only to find out Debian (and Ubuntu!) don't enable support in their kmod builds. Shorten the text, and suggest N at the bottom (at least for now). Reported-by: Andreas Mohr <andim2@users.sf.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-16 10:46:22 +08:00
Out-of-tree kernel modules installed using Kbuild will also be
compressed upon installation.
kbuild: handle module compression while running 'make modules_install'. Since module-init-tools (gzip) and kmod (gzip and xz) support compressed modules, it could be useful to include a support for compressing modules right after having them installed. Doing this in kbuild instead of per distro can permit to make this kind of usage more generic. This patch add a Kconfig entry to "Enable loadable module support" menu and let you choose to compress using gzip (default) or xz. Both gzip and xz does not used any extra -[1-9] option since Andi Kleen and Rusty Russell prove no gain is made using them. gzip is called with -n argument to avoid storing original filename inside compressed file, that way we can save some more bytes. On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a total of 378MB (no strip, no sign, no compress), the following table shows observed disk space gain based on the allmodconfig .config : | time | +-------------+-----------------+ | manual .ko | make | size | percent | compression | modules_install | | gain +-------------+-----------------+------+-------- - | | 18.61s | 378M | GZIP | 3m16s | 3m37s | 102M | 73.41% XZ | 5m22s | 5m39s | 77M | 79.83% The gain for restricted environnement seems to be interesting while uncompress can be time consuming but happens only while loading a module, that is generally done only once. This is fully compatible with signed modules while the signed module is compressed. module-init-tools or kmod handles decompression and provide to other layer the uncompressed but signed payload. Reviewed-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Bertrand Jacquin <beber@meleeweb.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 19:01:56 +08:00
modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. Andreas turned this option on, only to find out Debian (and Ubuntu!) don't enable support in their kmod builds. Shorten the text, and suggest N at the bottom (at least for now). Reported-by: Andreas Mohr <andim2@users.sf.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-16 10:46:22 +08:00
Note: for modules inside an initrd or initramfs, it's more efficient
to compress the whole initrd or initramfs instead.
kbuild: handle module compression while running 'make modules_install'. Since module-init-tools (gzip) and kmod (gzip and xz) support compressed modules, it could be useful to include a support for compressing modules right after having them installed. Doing this in kbuild instead of per distro can permit to make this kind of usage more generic. This patch add a Kconfig entry to "Enable loadable module support" menu and let you choose to compress using gzip (default) or xz. Both gzip and xz does not used any extra -[1-9] option since Andi Kleen and Rusty Russell prove no gain is made using them. gzip is called with -n argument to avoid storing original filename inside compressed file, that way we can save some more bytes. On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a total of 378MB (no strip, no sign, no compress), the following table shows observed disk space gain based on the allmodconfig .config : | time | +-------------+-----------------+ | manual .ko | make | size | percent | compression | modules_install | | gain +-------------+-----------------+------+-------- - | | 18.61s | 378M | GZIP | 3m16s | 3m37s | 102M | 73.41% XZ | 5m22s | 5m39s | 77M | 79.83% The gain for restricted environnement seems to be interesting while uncompress can be time consuming but happens only while loading a module, that is generally done only once. This is fully compatible with signed modules while the signed module is compressed. module-init-tools or kmod handles decompression and provide to other layer the uncompressed but signed payload. Reviewed-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Bertrand Jacquin <beber@meleeweb.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 19:01:56 +08:00
modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. Andreas turned this option on, only to find out Debian (and Ubuntu!) don't enable support in their kmod builds. Shorten the text, and suggest N at the bottom (at least for now). Reported-by: Andreas Mohr <andim2@users.sf.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-16 10:46:22 +08:00
Note: This is fully compatible with signed modules.
If in doubt, say N.
kbuild: handle module compression while running 'make modules_install'. Since module-init-tools (gzip) and kmod (gzip and xz) support compressed modules, it could be useful to include a support for compressing modules right after having them installed. Doing this in kbuild instead of per distro can permit to make this kind of usage more generic. This patch add a Kconfig entry to "Enable loadable module support" menu and let you choose to compress using gzip (default) or xz. Both gzip and xz does not used any extra -[1-9] option since Andi Kleen and Rusty Russell prove no gain is made using them. gzip is called with -n argument to avoid storing original filename inside compressed file, that way we can save some more bytes. On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a total of 378MB (no strip, no sign, no compress), the following table shows observed disk space gain based on the allmodconfig .config : | time | +-------------+-----------------+ | manual .ko | make | size | percent | compression | modules_install | | gain +-------------+-----------------+------+-------- - | | 18.61s | 378M | GZIP | 3m16s | 3m37s | 102M | 73.41% XZ | 5m22s | 5m39s | 77M | 79.83% The gain for restricted environnement seems to be interesting while uncompress can be time consuming but happens only while loading a module, that is generally done only once. This is fully compatible with signed modules while the signed module is compressed. module-init-tools or kmod handles decompression and provide to other layer the uncompressed but signed payload. Reviewed-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Bertrand Jacquin <beber@meleeweb.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 19:01:56 +08:00
choice
prompt "Compression algorithm"
depends on MODULE_COMPRESS
default MODULE_COMPRESS_GZIP
help
This determines which sort of compression will be used during
'make modules_install'.
GZIP (default) and XZ are supported.
config MODULE_COMPRESS_GZIP
bool "GZIP"
config MODULE_COMPRESS_XZ
bool "XZ"
endchoice
module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS If MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS is enabled (default=n), the requirement for modules to import all namespaces that are used by the module is relaxed. Enabling this option effectively allows (invalid) modules to be loaded while only a warning is emitted. Disabling this option keeps the enforcement at module loading time and loading is denied if the module's imports are not satisfactory. Reviewed-by: Martijn Coenen <maco@android.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Matthias Maennich <maennich@google.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-09-06 18:32:29 +08:00
config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
bool "Allow loading of modules with missing namespace imports"
help
Symbols exported with EXPORT_SYMBOL_NS*() are considered exported in
a namespace. A module that makes use of a symbol exported with such a
namespace is required to import the namespace via MODULE_IMPORT_NS().
There is no technical reason to enforce correct namespace imports,
but it creates consistency between symbols defining namespaces and
users importing namespaces they make use of. This option relaxes this
requirement and lifts the enforcement when loading a module.
If unsure, say N.
module: move CONFIG_UNUSED_SYMBOLS to the sub-menu of MODULES When CONFIG_MODULES is disabled, CONFIG_UNUSED_SYMBOLS is pointless, thus it should be invisible. Instead of adding "depends on MODULES", I moved it to the sub-menu "Enable loadable module support", which is a better fit. I put it close to TRIM_UNUSED_KSYMS because it depends on !UNUSED_SYMBOLS. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-09-09 19:04:08 +08:00
config UNUSED_SYMBOLS
bool "Enable unused/obsolete exported symbols"
default y if X86
help
Unused but exported symbols make the kernel needlessly bigger. For
that reason most of these unused exports will soon be removed. This
option is provided temporarily to provide a transition period in case
some external kernel module needs one of these symbols anyway. If you
encounter such a case in your module, consider if you are actually
using the right API. (rationale: since nobody in the kernel is using
this in a module, there is a pretty good chance it's actually the
wrong interface to use). If you really need the symbol, please send a
mail to the linux kernel mailing list mentioning the symbol and why
you really need it, and what the merge plan to the mainline kernel for
your module is.
kconfig option for TRIM_UNUSED_KSYMS The config option to enable it all. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2016-01-27 10:51:05 +08:00
config TRIM_UNUSED_KSYMS
bool "Trim unused exported kernel symbols"
module: remove redundant 'depends on MODULES' These are located in the 'if MODULES' ... 'endif' block. Remove the redundant dependencies. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-09-09 19:04:07 +08:00
depends on !UNUSED_SYMBOLS
kconfig option for TRIM_UNUSED_KSYMS The config option to enable it all. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2016-01-27 10:51:05 +08:00
help
The kernel and some modules make many symbols available for
other modules to use via EXPORT_SYMBOL() and variants. Depending
on the set of modules being selected in your kernel configuration,
many of those exported symbols might never be used.
This option allows for unused exported symbols to be dropped from
the build. In turn, this provides the compiler more opportunities
(especially when using LTO) for optimizing the code and reducing
binary size. This might have some security advantages as well.
init/Kconfig: add clarification for out-of-tree modules It doesn't trim just symbols that are totally unused in-tree - it trims the symbols unused by any in-tree modules actually built. If you've done a 'make localmodconfig' and only build a hundred or so modules, it's pretty likely that your out-of-tree module will come up lacking something... Hopefully this will save the next guy from a Homer Simpson "D'oh!" moment. Link: http://lkml.kernel.org/r/10177.1469787292@turing-police.cc.vt.edu Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: Michal Marek <mmarek@suse.cz> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-03 05:07:27 +08:00
If unsure, or if you need to build out-of-tree modules, say N.
kconfig option for TRIM_UNUSED_KSYMS The config option to enable it all. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2016-01-27 10:51:05 +08:00
kbuild: allow symbol whitelisting with TRIM_UNUSED_KSYMS CONFIG_TRIM_UNUSED_KSYMS currently removes all unused exported symbols from ksymtab. This works really well when using in-tree drivers, but cannot be used in its current form if some of them are out-of-tree. Indeed, even if the list of symbols required by out-of-tree drivers is known at compile time, the only solution today to guarantee these don't get trimmed is to set CONFIG_TRIM_UNUSED_KSYMS=n. This not only wastes space, but also makes it difficult to control the ABI usable by vendor modules in distribution kernels such as Android. Being able to control the kernel ABI surface is particularly useful to ship a unique Generic Kernel Image (GKI) for all vendors, which is a first step in the direction of getting all vendors to contribute their code upstream. As such, attempt to improve the situation by enabling users to specify a symbol 'whitelist' at compile time. Any symbol specified in this whitelist will be kept exported when CONFIG_TRIM_UNUSED_KSYMS is set, even if it has no in-tree user. The whitelist is defined as a simple text file, listing symbols, one per line. Acked-by: Jessica Yu <jeyu@kernel.org> Acked-by: Nicolas Pitre <nico@fluxnic.net> Tested-by: Matthias Maennich <maennich@google.com> Reviewed-by: Matthias Maennich <maennich@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-29 01:20:13 +08:00
config UNUSED_KSYMS_WHITELIST
string "Whitelist of symbols to keep in ksymtab"
depends on TRIM_UNUSED_KSYMS
help
By default, all unused exported symbols will be un-exported from the
build when TRIM_UNUSED_KSYMS is selected.
UNUSED_KSYMS_WHITELIST allows to whitelist symbols that must be kept
exported at all times, even in absence of in-tree users. The value to
set here is the path to a text file containing the list of symbols,
one per line. The path can be absolute, or relative to the kernel
source tree.
Kconfig: Extend "menuconfig" for modules to simplify Kconfig file Given that the init/Kconfig file uses a "menuconfig" directive for modules already, might as well wrap all the submenu entries in an "if" to toss all those dependencies. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-08-05 01:31:32 +08:00
endif # MODULES
module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING Andrew worried about the overhead on small systems; only use the fancy code when either perf or tracing is enabled. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Requested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-27 09:39:37 +08:00
config MODULES_TREE_LOOKUP
def_bool y
depends on PERF_EVENTS || TRACING
cpumask: centralize cpu_online_map and cpu_possible_map Impact: cleanup Each SMP arch defines these themselves. Move them to a central location. Twists: 1) Some archs (m32, parisc, s390) set possible_map to all 1, so we add a CONFIG_INIT_ALL_POSSIBLE for this rather than break them. 2) mips and sparc32 '#define cpu_possible_map phys_cpu_present_map'. Those archs simply have phys_cpu_present_map replaced everywhere. 3) Alpha defined cpu_possible_map to cpu_present_map; this is tricky so I just manipulate them both in sync. 4) IA64, cris and m32r have gratuitous 'extern cpumask_t cpu_possible_map' declarations. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Grant Grundler <grundler@parisc-linux.org> Tested-by: Tony Luck <tony.luck@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Mike Travis <travis@sgi.com> Cc: ink@jurassic.park.msu.ru Cc: rmk@arm.linux.org.uk Cc: starvik@axis.com Cc: tony.luck@intel.com Cc: takata@linux-m32r.org Cc: ralf@linux-mips.org Cc: grundler@parisc-linux.org Cc: paulus@samba.org Cc: schwidefsky@de.ibm.com Cc: lethal@linux-sh.org Cc: wli@holomorphy.com Cc: davem@davemloft.net Cc: jdike@addtoit.com Cc: mingo@redhat.com
2008-12-13 18:49:41 +08:00
config INIT_ALL_POSSIBLE
bool
help
documentation: remove references to cpu_*_map. This has been obsolescent for a while, fix documentation and misc comments. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-03-29 13:08:31 +08:00
Back when each arch used to define their own cpu_online_mask and
cpu_possible_mask, some of them chose to initialize cpu_possible_mask
cpumask: centralize cpu_online_map and cpu_possible_map Impact: cleanup Each SMP arch defines these themselves. Move them to a central location. Twists: 1) Some archs (m32, parisc, s390) set possible_map to all 1, so we add a CONFIG_INIT_ALL_POSSIBLE for this rather than break them. 2) mips and sparc32 '#define cpu_possible_map phys_cpu_present_map'. Those archs simply have phys_cpu_present_map replaced everywhere. 3) Alpha defined cpu_possible_map to cpu_present_map; this is tricky so I just manipulate them both in sync. 4) IA64, cris and m32r have gratuitous 'extern cpumask_t cpu_possible_map' declarations. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Grant Grundler <grundler@parisc-linux.org> Tested-by: Tony Luck <tony.luck@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Mike Travis <travis@sgi.com> Cc: ink@jurassic.park.msu.ru Cc: rmk@arm.linux.org.uk Cc: starvik@axis.com Cc: tony.luck@intel.com Cc: takata@linux-m32r.org Cc: ralf@linux-mips.org Cc: grundler@parisc-linux.org Cc: paulus@samba.org Cc: schwidefsky@de.ibm.com Cc: lethal@linux-sh.org Cc: wli@holomorphy.com Cc: davem@davemloft.net Cc: jdike@addtoit.com Cc: mingo@redhat.com
2008-12-13 18:49:41 +08:00
with all 1s, and others with all 0s. When they were centralised,
it was better to provide this option than to break all the archs
trivial: fix typos/grammar errors in Kconfig texts Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-01-26 18:12:25 +08:00
and have several arch maintainers pursuing me down dark alleys.
cpumask: centralize cpu_online_map and cpu_possible_map Impact: cleanup Each SMP arch defines these themselves. Move them to a central location. Twists: 1) Some archs (m32, parisc, s390) set possible_map to all 1, so we add a CONFIG_INIT_ALL_POSSIBLE for this rather than break them. 2) mips and sparc32 '#define cpu_possible_map phys_cpu_present_map'. Those archs simply have phys_cpu_present_map replaced everywhere. 3) Alpha defined cpu_possible_map to cpu_present_map; this is tricky so I just manipulate them both in sync. 4) IA64, cris and m32r have gratuitous 'extern cpumask_t cpu_possible_map' declarations. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Grant Grundler <grundler@parisc-linux.org> Tested-by: Tony Luck <tony.luck@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Mike Travis <travis@sgi.com> Cc: ink@jurassic.park.msu.ru Cc: rmk@arm.linux.org.uk Cc: starvik@axis.com Cc: tony.luck@intel.com Cc: takata@linux-m32r.org Cc: ralf@linux-mips.org Cc: grundler@parisc-linux.org Cc: paulus@samba.org Cc: schwidefsky@de.ibm.com Cc: lethal@linux-sh.org Cc: wli@holomorphy.com Cc: davem@davemloft.net Cc: jdike@addtoit.com Cc: mingo@redhat.com
2008-12-13 18:49:41 +08:00
[BLOCK] Move all core block layer code to new block/ directory drivers/block/ is right now a mix of core and driver parts. Lets move the core parts to a new top level directory. Al will move the fs/ related block parts to block/ next. Signed-off-by: Jens Axboe <axboe@suse.de>
2005-11-04 15:43:35 +08:00
source "block/Kconfig"
Move PREEMPT_NOTIFIERS into an always-included Kconfig Kconfig.preempt is not included on some archs (for example, m68k). On those archs, the Kconfig machinery complains that KVM selects an undefined symbol PREEMPT_NOTIFIERS (which lives in Kconfig.preempt). So move the offending symbol into a Kconfig file which is included by everyone. Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 14:27:31 +08:00
config PREEMPT_NOTIFIERS
bool
Preempt-RCU: implementation This patch implements a new version of RCU which allows its read-side critical sections to be preempted. It uses a set of counter pairs to keep track of the read-side critical sections and flips them when all tasks exit read-side critical section. The details of this implementation can be found in this paper - http://www.rdrop.com/users/paulmck/RCU/OLSrtRCU.2006.08.11a.pdf and the article- http://lwn.net/Articles/253651/ This patch was developed as a part of the -rt kernel development and meant to provide better latencies when read-side critical sections of RCU don't disable preemption. As a consequence of keeping track of RCU readers, the readers have a slight overhead (optimizations in the paper). This implementation co-exists with the "classic" RCU implementations and can be switched to at compiler. Also includes RCU tracing summarized in debugfs. [ akpm@linux-foundation.org: build fixes on non-preempt architectures ] Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com> Reviewed-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-26 04:08:24 +08:00
padata: Generic parallelization/serialization interface This patch introduces an interface to process data objects in parallel. The parallelized objects return after serialization in the same order as they were before the parallelization. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-01-06 16:47:10 +08:00
config PADATA
depends on SMP
bool
X.509: Add simple ASN.1 grammar compiler Add a simple ASN.1 grammar compiler. This produces a bytecode output that can be fed to a decoder to inform the decoder how to interpret the ASN.1 stream it is trying to parse. Action functions can be specified in the grammar by interpolating: ({ foo }) after a type, for example: SubjectPublicKeyInfo ::= SEQUENCE { algorithm AlgorithmIdentifier, subjectPublicKey BIT STRING ({ do_key_data }) } The decoder is expected to call these after matching this type and parsing the contents if it is a constructed type. The grammar compiler does not currently support the SET type (though it does support SET OF) as I can't see a good way of tracking which members have been encountered yet without using up extra stack space. Currently, the grammar compiler will fail if more than 256 bytes of bytecode would be produced or more than 256 actions have been specified as it uses 8-bit jump values and action indices to keep space usage down. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-22 06:31:13 +08:00
config ASN1
tristate
help
Build a simple ASN.1 grammar compiler that produces a bytecode output
that can be interpreted by the ASN.1 stream decoder and used to
inform it as to what tags are to be expected in a stream and what
functions to call on what tags.
locking: Make inlining decision Kconfig based commit 892a7c67 (locking: Allow arch-inlined spinlocks) implements the selection of which lock functions are inlined based on defines in arch/.../spinlock.h: #define __always_inline__LOCK_FUNCTION Despite of the name __always_inline__* the lock functions can be built out of line depending on config options. Also if the arch does not set some inline defines the generic code might set them; again depending on config options. This makes it unnecessary hard to figure out when and which lock functions are inlined. Aside of that it makes it way harder and messier for -rt to manipulate the lock functions. Convert the inlining decision to CONFIG switches. Each lock function is inlined depending on CONFIG_INLINE_*. The configs implement the existing dependencies. The architecture code can select ARCH_INLINE_* to signal that it wants the corresponding lock function inlined. ARCH_INLINE_* is necessary as Kconfig ignores "depends on" restrictions when a config element is selected. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20091109151428.504477141@linutronix.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2009-11-09 23:21:34 +08:00
source "kernel/Kconfig.locks"
locking: Introduce sync_core_before_usermode() Introduce an architecture function that ensures the current CPU issues a core serializing instruction before returning to usermode. This is needed for the membarrier "sync_core" command. Architectures defining the sync_core_before_usermode() static inline need to select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Andrew Hunter <ahh@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Avi Kivity <avi@scylladb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dave Watson <davejwatson@fb.com> Cc: David Sehr <sehr@google.com> Cc: Greg Hackmann <ghackmann@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maged Michael <maged.michael@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/20180129202020.8515-7-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-30 04:20:15 +08:00
bpf: Restrict bpf_probe_read{, str}() only to archs where they work Given the legacy bpf_probe_read{,str}() BPF helpers are broken on archs with overlapping address ranges, we should really take the next step to disable them from BPF use there. To generally fix the situation, we've recently added new helper variants bpf_probe_read_{user,kernel}() and bpf_probe_read_{user,kernel}_str(). For details on them, see 6ae08ae3dea2 ("bpf: Add probe_read_{user, kernel} and probe_read_{user,kernel}_str helpers"). Given bpf_probe_read{,str}() have been around for ~5 years by now, there are plenty of users at least on x86 still relying on them today, so we cannot remove them entirely w/o breaking the BPF tracing ecosystem. However, their use should be restricted to archs with non-overlapping address ranges where they are working in their current form. Therefore, move this behind a CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE and have x86, arm64, arm select it (other archs supporting it can follow-up on it as well). For the remaining archs, they can workaround easily by relying on the feature probe from bpftool which spills out defines that can be used out of BPF C code to implement the drop-in replacement for old/new kernels via: bpftool feature probe macro Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/bpf/20200515101118.6508-2-daniel@iogearbox.net
2020-05-15 18:11:16 +08:00
config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
bool
locking: Introduce sync_core_before_usermode() Introduce an architecture function that ensures the current CPU issues a core serializing instruction before returning to usermode. This is needed for the membarrier "sync_core" command. Architectures defining the sync_core_before_usermode() static inline need to select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Andrew Hunter <ahh@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Avi Kivity <avi@scylladb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dave Watson <davejwatson@fb.com> Cc: David Sehr <sehr@google.com> Cc: Greg Hackmann <ghackmann@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maged Michael <maged.michael@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/20180129202020.8515-7-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-30 04:20:15 +08:00
config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
bool
syscalls/core: Introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y It may be useful for an architecture to override the definitions of the SYSCALL_DEFINE0() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>, in particular to use a different calling convention for syscalls. This patch provides a mechanism to do so: It introduces CONFIG_ARCH_HAS_SYSCALL_WRAPPER. If it is enabled, <asm/sycall_wrapper.h> is included in <linux/syscalls.h> and may be used to define the macros mentioned above. Moreover, as the syscall calling convention may be different if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is set, the syscall function prototypes in <linux/syscalls.h> are #ifndef'd out in that case. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180405095307.3730-3-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-05 17:53:01 +08:00
# It may be useful for an architecture to override the definitions of the
syscalls/core: Prepare CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y for compat syscalls It may be useful for an architecture to override the definitions of the COMPAT_SYSCALL_DEFINE0() and __COMPAT_SYSCALL_DEFINEx() macros in <linux/compat.h>, in particular to use a different calling convention for syscalls. This patch provides a mechanism to do so, based on the previously introduced CONFIG_ARCH_HAS_SYSCALL_WRAPPER. If it is enabled, <asm/sycall_wrapper.h> is included in <linux/compat.h> and may be used to define the macros mentioned above. Moreover, as the syscall calling convention may be different if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is set, the compat syscall function prototypes in <linux/compat.h> are #ifndef'd out in that case. As some of the syscalls and/or compat syscalls may not be present, the COND_SYSCALL() and COND_SYSCALL_COMPAT() macros in kernel/sys_ni.c as well as the SYS_NI() and COMPAT_SYS_NI() macros in kernel/time/posix-stubs.c can be re-defined in <asm/syscall_wrapper.h> iff CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180405095307.3730-5-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-05 17:53:03 +08:00
# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
# different calling convention for syscalls. They can also override the
# macros for not-implemented syscalls in kernel/sys_ni.c and
# kernel/time/posix-stubs.c. All these overrides need to be available in
# <asm/syscall_wrapper.h>.
syscalls/core: Introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y It may be useful for an architecture to override the definitions of the SYSCALL_DEFINE0() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>, in particular to use a different calling convention for syscalls. This patch provides a mechanism to do so: It introduces CONFIG_ARCH_HAS_SYSCALL_WRAPPER. If it is enabled, <asm/sycall_wrapper.h> is included in <linux/syscalls.h> and may be used to define the macros mentioned above. Moreover, as the syscall calling convention may be different if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is set, the syscall function prototypes in <linux/syscalls.h> are #ifndef'd out in that case. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180405095307.3730-3-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-05 17:53:01 +08:00
config ARCH_HAS_SYSCALL_WRAPPER
def_bool n