If a user puts init=/whatever on the command line and /whatever can't be
run, then the kernel will try a few default options before giving up. If
init=/whatever came from a bootloader prompt, then this is unexpected but
probably harmless. On the other hand, if it comes from a script (e.g. a
tool like virtme or perhaps a future kselftest script), then the fallbacks
are likely to exist, but they'll do the wrong thing. For example, they
might unexpectedly invoke systemd.
This adds a config option CONFIG_INIT_FALLBACK. If unset, then a failure
to run the specified init= process be fatal.
The tentative plan is to remove CONFIG_INIT_FALLBACK for 3.20.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Rob Landley <rob@landley.net>
Cc: Chuck Ebbert <cebbert.lkml@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that the external page_cgroup data structure and its lookup is
gone, let the generic bad_page() check for page->mem_cgroup sanity.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Tejun Heo <tj@kernel.org>
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>
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>
All memory accounting and limiting has been switched over to the
lockless page counters. Bye, res_counter!
[akpm@linux-foundation.org: update Documentation/cgroups/memory.txt]
[mhocko@suse.cz: ditch the last remainings of res_counter]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Abandon the spinlock-protected byte counters in favor of the unlocked
page counters in the hugetlb controller as well.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
PREEMPT_RCU and TREE_PREEMPT_RCU serve the same function after
TINY_PREEMPT_RCU has been removed. This patch removes TREE_PREEMPT_RCU
and uses PREEMPT_RCU config option in its place.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Rename CONFIG_RCU_BOOST_PRIO to CONFIG_RCU_KTHREAD_PRIO and use this
value for both the per-CPU kthreads (rcuc/N) and the rcu boosting
threads (rcub/n).
Also, create the module_parameter rcutree.kthread_prio to be used on
the kernel command line at boot to set a new value (rcutree.kthread_prio=N).
Signed-off-by: Clark Williams <clark.williams@gmail.com>
[ paulmck: Ported to rcu/dev, applied Paul Bolle and Peter Zijlstra feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Every choice item of the "Build-forced no-CBs CPUs" choice had a
dependency to RCU_NOCB_CPU. It's more comprehensible if the choice
itself has the dependency instead of every choice item. The choice
itself doesn't need to be visible if there are no items selectable
(i.e. on arch/frv) or RCU_NOCB_CPU is not defined.
Signed-off-by: Stefan Hengelein <stefan.hengelein@fau.de>
Signed-off-by: Andreas Ruprecht <rupran@einserver.de>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>
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>
Pull RCU updates from Ingo Molnar:
"The main changes in this cycle were:
- changes related to No-CBs CPUs and NO_HZ_FULL
- RCU-tasks implementation
- torture-test updates
- miscellaneous fixes
- locktorture updates
- RCU documentation updates"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits)
workqueue: Use cond_resched_rcu_qs macro
workqueue: Add quiescent state between work items
locktorture: Cleanup header usage
locktorture: Cannot hold read and write lock
locktorture: Fix __acquire annotation for spinlock irq
locktorture: Support rwlocks
rcu: Eliminate deadlock between CPU hotplug and expedited grace periods
locktorture: Document boot/module parameters
rcutorture: Rename rcutorture_runnable parameter
locktorture: Add test scenario for rwsem_lock
locktorture: Add test scenario for mutex_lock
locktorture: Make torture scripting account for new _runnable name
locktorture: Introduce torture context
locktorture: Support rwsems
locktorture: Add infrastructure for torturing read locks
torture: Address race in module cleanup
locktorture: Make statistics generic
locktorture: Teach about lock debugging
locktorture: Support mutexes
locktorture: Add documentation
...
ARCH_USES_NUMA_PROT_NONE was defined for architectures that implemented
_PAGE_NUMA using _PROT_NONE. This saved using an additional PTE bit and
relied on the fact that PROT_NONE vmas were skipped by the NUMA hinting
fault scanner. This was found to be conceptually confusing with a lot of
implicit assumptions and it was asked that an alternative be found.
Commit c46a7c81 "x86: define _PAGE_NUMA by reusing software bits on the
PMD and PTE levels" redefined _PAGE_NUMA on x86 to be one of the swap PTE
bits and shrunk the maximum possible swap size but it did not go far
enough. There are no architectures that reuse _PROT_NONE as _PROT_NUMA
but the relics still exist.
This patch removes ARCH_USES_NUMA_PROT_NONE and removes some unnecessary
duplication in powerpc vs the generic implementation by defining the types
the core NUMA helpers expected to exist from x86 with their ppc64
equivalent. This necessitated that a PTE bit mask be created that
identified the bits that distinguish present from NUMA pte entries but it
is expected this will only differ between arches based on _PAGE_PROTNONE.
The naming for the generic helpers was taken from x86 originally but ppc64
has types that are equivalent for the purposes of the helper so they are
mapped instead of duplicating code.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cheers,
Rusty.
PS. My virtio-next tree is empty: DaveM took the patches I had. There might
be a virtio-rng starvation fix, but so far it's a bit voodoo so I will
get to that in the next two days or it will wait.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module update from Rusty Russell:
"Nothing major: support for compressing modules, and auto-tainting
params.
PS. My virtio-next tree is empty: DaveM took the patches I had. There
might be a virtio-rng starvation fix, but so far it's a bit voodoo
so I will get to that in the next two days or it will wait"
* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
moduleparam: Resolve missing-field-initializer warning
kbuild: handle module compression while running 'make modules_install'.
modinst: wrap long lines in order to enhance cmd_modules_install
modsign: lookup lines ending in .ko in .mod files
modpost: simplify file name generation of *.mod.c files
modpost: reduce visibility of symbols and constify r/o arrays
param: check for tainting before calling set op.
drm/i915: taint the kernel if unsafe module parameters are set
module: add module_param_unsafe and module_param_named_unsafe
module: make it possible to have unsafe, tainting module params
module: rename KERNEL_PARAM_FL_NOARG to avoid confusion
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Merge tag 'tiny/for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux
Pull "tinification" patches from Josh Triplett.
Work on making smaller kernels.
* tag 'tiny/for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux:
bloat-o-meter: Ignore syscall aliases SyS_ and compat_SyS_
mm: Support compiling out madvise and fadvise
x86: Support compiling out human-friendly processor feature names
x86: Drop support for /proc files when !CONFIG_PROC_FS
x86, boot: Don't compile early_serial_console.c when !CONFIG_EARLY_PRINTK
x86, boot: Don't compile aslr.c when !CONFIG_RANDOMIZE_BASE
x86, boot: Use the usual -y -n mechanism for objects in vmlinux
x86: Add "make tinyconfig" to configure the tiniest possible kernel
x86, platform, kconfig: move kvmconfig functionality to a helper
commit 03b8c7b623 ("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>
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>
Commit b58cc46c5f (rcu: Don't offload callbacks unless specifically
requested) failed to adjust the callback lists of the CPUs that are
known to be no-CBs CPUs only because they are also nohz_full= CPUs.
This failure can result in callbacks that are posted during early boot
getting stranded on nxtlist for CPUs whose no-CBs property becomes
apparent late, and there can also be spurious warnings about offline
CPUs posting callbacks.
This commit fixes these problems by adding an early-boot rcu_init_nohz()
that properly initializes the no-CBs CPUs.
Note that kernels built with CONFIG_RCU_NOCB_CPU_ALL=y or with
CONFIG_RCU_NOCB_CPU=n do not exhibit this bug. Neither do kernels
booted without the nohz_full= boot parameter.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This commit adds a new RCU-tasks flavor of RCU, which provides
call_rcu_tasks(). This RCU flavor's quiescent states are voluntary
context switch (not preemption!) and userspace execution (not the idle
loop -- use some sort of schedule_on_each_cpu() if you need to handle the
idle tasks. Note that unlike other RCU flavors, these quiescent states
occur in tasks, not necessarily CPUs. Includes fixes from Steven Rostedt.
This RCU flavor is assumed to have very infrequent latency-tolerant
updaters. This assumption permits significant simplifications, including
a single global callback list protected by a single global lock, along
with a single task-private linked list containing all tasks that have not
yet passed through a quiescent state. If experience shows this assumption
to be incorrect, the required additional complexity will be added.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>
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>
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>
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>
Enabling NO_HZ_FULL currently has the side effect of enabling callback
offloading on all CPUs. This results in lots of additional rcuo kthreads,
and can also increase context switching and wakeups, even in cases where
callback offloading is neither needed nor particularly desirable. This
commit therefore enables callback offloading on a given CPU only if
specifically requested at build time or boot time, or if that CPU has
been specifically designated (again, either at build time or boot time)
as a nohz_full CPU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>
CONFIG_MM_OWNER makes no sense. It is not user-selectable, it is only
selected by CONFIG_MEMCG automatically. So we can kill this option in
init/Kconfig and do s/CONFIG_MM_OWNER/CONFIG_MEMCG/ globally.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
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>
Kmemcg is currently under development and lacks some important features.
In particular, it does not have support of kmem reclaim on memory pressure
inside cgroup, which practically makes it unusable in real life. Let's
warn about it in both Kconfig and Documentation to prevent complaints
arising.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Pull audit updates from Eric Paris.
* git://git.infradead.org/users/eparis/audit: (28 commits)
AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC
audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range
audit: do not cast audit_rule_data pointers pointlesly
AUDIT: Allow login in non-init namespaces
audit: define audit_is_compat in kernel internal header
kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c
sched: declare pid_alive as inline
audit: use uapi/linux/audit.h for AUDIT_ARCH declarations
syscall_get_arch: remove useless function arguments
audit: remove stray newline from audit_log_execve_info() audit_panic() call
audit: remove stray newlines from audit_log_lost messages
audit: include subject in login records
audit: remove superfluous new- prefix in AUDIT_LOGIN messages
audit: allow user processes to log from another PID namespace
audit: anchor all pid references in the initial pid namespace
audit: convert PPIDs to the inital PID namespace.
pid: get pid_t ppid of task in init_pid_ns
audit: rename the misleading audit_get_context() to audit_take_context()
audit: Add generic compat syscall support
audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL
...
"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>
Merge first patch-bomb from Andrew Morton:
- Various misc bits
- kmemleak fixes
- small befs, codafs, cifs, efs, freexxfs, hfsplus, minixfs, reiserfs things
- fanotify
- I appear to have become SuperH maintainer
- ocfs2 updates
- direct-io tweaks
- a bit of the MM queue
- printk updates
- MAINTAINERS maintenance
- some backlight things
- lib/ updates
- checkpatch updates
- the rtc queue
- nilfs2 updates
- Small Documentation/ updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (237 commits)
Documentation/SubmittingPatches: remove references to patch-scripts
Documentation/SubmittingPatches: update some dead URLs
Documentation/filesystems/ntfs.txt: remove changelog reference
Documentation/kmemleak.txt: updates
fs/reiserfs/super.c: add __init to init_inodecache
fs/reiserfs: move prototype declaration to header file
fs/hfsplus/attributes.c: add __init to hfsplus_create_attr_tree_cache()
fs/hfsplus/extents.c: fix concurrent acess of alloc_blocks
fs/hfsplus/extents.c: remove unused variable in hfsplus_get_block
nilfs2: update project's web site in nilfs2.txt
nilfs2: update MAINTAINERS file entries fix
nilfs2: verify metadata sizes read from disk
nilfs2: add FITRIM ioctl support for nilfs2
nilfs2: add nilfs_sufile_trim_fs to trim clean segs
nilfs2: implementation of NILFS_IOCTL_SET_SUINFO ioctl
nilfs2: add nilfs_sufile_set_suinfo to update segment usage
nilfs2: add struct nilfs_suinfo_update and flags
nilfs2: update MAINTAINERS file entries
fs/coda/inode.c: add __init to init_inodecache()
BEFS: logging cleanup
...
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>
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>
Pull cgroup updates from Tejun Heo:
"A lot updates for cgroup:
- The biggest one is cgroup's conversion to kernfs. cgroup took
after the long abandoned vfs-entangled sysfs implementation and
made it even more convoluted over time. cgroup's internal objects
were fused with vfs objects which also brought in vfs locking and
object lifetime rules. Naturally, there are places where vfs rules
don't fit and nasty hacks, such as credential switching or lock
dance interleaving inode mutex and cgroup_mutex with object serial
number comparison thrown in to decide whether the operation is
actually necessary, needed to be employed.
After conversion to kernfs, internal object lifetime and locking
rules are mostly isolated from vfs interactions allowing shedding
of several nasty hacks and overall simplification. This will also
allow implmentation of operations which may affect multiple cgroups
which weren't possible before as it would have required nesting
i_mutexes.
- Various simplifications including dropping of module support,
easier cgroup name/path handling, simplified cgroup file type
handling and task_cg_lists optimization.
- Prepatory changes for the planned unified hierarchy, which is still
a patchset away from being actually operational. The dummy
hierarchy is updated to serve as the default unified hierarchy.
Controllers which aren't claimed by other hierarchies are
associated with it, which BTW was what the dummy hierarchy was for
anyway.
- Various fixes from Li and others. This pull request includes some
patches to add missing slab.h to various subsystems. This was
triggered xattr.h include removal from cgroup.h. cgroup.h
indirectly got included a lot of files which brought in xattr.h
which brought in slab.h.
There are several merge commits - one to pull in kernfs updates
necessary for converting cgroup (already in upstream through
driver-core), others for interfering changes in the fixes branch"
* 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (74 commits)
cgroup: remove useless argument from cgroup_exit()
cgroup: fix spurious lockdep warning in cgroup_exit()
cgroup: Use RCU_INIT_POINTER(x, NULL) in cgroup.c
cgroup: break kernfs active_ref protection in cgroup directory operations
cgroup: fix cgroup_taskset walking order
cgroup: implement CFTYPE_ONLY_ON_DFL
cgroup: make cgrp_dfl_root mountable
cgroup: drop const from @buffer of cftype->write_string()
cgroup: rename cgroup_dummy_root and related names
cgroup: move ->subsys_mask from cgroupfs_root to cgroup
cgroup: treat cgroup_dummy_root as an equivalent hierarchy during rebinding
cgroup: remove NULL checks from [pr_cont_]cgroup_{name|path}()
cgroup: use cgroup_setup_root() to initialize cgroup_dummy_root
cgroup: reorganize cgroup bootstrapping
cgroup: relocate setting of CGRP_DEAD
cpuset: use rcu_read_lock() to protect task_cs()
cgroup_freezer: document freezer_fork() subtleties
cgroup: update cgroup_transfer_tasks() to either succeed or fail
cgroup: drop task_lock() protection around task->cgroups
cgroup: update how a newly forked task gets associated with css_set
...
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>
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>
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 0ab02ca8f8 ("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>
Pull user namespaces work from Eric Biederman:
"The work to convert the kernel to use kuid_t and kgid_t has been
finished since 3.12 so it is time to remove the scaffolding that
allowed the work to progress incrementally.
The first patch on this branch just removes the scaffolding, ensuring
we will always get compile errors if people accidentally try the
userspace and the kernel uid and gid types. The second patch an
overlooked and unused chunk of mips code that that fails to build
after the first patch.
The code hasn't been in linux-next for long (as I was out of it and
could not sheppared the cold properly) but the patch has been around
for a long time just waiting for the day when I had finished the
uid/gid conversions. Putting the code in linux-next did find the
compile failure on mips so I took the time to get that fix reviewed
and included. Beyond that I am not too worried about errors because
all these two patches do is delete a modest amount of code"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
MIPS: VPE: Remove vpe_getuid and vpe_getgid
userns: userns: Remove UIDGID_STRICT_TYPE_CHECKS
Pull cgroup updates from Tejun Heo:
"The bulk of changes are cleanups and preparations for the upcoming
kernfs conversion.
- cgroup_event mechanism which is and will be used only by memcg is
moved to memcg.
- pidlist handling is updated so that it can be served by seq_file.
Also, the list is not sorted if sane_behavior. cgroup
documentation explicitly states that the file is not sorted but it
has been for quite some time.
- All cgroup file handling now happens on top of seq_file. This is
to prepare for kernfs conversion. In addition, all operations are
restructured so that they map 1-1 to kernfs operations.
- Other cleanups and low-pri fixes"
* 'for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (40 commits)
cgroup: trivial style updates
cgroup: remove stray references to css_id
doc: cgroups: Fix typo in doc/cgroups
cgroup: fix fail path in cgroup_load_subsys()
cgroup: fix missing unlock on error in cgroup_load_subsys()
cgroup: remove for_each_root_subsys()
cgroup: implement for_each_css()
cgroup: factor out cgroup_subsys_state creation into create_css()
cgroup: combine css handling loops in cgroup_create()
cgroup: reorder operations in cgroup_create()
cgroup: make for_each_subsys() useable under cgroup_root_mutex
cgroup: css iterations and css_from_dir() are safe under cgroup_mutex
cgroup: unify pidlist and other file handling
cgroup: replace cftype->read_seq_string() with cftype->seq_show()
cgroup: attach cgroup_open_file to all cgroup files
cgroup: generalize cgroup_pidlist_open_file
cgroup: unify read path so that seq_file is always used
cgroup: unify cgroup_write_X64() and cgroup_write_string()
cgroup: remove cftype->read(), ->read_map() and ->write()
hugetlb_cgroup: convert away from cftype->read()
...
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>
Removing UIDGID_STRICT_TYPE_CHECKS simplifies the code and always
generates a compile error if the uids and kuids or gids and kgids are
mixed by accident. Now that the appropriate conversions have been
placed throughout the kernel there is no longer a need for a mode where
we don't detect them as compile errors.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Merge v3.12 based patch series to move cgroup_event implementation to
memcg into for-3.14. The following two commits cause a conflict in
kernel/cgroup.c
2ff2a7d03b ("cgroup: kill css_id")
79bd9814e5 ("cgroup, memcg: move cgroup_event implementation to memcg")
Each patch removes a struct definition from kernel/cgroup.c. As the
two are adjacent, they cause a context conflict. Easily resolved by
removing both structs.
Signed-off-by: Tejun Heo <tj@kernel.org>
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>
Pull security subsystem updates from James Morris:
"In this patchset, we finally get an SELinux update, with Paul Moore
taking over as maintainer of that code.
Also a significant update for the Keys subsystem, as well as
maintenance updates to Smack, IMA, TPM, and Apparmor"
and since I wanted to know more about the updates to key handling,
here's the explanation from David Howells on that:
"Okay. There are a number of separate bits. I'll go over the big bits
and the odd important other bit, most of the smaller bits are just
fixes and cleanups. If you want the small bits accounting for, I can
do that too.
(1) Keyring capacity expansion.
KEYS: Consolidate the concept of an 'index key' for key access
KEYS: Introduce a search context structure
KEYS: Search for auth-key by name rather than target key ID
Add a generic associative array implementation.
KEYS: Expand the capacity of a keyring
Several of the patches are providing an expansion of the capacity of a
keyring. Currently, the maximum size of a keyring payload is one page.
Subtract a small header and then divide up into pointers, that only gives
you ~500 pointers on an x86_64 box. However, since the NFS idmapper uses
a keyring to store ID mapping data, that has proven to be insufficient to
the cause.
Whatever data structure I use to handle the keyring payload, it can only
store pointers to keys, not the keys themselves because several keyrings
may point to a single key. This precludes inserting, say, and rb_node
struct into the key struct for this purpose.
I could make an rbtree of records such that each record has an rb_node
and a key pointer, but that would use four words of space per key stored
in the keyring. It would, however, be able to use much existing code.
I selected instead a non-rebalancing radix-tree type approach as that
could have a better space-used/key-pointer ratio. I could have used the
radix tree implementation that we already have and insert keys into it by
their serial numbers, but that means any sort of search must iterate over
the whole radix tree. Further, its nodes are a bit on the capacious side
for what I want - especially given that key serial numbers are randomly
allocated, thus leaving a lot of empty space in the tree.
So what I have is an associative array that internally is a radix-tree
with 16 pointers per node where the index key is constructed from the key
type pointer and the key description. This means that an exact lookup by
type+description is very fast as this tells us how to navigate directly to
the target key.
I made the data structure general in lib/assoc_array.c as far as it is
concerned, its index key is just a sequence of bits that leads to a
pointer. It's possible that someone else will be able to make use of it
also. FS-Cache might, for example.
(2) Mark keys as 'trusted' and keyrings as 'trusted only'.
KEYS: verify a certificate is signed by a 'trusted' key
KEYS: Make the system 'trusted' keyring viewable by userspace
KEYS: Add a 'trusted' flag and a 'trusted only' flag
KEYS: Separate the kernel signature checking keyring from module signing
These patches allow keys carrying asymmetric public keys to be marked as
being 'trusted' and allow keyrings to be marked as only permitting the
addition or linkage of trusted keys.
Keys loaded from hardware during kernel boot or compiled into the kernel
during build are marked as being trusted automatically. New keys can be
loaded at runtime with add_key(). They are checked against the system
keyring contents and if their signatures can be validated with keys that
are already marked trusted, then they are marked trusted also and can
thus be added into the master keyring.
Patches from Mimi Zohar make this usable with the IMA keyrings also.
(3) Remove the date checks on the key used to validate a module signature.
X.509: Remove certificate date checks
It's not reasonable to reject a signature just because the key that it was
generated with is no longer valid datewise - especially if the kernel
hasn't yet managed to set the system clock when the first module is
loaded - so just remove those checks.
(4) Make it simpler to deal with additional X.509 being loaded into the kernel.
KEYS: Load *.x509 files into kernel keyring
KEYS: Have make canonicalise the paths of the X.509 certs better to deduplicate
The builder of the kernel now just places files with the extension ".x509"
into the kernel source or build trees and they're concatenated by the
kernel build and stuffed into the appropriate section.
(5) Add support for userspace kerberos to use keyrings.
KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches
KEYS: Implement a big key type that can save to tmpfs
Fedora went to, by default, storing kerberos tickets and tokens in tmpfs.
We looked at storing it in keyrings instead as that confers certain
advantages such as tickets being automatically deleted after a certain
amount of time and the ability for the kernel to get at these tokens more
easily.
To make this work, two things were needed:
(a) A way for the tickets to persist beyond the lifetime of all a user's
sessions so that cron-driven processes can still use them.
The problem is that a user's session keyrings are deleted when the
session that spawned them logs out and the user's user keyring is
deleted when the UID is deleted (typically when the last log out
happens), so neither of these places is suitable.
I've added a system keyring into which a 'persistent' keyring is
created for each UID on request. Each time a user requests their
persistent keyring, the expiry time on it is set anew. If the user
doesn't ask for it for, say, three days, the keyring is automatically
expired and garbage collected using the existing gc. All the kerberos
tokens it held are then also gc'd.
(b) A key type that can hold really big tickets (up to 1MB in size).
The problem is that Active Directory can return huge tickets with lots
of auxiliary data attached. We don't, however, want to eat up huge
tracts of unswappable kernel space for this, so if the ticket is
greater than a certain size, we create a swappable shmem file and dump
the contents in there and just live with the fact we then have an
inode and a dentry overhead. If the ticket is smaller than that, we
slap it in a kmalloc()'d buffer"
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (121 commits)
KEYS: Fix keyring content gc scanner
KEYS: Fix error handling in big_key instantiation
KEYS: Fix UID check in keyctl_get_persistent()
KEYS: The RSA public key algorithm needs to select MPILIB
ima: define '_ima' as a builtin 'trusted' keyring
ima: extend the measurement list to include the file signature
kernel/system_certificate.S: use real contents instead of macro GLOBAL()
KEYS: fix error return code in big_key_instantiate()
KEYS: Fix keyring quota misaccounting on key replacement and unlink
KEYS: Fix a race between negating a key and reading the error set
KEYS: Make BIG_KEYS boolean
apparmor: remove the "task" arg from may_change_ptraced_domain()
apparmor: remove parent task info from audit logging
apparmor: remove tsk field from the apparmor_audit_struct
apparmor: fix capability to not use the current task, during reporting
Smack: Ptrace access check mode
ima: provide hash algo info in the xattr
ima: enable support for larger default filedata hash algorithms
ima: define kernel parameter 'ima_template=' to change configured default
ima: add Kconfig default measurement list template
...
Pull audit updates from Eric Paris:
"Nothing amazing. Formatting, small bug fixes, couple of fixes where
we didn't get records due to some old VFS changes, and a change to how
we collect execve info..."
Fixed conflict in fs/exec.c as per Eric and linux-next.
* git://git.infradead.org/users/eparis/audit: (28 commits)
audit: fix type of sessionid in audit_set_loginuid()
audit: call audit_bprm() only once to add AUDIT_EXECVE information
audit: move audit_aux_data_execve contents into audit_context union
audit: remove unused envc member of audit_aux_data_execve
audit: Kill the unused struct audit_aux_data_capset
audit: do not reject all AUDIT_INODE filter types
audit: suppress stock memalloc failure warnings since already managed
audit: log the audit_names record type
audit: add child record before the create to handle case where create fails
audit: use given values in tty_audit enable api
audit: use nlmsg_len() to get message payload length
audit: use memset instead of trying to initialize field by field
audit: fix info leak in AUDIT_GET requests
audit: update AUDIT_INODE filter rule to comparator function
audit: audit feature to set loginuid immutable
audit: audit feature to only allow unsetting the loginuid
audit: allow unsetting the loginuid (with priv)
audit: remove CONFIG_AUDIT_LOGINUID_IMMUTABLE
audit: loginuid functions coding style
selinux: apply selinux checks on new audit message types
...
This reverts commit 69f0554ec2.
This patch breaks randconfig on at least the x86-64 architecture, and
most likely on others. There is work underway to support uncompressed
kernels in a generic way, but it looks like it will amount to
rewriting the support from scratch; see the LKML thread in the Link:
for info.
Therefore, revert this change and wait for the fix.
Reported-by: Pavel Roskin <proski@gnu.org>
Cc: Christian Ruppert <christian.ruppert@abilis.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20131113113418.167b8ffd@IRBT4585
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull trivial tree updates from Jiri Kosina:
"Usual earth-shaking, news-breaking, rocket science pile from
trivial.git"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits)
doc: usb: Fix typo in Documentation/usb/gadget_configs.txt
doc: add missing files to timers/00-INDEX
timekeeping: Fix some trivial typos in comments
mm: Fix some trivial typos in comments
irq: Fix some trivial typos in comments
NUMA: fix typos in Kconfig help text
mm: update 00-INDEX
doc: Documentation/DMA-attributes.txt fix typo
DRM: comment: `halve' -> `half'
Docs: Kconfig: `devlopers' -> `developers'
doc: typo on word accounting in kprobes.c in mutliple architectures
treewide: fix "usefull" typo
treewide: fix "distingush" typo
mm/Kconfig: Grammar s/an/a/
kexec: Typo s/the/then/
Documentation/kvm: Update cpuid documentation for steal time and pv eoi
treewide: Fix common typo in "identify"
__page_to_pfn: Fix typo in comment
Correct some typos for word frequency
clk: fixed-factor: Fix a trivial typo
...
Some ARC users say they can boot faster with without kernel compression.
This probably depends on things like the FLASH chip they use etc.
Until now, kernel compression can only be disabled by removing "select
HAVE_<compression>" lines from the architecture Kconfig. So add the
Kconfig logic to permit disabling of kernel compression.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull timer changes from Ingo Molnar:
"Main changes in this cycle were:
- Updated full dynticks support.
- Event stream support for architected (ARM) timers.
- ARM clocksource driver updates.
- Move arm64 to using the generic sched_clock framework & resulting
cleanup in the generic sched_clock code.
- Misc fixes and cleanups"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
x86/time: Honor ACPI FADT flag indicating absence of a CMOS RTC
clocksource: sun4i: remove IRQF_DISABLED
clocksource: sun4i: Report the minimum tick that we can program
clocksource: sun4i: Select CLKSRC_MMIO
clocksource: Provide timekeeping for efm32 SoCs
clocksource: em_sti: convert to clk_prepare/unprepare
time: Fix signedness bug in sysfs_get_uname() and its callers
timekeeping: Fix some trivial typos in comments
alarmtimer: return EINVAL instead of ENOTSUPP if rtcdev doesn't exist
clocksource: arch_timer: Do not register arch_sys_counter twice
timer stats: Add a 'Collection: active/inactive' line to timer usage statistics
sched_clock: Remove sched_clock_func() hook
arch_timer: Move to generic sched_clock framework
clocksource: tcb_clksrc: Remove IRQF_DISABLED
clocksource: tcb_clksrc: Improve driver robustness
clocksource: tcb_clksrc: Replace clk_enable/disable with clk_prepare_enable/disable_unprepare
clocksource: arm_arch_timer: Use clocksource for suspend timekeeping
clocksource: dw_apb_timer_of: Mark a few more functions as __init
clocksource: Put nodes passed to CLOCKSOURCE_OF_DECLARE callbacks centrally
arm: zynq: Enable arm_global_timer
...
After trying to use this feature in Fedora we found the hard coding
policy like this into the kernel was a bad idea. Surprise surprise.
We ran into these problems because it was impossible to launch a
container as a logged in user and run a login daemon inside that container.
This reverts back to the old behavior before this option was added. The
option will be re-added in a userspace selectable manor such that
userspace can choose when it is and when it is not appropriate.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
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>
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>
Separate the kernel signature checking keyring from module signing so that it
can be used by code other than the module-signing code.
Signed-off-by: David Howells <dhowells@redhat.com>
Pull SLAB update from Pekka Enberg:
"Nothing terribly exciting here apart from Christoph's kmalloc
unification patches that brings sl[aou]b implementations closer to
each other"
* 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
slab: Use correct GFP_DMA constant
slub: remove verify_mem_not_deleted()
mm/sl[aou]b: Move kmallocXXX functions to common code
mm, slab_common: add 'unlikely' to size check of kmalloc_slab()
mm/slub.c: beautify code for removing redundancy 'break' statement.
slub: Remove unnecessary page NULL check
slub: don't use cpu partial pages on UP
mm/slub: beautify code for 80 column limitation and tab alignment
mm/slub: remove 'per_cpu' which is useless variable
Pull kconfig updates from Michal Marek:
"This is the kconfig part of kbuild for v3.12-rc1:
- post-3.11 search code fixes and micro-optimizations
- CONFIG_MODULES is no longer a special case; this is needed to
eventually fix the bug that using KCONFIG_ALLCONFIG breaks
allmodconfig
- long long is used to store hex and int values
- make silentoldconfig no longer warns when a symbol changes from
tristate to bool (it's a job for make oldconfig)
- scripts/diffconfig updated to work with newer Pythons
- scripts/config does not rely on GNU sed extensions"
* 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kconfig: do not allow more than one symbol to have 'option modules'
kconfig: regenerate bison parser
kconfig: do not special-case 'MODULES' symbol
diffconfig: Update script to support python versions 2.5 through 3.3
diffconfig: Gracefully exit if the default config files are not present
modules: do not depend on kconfig to set 'modules' option to symbol MODULES
kconfig: silence warning when parsing auto.conf when a symbol has changed type
scripts/config: use sed's POSIX interface
kconfig: switch to "long long" for sanity
kconfig: simplify symbol-search code
kconfig: don't allocate n+1 elements in temporary array
kconfig: minor style fixes in symbol-search code
kconfig/[mn]conf: shorten title in search-box
kconfig: avoid multiple calls to strlen
Documentation/kconfig: more concise and straightforward search explanation
For 3.12-rc1 there are a number of bugfixes in addition to work to ease usage
of shared code between libxfs and the kernel, the rest of the work to enable
project and group quotas to be used simultaneously, performance optimisations
in the log and the CIL, directory entry file type support, fixes for log space
reservations, some spelling/grammar cleanups, and the addition of user
namespace support.
- introduce readahead to log recovery
- add directory entry file type support
- fix a number of spelling errors in comments
- introduce new Q_XGETQSTATV quotactl for project quotas
- add USER_NS support
- log space reservation rework
- CIL optimisations
- kernel/userspace libxfs rework
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Merge tag 'xfs-for-linus-v3.12-rc1' of git://oss.sgi.com/xfs/xfs
Pull xfs updates from Ben Myers:
"For 3.12-rc1 there are a number of bugfixes in addition to work to
ease usage of shared code between libxfs and the kernel, the rest of
the work to enable project and group quotas to be used simultaneously,
performance optimisations in the log and the CIL, directory entry file
type support, fixes for log space reservations, some spelling/grammar
cleanups, and the addition of user namespace support.
- introduce readahead to log recovery
- add directory entry file type support
- fix a number of spelling errors in comments
- introduce new Q_XGETQSTATV quotactl for project quotas
- add USER_NS support
- log space reservation rework
- CIL optimisations
- kernel/userspace libxfs rework"
* tag 'xfs-for-linus-v3.12-rc1' of git://oss.sgi.com/xfs/xfs: (112 commits)
xfs: XFS_MOUNT_QUOTA_ALL needed by userspace
xfs: dtype changed xfs_dir2_sfe_put_ino to xfs_dir3_sfe_put_ino
Fix wrong flag ASSERT in xfs_attr_shortform_getvalue
xfs: finish removing IOP_* macros.
xfs: inode log reservations are too small
xfs: check correct status variable for xfs_inobt_get_rec() call
xfs: inode buffers may not be valid during recovery readahead
xfs: check LSN ordering for v5 superblocks during recovery
xfs: btree block LSN escaping to disk uninitialised
XFS: Assertion failed: first <= last && last < BBTOB(bp->b_length), file: fs/xfs/xfs_trans_buf.c, line: 568
xfs: fix bad dquot buffer size in log recovery readahead
xfs: don't account buffer cancellation during log recovery readahead
xfs: check for underflow in xfs_iformat_fork()
xfs: xfs_dir3_sfe_put_ino can be static
xfs: introduce object readahead to log recovery
xfs: Simplify xfs_ail_min() with list_first_entry_or_null()
xfs: Register hotcpu notifier after initialization
xfs: add xfs sb v4 support for dirent filetype field
xfs: Add write support for dirent filetype field
xfs: Add read-only support for dirent filetype field
...
Pull timers/nohz changes from Ingo Molnar:
"It mostly contains fixes and full dynticks off-case optimizations, by
Frederic Weisbecker"
* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
nohz: Include local CPU in full dynticks global kick
nohz: Optimize full dynticks's sched hooks with static keys
nohz: Optimize full dynticks state checks with static keys
nohz: Rename a few state variables
vtime: Always debug check snapshot source _before_ updating it
vtime: Always scale generic vtime accounting results
vtime: Optimize full dynticks accounting off case with static keys
vtime: Describe overriden functions in dedicated arch headers
m68k: hardirq_count() only need preempt_mask.h
hardirq: Split preempt count mask definitions
context_tracking: Split low level state headers
vtime: Fix racy cputime delta update
vtime: Remove a few unneeded generic vtime state checks
context_tracking: User/kernel broundary cross trace events
context_tracking: Optimize context switch off case with static keys
context_tracking: Optimize guest APIs off case with static key
context_tracking: Optimize main APIs off case with static key
context_tracking: Ground setup for static key use
context_tracking: Remove full dynticks' hacky dependency on wide context tracking
nohz: Only enable context tracking on full dynticks CPUs
...
Pull RCU updates from Paul E. McKenney:
"
* Update RCU documentation. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/611.
* Miscellaneous fixes. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/619.
* Full-system idle detection. This is for use by Frederic
Weisbecker's adaptive-ticks mechanism. Its purpose is
to allow the timekeeping CPU to shut off its tick when
all other CPUs are idle. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/648.
* Improve rcutorture test coverage. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/675.
"
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The swapaccount kernel parameter without any values has been removed by
commit a2c8990aed ("memsw: remove noswapaccount kernel parameter") but
it seems that we didn't get rid of all the left overs.
Make sure that menuconfig help text and kernel-parameters.txt are clear
about value for the paramter and remove the stalled comment which is not
very much useful on its own.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Gergely Risko <gergely@risko.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
TREE_RCU and TREE_PREEMPT_RCU both cause kernel/rcutree.c to be built,
but only TREE_RCU selects IRQ_WORK, which can result in an undefined
reference to irq_work_queue for some (random) configs:
kernel/built-in.o In function `rcu_start_gp_advanced':
kernel/rcutree.c:1564: undefined reference to `irq_work_queue'
Select IRQ_WORK from TREE_PREEMPT_RCU too to fix this.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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>
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>
Now that the full dynticks subsystem only enables the context tracking
on full dynticks CPUs, lets remove the dependency on CONTEXT_TRACKING_FORCE
This dependency was a hack to enable the context tracking widely for the
full dynticks susbsystem until the latter becomes able to enable it in a
more CPU-finegrained fashion.
Now CONTEXT_TRACKING_FORCE only stands for testing on archs that
work on support for the context tracking while full dynticks can't be
used yet due to unmet dependencies. It simulates a system where all CPUs
are full dynticks so that RCU user extended quiescent states and dynticks
cputime accounting can be tested on the given arch.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
Pull slab update from Pekka Enberg:
"Highlights:
- Fix for boot-time problems on some architectures due to
init_lock_keys() not respecting kmalloc_caches boundaries
(Christoph Lameter)
- CONFIG_SLUB_CPU_PARTIAL requested by RT folks (Joonsoo Kim)
- Fix for excessive slab freelist draining (Wanpeng Li)
- SLUB and SLOB cleanups and fixes (various people)"
I ended up editing the branch, and this avoids two commits at the end
that were immediately reverted, and I instead just applied the oneliner
fix in between myself.
* 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux
slub: Check for page NULL before doing the node_match check
mm/slab: Give s_next and s_stop slab-specific names
slob: Check for NULL pointer before calling ctor()
slub: Make cpu partial slab support configurable
slab: add kmalloc() to kernel API documentation
slab: fix init_lock_keys
slob: use DIV_ROUND_UP where possible
slub: do not put a slab to cpu partial list when cpu_partial is 0
mm/slub: Use node_nr_slabs and node_nr_objs in get_slabinfo
mm/slub: Drop unnecessary nr_partials
mm/slab: Fix /proc/slabinfo unwriteable for slab
mm/slab: Sharing s_next and s_stop between slab and slub
mm/slab: Fix drain freelist excessively
slob: Rework #ifdeffery in slab.h
mm, slab: moved kmem_cache_alloc_node comment to correct place
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>
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>
Pull timer core updates from Thomas Gleixner:
"The timer changes contain:
- posix timer code consolidation and fixes for odd corner cases
- sched_clock implementation moved from ARM to core code to avoid
duplication by other architectures
- alarm timer updates
- clocksource and clockevents unregistration facilities
- clocksource/events support for new hardware
- precise nanoseconds RTC readout (Xen feature)
- generic support for Xen suspend/resume oddities
- the usual lot of fixes and cleanups all over the place
The parts which touch other areas (ARM/XEN) have been coordinated with
the relevant maintainers. Though this results in an handful of
trivial to solve merge conflicts, which we preferred over nasty cross
tree merge dependencies.
The patches which have been committed in the last few days are bug
fixes plus the posix timer lot. The latter was in akpms queue and
next for quite some time; they just got forgotten and Frederic
collected them last minute."
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (59 commits)
hrtimer: Remove unused variable
hrtimers: Move SMP function call to thread context
clocksource: Reselect clocksource when watchdog validated high-res capability
posix-cpu-timers: don't account cpu timer after stopped thread runtime accounting
posix_timers: fix racy timer delta caching on task exit
posix-timers: correctly get dying task time sample in posix_cpu_timer_schedule()
selftests: add basic posix timers selftests
posix_cpu_timers: consolidate expired timers check
posix_cpu_timers: consolidate timer list cleanups
posix_cpu_timer: consolidate expiry time type
tick: Sanitize broadcast control logic
tick: Prevent uncontrolled switch to oneshot mode
tick: Make oneshot broadcast robust vs. CPU offlining
x86: xen: Sync the CMOS RTC as well as the Xen wallclock
x86: xen: Sync the wallclock when the system time is set
timekeeping: Indicate that clock was set in the pvclock gtod notifier
timekeeping: Pass flags instead of multiple bools to timekeeping_update()
xen: Remove clock_was_set() call in the resume path
hrtimers: Support resuming with two or more CPUs online (but stopped)
timer: Fix jiffies wrap behavior of round_jiffies_common()
...
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/core
Frederic sayed: "Most of these patches have been hanging around for
several month now, in -mmotm for a significant chunk. They already
missed a few releases."
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Now there are only 2 members in struct page_cgroup. Update config MEMCG
description accordingly.
Signed-off-by: Sergey Dyasly <dserrg@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
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>
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>
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>
TINY_PREEMPT_RCU adds significant code and complexity, but does not
offer commensurate benefits. People currently using TINY_PREEMPT_RCU
can get much better memory footprint with TINY_RCU, or, if they really
need preemptible RCU, they can use TREE_PREEMPT_RCU with a relatively
minor degradation in memory footprint. Please note that this move
has been widely publicized on LKML (https://lkml.org/lkml/2012/11/12/545)
and on LWN (http://lwn.net/Articles/541037/).
This commit therefore removes TINY_PREEMPT_RCU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Updated to eliminate #else in rcutiny.h as suggested by Josh ]
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The Kconfig help text for the RCU_NOCB_CPU_NONE, RCU_NOCB_CPU_ZERO,
and RCU_NOCB_CPU_ALL Kconfig options was unclear, so this commit
adds a bit more detail.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
After a release or two, features are no longer experimental. Therefore,
this commit removes the "Experimental" tag from them.
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Ever since commit 45f035ab9b ("CONFIG_HOTPLUG should be always on"),
it has been basically impossible to build a kernel with CONFIG_HOTPLUG
turned off. Remove all the remaining references to it.
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull 'full dynticks' support from Ingo Molnar:
"This tree from Frederic Weisbecker adds a new, (exciting! :-) core
kernel feature to the timer and scheduler subsystems: 'full dynticks',
or CONFIG_NO_HZ_FULL=y.
This feature extends the nohz variable-size timer tick feature from
idle to busy CPUs (running at most one task) as well, potentially
reducing the number of timer interrupts significantly.
This feature got motivated by real-time folks and the -rt tree, but
the general utility and motivation of full-dynticks runs wider than
that:
- HPC workloads get faster: CPUs running a single task should be able
to utilize a maximum amount of CPU power. A periodic timer tick at
HZ=1000 can cause a constant overhead of up to 1.0%. This feature
removes that overhead - and speeds up the system by 0.5%-1.0% on
typical distro configs even on modern systems.
- Real-time workload latency reduction: CPUs running critical tasks
should experience as little jitter as possible. The last remaining
source of kernel-related jitter was the periodic timer tick.
- A single task executing on a CPU is a pretty common situation,
especially with an increasing number of cores/CPUs, so this feature
helps desktop and mobile workloads as well.
The cost of the feature is mainly related to increased timer
reprogramming overhead when a CPU switches its tick period, and thus
slightly longer to-idle and from-idle latency.
Configuration-wise a third mode of operation is added to the existing
two NOHZ kconfig modes:
- CONFIG_HZ_PERIODIC: [formerly !CONFIG_NO_HZ], now explicitly named
as a config option. This is the traditional Linux periodic tick
design: there's a HZ tick going on all the time, regardless of
whether a CPU is idle or not.
- CONFIG_NO_HZ_IDLE: [formerly CONFIG_NO_HZ=y], this turns off the
periodic tick when a CPU enters idle mode.
- CONFIG_NO_HZ_FULL: this new mode, in addition to turning off the
tick when a CPU is idle, also slows the tick down to 1 Hz (one
timer interrupt per second) when only a single task is running on a
CPU.
The .config behavior is compatible: existing !CONFIG_NO_HZ and
CONFIG_NO_HZ=y settings get translated to the new values, without the
user having to configure anything. CONFIG_NO_HZ_FULL is turned off by
default.
This feature is based on a lot of infrastructure work that has been
steadily going upstream in the last 2-3 cycles: related RCU support
and non-periodic cputime support in particular is upstream already.
This tree adds the final pieces and activates the feature. The pull
request is marked RFC because:
- it's marked 64-bit only at the moment - the 32-bit support patch is
small but did not get ready in time.
- it has a number of fresh commits that came in after the merge
window. The overwhelming majority of commits are from before the
merge window, but still some aspects of the tree are fresh and so I
marked it RFC.
- it's a pretty wide-reaching feature with lots of effects - and
while the components have been in testing for some time, the full
combination is still not very widely used. That it's default-off
should reduce its regression abilities and obviously there are no
known regressions with CONFIG_NO_HZ_FULL=y enabled either.
- the feature is not completely idempotent: there is no 100%
equivalent replacement for a periodic scheduler/timer tick. In
particular there's ongoing work to map out and reduce its effects
on scheduler load-balancing and statistics. This should not impact
correctness though, there are no known regressions related to this
feature at this point.
- it's a pretty ambitious feature that with time will likely be
enabled by most Linux distros, and we'd like you to make input on
its design/implementation, if you dislike some aspect we missed.
Without flaming us to crisp! :-)
Future plans:
- there's ongoing work to reduce 1Hz to 0Hz, to essentially shut off
the periodic tick altogether when there's a single busy task on a
CPU. We'd first like 1 Hz to be exposed more widely before we go
for the 0 Hz target though.
- once we reach 0 Hz we can remove the periodic tick assumption from
nr_running>=2 as well, by essentially interrupting busy tasks only
as frequently as the sched_latency constraints require us to do -
once every 4-40 msecs, depending on nr_running.
I am personally leaning towards biting the bullet and doing this in
v3.10, like the -rt tree this effort has been going on for too long -
but the final word is up to you as usual.
More technical details can be found in Documentation/timers/NO_HZ.txt"
* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
sched: Keep at least 1 tick per second for active dynticks tasks
rcu: Fix full dynticks' dependency on wide RCU nocb mode
nohz: Protect smp_processor_id() in tick_nohz_task_switch()
nohz_full: Add documentation.
cputime_nsecs: use math64.h for nsec resolution conversion helpers
nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config
nohz: Reduce overhead under high-freq idling patterns
nohz: Remove full dynticks' superfluous dependency on RCU tree
nohz: Fix unavailable tick_stop tracepoint in dynticks idle
nohz: Add basic tracing
nohz: Select wide RCU nocb for full dynticks
nohz: Disable the tick when irq resume in full dynticks CPU
nohz: Re-evaluate the tick for the new task after a context switch
nohz: Prepare to stop the tick on irq exit
nohz: Implement full dynticks kick
nohz: Re-evaluate the tick from the scheduler IPI
sched: New helper to prevent from stopping the tick in full dynticks
sched: Kick full dynticks CPU that have more than one task enqueued.
perf: New helper to prevent full dynticks CPUs from stopping tick
perf: Kick full dynticks CPU if events rotation is needed
...
Commit 0637e02939
("nohz: Select wide RCU nocb for full dynticks") intended
to force CONFIG_RCU_NOCB_CPU_ALL=y when full dynticks is
enabled.
However this option is part of a choice menu and Kconfig's
"select" instruction has no effect on such targets.
Fix this by using reverse dependencies on the targets we
don't want instead.
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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 Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
The full dynticks tree needs the latest RCU and sched
upstream updates in order to fix some dependencies.
Merge a common upstream merge point that has these
updates.
Conflicts:
include/linux/perf_event.h
kernel/rcutree.h
kernel/rcutree_plugin.h
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
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>
Pull scheduler changes from Ingo Molnar:
"The main changes in this development cycle were:
- full dynticks preparatory work by Frederic Weisbecker
- factor out the cpu time accounting code better, by Li Zefan
- multi-CPU load balancer cleanups and improvements by Joonsoo Kim
- various smaller fixes and cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
sched: Fix init NOHZ_IDLE flag
sched: Prevent to re-select dst-cpu in load_balance()
sched: Rename load_balance_tmpmask to load_balance_mask
sched: Move up affinity check to mitigate useless redoing overhead
sched: Don't consider other cpus in our group in case of NEWLY_IDLE
sched: Explicitly cpu_idle_type checking in rebalance_domains()
sched: Change position of resched_cpu() in load_balance()
sched: Fix wrong rq's runnable_avg update with rt tasks
sched: Document task_struct::personality field
sched/cpuacct/UML: Fix header file dependency bug on the UML build
cgroup: Kill subsys.active flag
sched/cpuacct: No need to check subsys active state
sched/cpuacct: Initialize cpuacct subsystem earlier
sched/cpuacct: Initialize root cpuacct earlier
sched/cpuacct: Allocate per_cpu cpuusage for root cpuacct statically
sched/cpuacct: Clean up cpuacct.h
sched/cpuacct: Remove redundant NULL checks in cpuacct_acount_field()
sched/cpuacct: Remove redundant NULL checks in cpuacct_charge()
sched/cpuacct: Add cpuacct_acount_field()
sched/cpuacct: Add cpuacct_init()
...
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>
Pull RCU updates from Paul E. McKenney:
* Remove restrictions on no-CBs CPUs, make RCU_FAST_NO_HZ
take advantage of numbered callbacks, do additional callback
accelerations based on numbered callbacks. Posted to LKML
at https://lkml.org/lkml/2013/3/18/960.
* RCU documentation updates. Posted to LKML at
https://lkml.org/lkml/2013/3/18/570.
* Miscellaneous fixes. Posted to LKML at
https://lkml.org/lkml/2013/3/18/594.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are planning to convert the dynticks Kconfig options layout
into a choice menu. The user must be able to easily pick
any of the following implementations: constant periodic tick,
idle dynticks, full dynticks.
As this implies a mutual exclusion, the two dynticks implementions
need to converge on the selection of a common Kconfig option in order
to ease the sharing of a common infrastructure.
It would thus seem pretty natural to reuse CONFIG_NO_HZ to
that end. It already implements all the idle dynticks code
and the full dynticks depends on all that code for now.
So ideally the choice menu would propose CONFIG_NO_HZ_IDLE and
CONFIG_NO_HZ_EXTENDED then both would select CONFIG_NO_HZ.
On the other hand we want to stay backward compatible: if
CONFIG_NO_HZ is set in an older config file, we want to
enable CONFIG_NO_HZ_IDLE by default.
But we can't afford both at the same time or we run into
a circular dependency:
1) CONFIG_NO_HZ_IDLE and CONFIG_NO_HZ_EXTENDED both select
CONFIG_NO_HZ
2) If CONFIG_NO_HZ is set, we default to CONFIG_NO_HZ_IDLE
We might be able to support that from Kconfig/Kbuild but it
may not be wise to introduce such a confusing behaviour.
So to solve this, create a new CONFIG_NO_HZ_COMMON option
which gathers the common code between idle and full dynticks
(that common code for now is simply the idle dynticks code)
and select it from their referring Kconfig.
Then we'll later create CONFIG_NO_HZ_IDLE and map CONFIG_NO_HZ
to it for backward compatibility.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.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: 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>
Because RCU callbacks are now associated with the number of the grace
period that they must wait for, CPUs can now take advance callbacks
corresponding to grace periods that ended while a given CPU was in
dyntick-idle mode. This eliminates the need to try forcing the RCU
state machine while entering idle, thus reducing the CPU intensiveness
of RCU_FAST_NO_HZ, which should increase its energy efficiency.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Currently, the per-no-CBs-CPU kthreads are named "rcuo" followed by
the CPU number, for example, "rcuo". This is problematic given that
there are either two or three RCU flavors, each of which gets a per-CPU
kthread with exactly the same name. This commit therefore introduces
a one-letter abbreviation for each RCU flavor, namely 'b' for RCU-bh,
'p' for RCU-preempt, and 's' for RCU-sched. This abbreviation is used
to distinguish the "rcuo" kthreads, for example, for CPU 0 we would have
"rcuob/0", "rcuop/0", and "rcuos/0".
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Currently, the only way to specify no-CBs CPUs is via the rcu_nocbs
kernel command-line parameter. This is inconvenient in some cases,
particularly for randconfig testing, so this commit adds a new set of
kernel configuration parameters. CONFIG_RCU_NOCB_CPU_NONE (the default)
retains the old behavior, CONFIG_RCU_NOCB_CPU_ZERO offloads callback
processing from CPU 0 (along with any other CPUs specified by the
rcu_nocbs boot-time parameter), and CONFIG_RCU_NOCB_CPU_ALL offloads
callback processing from all CPUs.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Remove "config EXPERIMENTAL" itself, now that every "depends on" it has
been removed from the tree.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, CPU 0 is constrained to not be a no-CBs CPU, and furthermore
at least one no-CBs CPU must remain online at any given time. These
restrictions are problematic in some situations, such as cases where
all CPUs must run a real-time workload that needs to be insulated from
OS jitter and latencies due to RCU callback invocation. This commit
therefore provides no-CBs CPUs a (very crude and energy-inefficient)
way to start and to wait for grace periods independently of the normal
RCU callback mechanisms. This approach allows any or all of the CPUs to
be designated as no-CBs CPUs, and allows any proper subset of the CPUs
(whether no-CBs CPUs or not) to be offlined.
This commit also provides a fix for a locking bug spotted by Xie
ChanglongX <changlongx.xie@intel.com>.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Until we provide the nohz_mask boot parameter, keeping
the context tracking probes disabled by default is pointless
since what we want is to runtime test this code anyway.
It's furthermore confusing for the users which don't expect
the probes to be off when they select RCU user mode or full
dynticks cputime accounting.
Let's enable these probes selftests by default for now.
Suggested: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Mats Liljegren <mats.liljegren@enea.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Merge tag 'arc-v3.9-rc1-late' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull new ARC architecture from Vineet Gupta:
"Initial ARC Linux port with some fixes on top for 3.9-rc1:
I would like to introduce the Linux port to ARC Processors (from
Synopsys) for 3.9-rc1. The patch-set has been discussed on the public
lists since Nov and has received a fair bit of review, specially from
Arnd, tglx, Al and other subsystem maintainers for DeviceTree, kgdb...
The arch bits are in arch/arc, some asm-generic changes (acked by
Arnd), a minor change to PARISC (acked by Helge).
The series is a touch bigger for a new port for 2 main reasons:
1. It enables a basic kernel in first sub-series and adds
ptrace/kgdb/.. later
2. Some of the fallout of review (DeviceTree support, multi-platform-
image support) were added on top of orig series, primarily to
record the revision history.
This updated pull request additionally contains
- fixes due to our GNU tools catching up with the new syscall/ptrace
ABI
- some (minor) cross-arch Kconfig updates."
* tag 'arc-v3.9-rc1-late' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (82 commits)
ARC: split elf.h into uapi and export it for userspace
ARC: Fixup the current ABI version
ARC: gdbserver using regset interface possibly broken
ARC: Kconfig cleanup tracking cross-arch Kconfig pruning in merge window
ARC: make a copy of flat DT
ARC: [plat-arcfpga] DT arc-uart bindings change: "baud" => "current-speed"
ARC: Ensure CONFIG_VIRT_TO_BUS is not enabled
ARC: Fix pt_orig_r8 access
ARC: [3.9] Fallout of hlist iterator update
ARC: 64bit RTSC timestamp hardware issue
ARC: Don't fiddle with non-existent caches
ARC: Add self to MAINTAINERS
ARC: Provide a default serial.h for uart drivers needing BASE_BAUD
ARC: [plat-arcfpga] defconfig for fully loaded ARC Linux
ARC: [Review] Multi-platform image #8: platform registers SMP callbacks
ARC: [Review] Multi-platform image #7: SMP common code to use callbacks
ARC: [Review] Multi-platform image #6: cpu-to-dma-addr optional
ARC: [Review] Multi-platform image #5: NR_IRQS defined by ARC core
ARC: [Review] Multi-platform image #4: Isolate platform headers
ARC: [Review] Multi-platform image #3: switch to board callback
...
Pull user namespace and namespace infrastructure changes from Eric W Biederman:
"This set of changes starts with a few small enhnacements to the user
namespace. reboot support, allowing more arbitrary mappings, and
support for mounting devpts, ramfs, tmpfs, and mqueuefs as just the
user namespace root.
I do my best to document that if you care about limiting your
unprivileged users that when you have the user namespace support
enabled you will need to enable memory control groups.
There is a minor bug fix to prevent overflowing the stack if someone
creates way too many user namespaces.
The bulk of the changes are a continuation of the kuid/kgid push down
work through the filesystems. These changes make using uids and gids
typesafe which ensures that these filesystems are safe to use when
multiple user namespaces are in use. The filesystems converted for
3.9 are ceph, 9p, afs, ocfs2, gfs2, ncpfs, nfs, nfsd, and cifs. The
changes for these filesystems were a little more involved so I split
the changes into smaller hopefully obviously correct changes.
XFS is the only filesystem that remains. I was hoping I could get
that in this release so that user namespace support would be enabled
with an allyesconfig or an allmodconfig but it looks like the xfs
changes need another couple of days before it they are ready."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (93 commits)
cifs: Enable building with user namespaces enabled.
cifs: Convert struct cifs_ses to use a kuid_t and a kgid_t
cifs: Convert struct cifs_sb_info to use kuids and kgids
cifs: Modify struct smb_vol to use kuids and kgids
cifs: Convert struct cifsFileInfo to use a kuid
cifs: Convert struct cifs_fattr to use kuid and kgids
cifs: Convert struct tcon_link to use a kuid.
cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t
cifs: Convert from a kuid before printing current_fsuid
cifs: Use kuids and kgids SID to uid/gid mapping
cifs: Pass GLOBAL_ROOT_UID and GLOBAL_ROOT_GID to keyring_alloc
cifs: Use BUILD_BUG_ON to validate uids and gids are the same size
cifs: Override unmappable incoming uids and gids
nfsd: Enable building with user namespaces enabled.
nfsd: Properly compare and initialize kuids and kgids
nfsd: Store ex_anon_uid and ex_anon_gid as kuids and kgids
nfsd: Modify nfsd4_cb_sec to use kuids and kgids
nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion
nfsd: Convert nfsxdr to use kuids and kgids
nfsd: Convert nfs3xdr to use kuids and kgids
...
lockdep, but it's a mechanical change.
Cheers,
Rusty.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module update from Rusty Russell:
"The sweeping change is to make add_taint() explicitly indicate whether
to disable lockdep, but it's a mechanical change."
* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
MODSIGN: Add option to not sign modules during modules_install
MODSIGN: Add -s <signature> option to sign-file
MODSIGN: Specify the hash algorithm on sign-file command line
MODSIGN: Simplify Makefile with a Kconfig helper
module: clean up load_module a little more.
modpost: Ignore ARC specific non-alloc sections
module: constify within_module_*
taint: add explicit flag to show whether lock dep is still OK.
module: printk message when module signature fail taints kernel.
Here is the big driver core merge for 3.9-rc1
There are two major series here, both of which touch lots of drivers all
over the kernel, and will cause you some merge conflicts:
- add a new function called devm_ioremap_resource() to properly be
able to check return values.
- remove CONFIG_EXPERIMENTAL
If you need me to provide a merged tree to handle these resolutions,
please let me know.
Other than those patches, there's not much here, some minor fixes and
updates.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core patches from Greg Kroah-Hartman:
"Here is the big driver core merge for 3.9-rc1
There are two major series here, both of which touch lots of drivers
all over the kernel, and will cause you some merge conflicts:
- add a new function called devm_ioremap_resource() to properly be
able to check return values.
- remove CONFIG_EXPERIMENTAL
Other than those patches, there's not much here, some minor fixes and
updates"
Fix up trivial conflicts
* tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (221 commits)
base: memory: fix soft/hard_offline_page permissions
drivercore: Fix ordering between deferred_probe and exiting initcalls
backlight: fix class_find_device() arguments
TTY: mark tty_get_device call with the proper const values
driver-core: constify data for class_find_device()
firmware: Ignore abort check when no user-helper is used
firmware: Reduce ifdef CONFIG_FW_LOADER_USER_HELPER
firmware: Make user-mode helper optional
firmware: Refactoring for splitting user-mode helper code
Driver core: treat unregistered bus_types as having no devices
watchdog: Convert to devm_ioremap_resource()
thermal: Convert to devm_ioremap_resource()
spi: Convert to devm_ioremap_resource()
power: Convert to devm_ioremap_resource()
mtd: Convert to devm_ioremap_resource()
mmc: Convert to devm_ioremap_resource()
mfd: Convert to devm_ioremap_resource()
media: Convert to devm_ioremap_resource()
iommu: Convert to devm_ioremap_resource()
drm: Convert to devm_ioremap_resource()
...
Pull scheduler changes from Ingo Molnar:
"Main changes:
- scheduler side full-dynticks (user-space execution is undisturbed
and receives no timer IRQs) preparation changes that convert the
cputime accounting code to be full-dynticks ready, from Frederic
Weisbecker.
- Initial sched.h split-up changes, by Clark Williams
- select_idle_sibling() performance improvement by Mike Galbraith:
" 1 tbench pair (worst case) in a 10 core + SMT package:
pre 15.22 MB/sec 1 procs
post 252.01 MB/sec 1 procs "
- sched_rr_get_interval() ABI fix/change. We think this detail is not
used by apps (so it's not an ABI in practice), but lets keep it
under observation.
- misc RT scheduling cleanups, optimizations"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
sched/rt: Add <linux/sched/rt.h> header to <linux/init_task.h>
cputime: Remove irqsave from seqlock readers
sched, powerpc: Fix sched.h split-up build failure
cputime: Restore CPU_ACCOUNTING config defaults for PPC64
sched/rt: Move rt specific bits into new header file
sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice
sched: Move sched.h sysctl bits into separate header
sched: Fix signedness bug in yield_to()
sched: Fix select_idle_sibling() bouncing cow syndrome
sched/rt: Further simplify pick_rt_task()
sched/rt: Do not account zero delta_exec in update_curr_rt()
cputime: Safely read cputime of full dynticks CPUs
kvm: Prepare to add generic guest entry/exit callbacks
cputime: Use accessors to read task cputime stats
cputime: Allow dynamic switch between tick/virtual based cputime accounting
cputime: Generic on-demand virtual cputime accounting
cputime: Move default nsecs_to_cputime() to jiffies based cputime file
cputime: Librarize per nsecs resolution cputime definitions
cputime: Avoid multiplication overflow on utime scaling
context_tracking: Export context state for generic vtime
...
Fix up conflict in kernel/context_tracking.c due to comment additions.
Pull irq core changes from Ingo Molnar:
"The biggest changes are the IRQ-work and printk changes from Frederic
Weisbecker, which prepare the code for 'full dynticks' (the ability to
stop or slow down the periodic tick arbitrarily, not just in idle time
as today):
- Don't stop tick with irq works pending. This fix is generally
useful and concerns archs that can't raise self IPIs.
- Flush irq works before CPU offlining.
- Introduce "lazy" irq works that can wait for the next tick to be
executed, unless it's stopped.
- Implement klogd wake up using irq work. This removes the ad-hoc
printk_tick()/printk_needs_cpu() hooks and make it working even in
dynticks mode.
- Cleanups and fixes."
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Export enable/disable_percpu_irq()
arch Kconfig: Remove references to IRQ_PER_CPU
irq_work: Remove return value from the irq_work_queue() function
genirq: Avoid deadlock in spurious handling
printk: Wake up klogd using irq_work
irq_work: Make self-IPIs optable
irq_work: Warn if there's still work on cpu_down
irq_work: Flush work on CPU_DYING
irq_work: Don't stop the tick with pending works
nohz: Add API to check tick state
irq_work: Remove CONFIG_HAVE_IRQ_WORK
irq_work: Fix racy check on work pending flag
irq_work: Fix racy IRQ_WORK_BUSY flag setting
PARISC defines /proc/sys/kernel/unaligned-trap to runtime toggle
unaligned access emulation.
The exact mechanics of enablig/disabling are still arch specific, we can
make the sysctl usable by other arches.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Now that the kuids and kgids conversion have propogated
through net/sunrpc/ and the fs/nfsd/ it is safe to enable
building nfsd when user namespaces are enabled.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Now that the kuids and kgids conversion have propogated
through net/sunrpc/ and the fs/nfs/ it is safe to enable
building nfs when user namespaces are enabled.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
ncpfs does not natively support uids and gids so this conversion was
simply a matter of updating the the type of the mounteduid, the uid
and the gid on the superblock. Fixing the ioctls that read them,
updating the mount option parser and the mount option printer.
Cc: Petr Vandrovec <petr@vandrovec.name>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Now that all of the necessary work has been done to push kuids and
kgids throughout gfs2 and to convert between kuids and kgids when
reading and writing the on disk structures it is safe to enable gfs2
when multiple user namespaces are enabled.
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Now that ocfs2 has been converted to store uids and gids in
kuid_t and kgid_t and all of the conversions have been added
to the appropriate places it is safe to allow building and
using ocfs2 with user namespace support enabled.
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Now that the coda kernel to userspace has been modified to convert
between kuids and kgids and uids and gids, and all internal
coda structures have be modified to store uids and gids as
kuids and kgids it is safe to allow code to be built with
user namespace support enabled.
Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Modify struct afs_file_status to store owner as a kuid_t and group as
a kgid_t.
In xdr_decode_AFSFetchStatus as owner is now a kuid_t and group is now
a kgid_t don't use the EXTRACT macro. Instead perform the work of
the extract macro explicitly. Read the value with ntohl and
convert it to the appropriate type with make_kuid or make_kgid.
Test if the value is different from what is stored in status and
update changed. Update the value in status.
In xdr_encode_AFS_StoreStatus call from_kuid or from_kgid as
we are computing the on the wire encoding.
Initialize uids with GLOBAL_ROOT_UID instead of 0.
Initialize gids with GLOBAL_ROOT_GID instead of 0.
Cc: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Now that the uid_t -> kuid_t, gid_t -> kgid_t conversion
has been completed in 9p allow 9p to be built when user
namespaces are enabled.
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Now that conversions happen from kuids and kgids when generating ceph
messages and conversion happen to kuids and kgids after receiving
celph messages, and all intermediate data structures store uids and
gids as type kuid_t and kgid_t it is safe to enable ceph with
user namespace support enabled.
Cc: Sage Weil <sage@inktank.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Conflicts:
kernel/irq_work.c
Add support for printk in full dynticks CPU.
* Don't stop tick with irq works pending. This
fix is generally useful and concerns archs that
can't raise self IPIs.
* Flush irq works before CPU offlining.
* Introduce "lazy" irq works that can wait for the
next tick to be executed, unless it's stopped.
* Implement klogd wake up using irq work. This
removes the ad-hoc printk_tick()/printk_needs_cpu()
hooks and make it working even in dynticks mode.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
The TINY_PREEMPT_RCU is complex, does not provide that much memory
savings, and therefore TREE_PREEMPT_RCU should be used instead. The
systems where the difference between TINY_PREEMPT_RCU and TREE_PREEMPT_RCU
are quite small compared to the memory footprint of CONFIG_PREEMPT.
This commit therefore takes a first step towards eliminating
TINY_PREEMPT_RCU by allowing TREE_PREEMPT_RCU to be configured on !SMP
systems.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tiny RCU has historically omitted RCU CPU stall warnings in order to
reduce memory requirements, however, lack of these warnings caused
Thomas Gleixner some debugging pain recently. Therefore, this commit
adds RCU CPU stall warnings to tiny RCU if RCU_TRACE=y. This keeps
the memory footprint small, while still enabling CPU stall warnings
in kernels built to enable them.
Updated to include Josh Triplett's suggested use of RCU_STALL_COMMON
config variable to simplify #if expressions.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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>
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>
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>
This is to fix up a build problem with a wireless driver due to the
dynamic-debug patches in this branch.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit 281dc5c5ec ("Give up on pushing CC_OPTIMIZE_FOR_SIZE") we
already changed the actual default value, but the help-text still
suggested 'y'. Fix the help text too, for all the same reasons.
Sadly, -Os keeps on generating some very suboptimal code for certain
cases, to the point where any I$ miss upside is swamped by the downside.
The main ones are:
- using "rep movsb" for memcpy, even on CPU's where that is
horrendously bad for performance.
- not honoring branch prediction information, so any I$ footprint you
win from smaller code, you lose from less code density in the I$.
- using divide instructions when that is very expensive.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
This config item has not carried much meaning for a while now and is
almost always enabled by default (especially in distro builds). As agreed
during the Linux kernel summit, it should be removed. As a first step,
remove it from being listed, and default it to on. Once it has been
removed from all subsystem Kconfigs, it will be dropped entirely.
For items that really are experimental, maintainers should use "default
n", optionally include "(EXPERIMENTAL)" in the title, and add language to
the help text indicating why the item should be considered experimental.
For items that are dangerously experimental, the maintainer is encouraged
to follow the above title recommendation, add stronger language to the
help text, and optionally use (depending on the extent of the danger,
from least to most dangerous): printk(), add_taint(TAINT_WARN),
add_taint(TAINT_CRAP), WARN_ON(1), and CONFIG_BROKEN.
CC: Greg KH <gregkh@linuxfoundation.org>
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@canonical.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
IA64 defines /proc/sys/kernel/ignore-unaligned-usertrap to control
verbose warnings on unaligned access emulation.
Although the exact mechanics of what to do with sysctl (ignore/shout)
are arch specific, this change enables the sysctl to be usable cross-arch.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The page allocator is able to bind a page to a memcg when it is
allocated. But for the caches, we'd like to have as many objects as
possible in a page belonging to the same cache.
This is done in this patch by calling memcg_kmem_get_cache in the
beginning of every allocation function. This function is patched out by
static branches when kernel memory controller is not being used.
It assumes that the task allocating, which determines the memcg in the
page allocator, belongs to the same cgroup throughout the whole process.
Misaccounting can happen if the task calls memcg_kmem_get_cache() while
belonging to a cgroup, and later on changes. This is considered
acceptable, and should only happen upon task migration.
Before the cache is created by the memcg core, there is also a possible
imbalance: the task belongs to a memcg, but the cache being allocated from
is the global cache, since the child cache is not yet guaranteed to be
ready. This case is also fine, since in this case the GFP_KMEMCG will not
be passed and the page allocator will not attempt any cgroup accounting.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add the basic infrastructure for the accounting of kernel memory. To
control that, the following files are created:
* memory.kmem.usage_in_bytes
* memory.kmem.limit_in_bytes
* memory.kmem.failcnt
* memory.kmem.max_usage_in_bytes
They have the same meaning of their user memory counterparts. They
reflect the state of the "kmem" res_counter.
Per cgroup kmem memory accounting is not enabled until a limit is set for
the group. Once the limit is set the accounting cannot be disabled for
that group. This means that after the patch is applied, no behavioral
changes exists for whoever is still using memcg to control their memory
usage, until memory.kmem.limit_in_bytes is set for the first time.
We always account to both user and kernel resource_counters. This
effectively means that an independent kernel limit is in place when the
limit is set to a lower value than the user memory. A equal or higher
value means that the user limit will always hit first, meaning that kmem
is effectively unlimited.
People who want to track kernel memory but not limit it, can set this
limit to a very high number (like RESOURCE_MAX - 1page - that no one will
ever hit, or equal to the user memory)
[akpm@linux-foundation.org: MEMCG_MMEM only works with slab and slub]
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull user namespace changes from Eric Biederman:
"While small this set of changes is very significant with respect to
containers in general and user namespaces in particular. The user
space interface is now complete.
This set of changes adds support for unprivileged users to create user
namespaces and as a user namespace root to create other namespaces.
The tyranny of supporting suid root preventing unprivileged users from
using cool new kernel features is broken.
This set of changes completes the work on setns, adding support for
the pid, user, mount namespaces.
This set of changes includes a bunch of basic pid namespace
cleanups/simplifications. Of particular significance is the rework of
the pid namespace cleanup so it no longer requires sending out
tendrils into all kinds of unexpected cleanup paths for operation. At
least one case of broken error handling is fixed by this cleanup.
The files under /proc/<pid>/ns/ have been converted from regular files
to magic symlinks which prevents incorrect caching by the VFS,
ensuring the files always refer to the namespace the process is
currently using and ensuring that the ptrace_mayaccess permission
checks are always applied.
The files under /proc/<pid>/ns/ have been given stable inode numbers
so it is now possible to see if different processes share the same
namespaces.
Through the David Miller's net tree are changes to relax many of the
permission checks in the networking stack to allowing the user
namespace root to usefully use the networking stack. Similar changes
for the mount namespace and the pid namespace are coming through my
tree.
Two small changes to add user namespace support were commited here adn
in David Miller's -net tree so that I could complete the work on the
/proc/<pid>/ns/ files in this tree.
Work remains to make it safe to build user namespaces and 9p, afs,
ceph, cifs, coda, gfs2, ncpfs, nfs, nfsd, ocfs2, and xfs so the
Kconfig guard remains in place preventing that user namespaces from
being built when any of those filesystems are enabled.
Future design work remains to allow root users outside of the initial
user namespace to mount more than just /proc and /sys."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (38 commits)
proc: Usable inode numbers for the namespace file descriptors.
proc: Fix the namespace inode permission checks.
proc: Generalize proc inode allocation
userns: Allow unprivilged mounts of proc and sysfs
userns: For /proc/self/{uid,gid}_map derive the lower userns from the struct file
procfs: Print task uids and gids in the userns that opened the proc file
userns: Implement unshare of the user namespace
userns: Implent proc namespace operations
userns: Kill task_user_ns
userns: Make create_new_namespaces take a user_ns parameter
userns: Allow unprivileged use of setns.
userns: Allow unprivileged users to create new namespaces
userns: Allow setting a userns mapping to your current uid.
userns: Allow chown and setgid preservation
userns: Allow unprivileged users to create user namespaces.
userns: Ignore suid and sgid on binaries if the uid or gid can not be mapped
userns: fix return value on mntns_install() failure
vfs: Allow unprivileged manipulation of the mount namespace.
vfs: Only support slave subtrees across different user namespaces
vfs: Add a user namespace reference from struct mnt_namespace
...
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Merge tag 'balancenuma-v11' of git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux-balancenuma
Pull Automatic NUMA Balancing bare-bones from Mel Gorman:
"There are three implementations for NUMA balancing, this tree
(balancenuma), numacore which has been developed in tip/master and
autonuma which is in aa.git.
In almost all respects balancenuma is the dumbest of the three because
its main impact is on the VM side with no attempt to be smart about
scheduling. In the interest of getting the ball rolling, it would be
desirable to see this much merged for 3.8 with the view to building
scheduler smarts on top and adapting the VM where required for 3.9.
The most recent set of comparisons available from different people are
mel: https://lkml.org/lkml/2012/12/9/108
mingo: https://lkml.org/lkml/2012/12/7/331
tglx: https://lkml.org/lkml/2012/12/10/437
srikar: https://lkml.org/lkml/2012/12/10/397
The results are a mixed bag. In my own tests, balancenuma does
reasonably well. It's dumb as rocks and does not regress against
mainline. On the other hand, Ingo's tests shows that balancenuma is
incapable of converging for this workloads driven by perf which is bad
but is potentially explained by the lack of scheduler smarts. Thomas'
results show balancenuma improves on mainline but falls far short of
numacore or autonuma. Srikar's results indicate we all suffer on a
large machine with imbalanced node sizes.
My own testing showed that recent numacore results have improved
dramatically, particularly in the last week but not universally.
We've butted heads heavily on system CPU usage and high levels of
migration even when it shows that overall performance is better.
There are also cases where it regresses. Of interest is that for
specjbb in some configurations it will regress for lower numbers of
warehouses and show gains for higher numbers which is not reported by
the tool by default and sometimes missed in treports. Recently I
reported for numacore that the JVM was crashing with
NullPointerExceptions but currently it's unclear what the source of
this problem is. Initially I thought it was in how numacore batch
handles PTEs but I'm no longer think this is the case. It's possible
numacore is just able to trigger it due to higher rates of migration.
These reports were quite late in the cycle so I/we would like to start
with this tree as it contains much of the code we can agree on and has
not changed significantly over the last 2-3 weeks."
* tag 'balancenuma-v11' of git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux-balancenuma: (50 commits)
mm/rmap, migration: Make rmap_walk_anon() and try_to_unmap_anon() more scalable
mm/rmap: Convert the struct anon_vma::mutex to an rwsem
mm: migrate: Account a transhuge page properly when rate limiting
mm: numa: Account for failed allocations and isolations as migration failures
mm: numa: Add THP migration for the NUMA working set scanning fault case build fix
mm: numa: Add THP migration for the NUMA working set scanning fault case.
mm: sched: numa: Delay PTE scanning until a task is scheduled on a new node
mm: sched: numa: Control enabling and disabling of NUMA balancing if !SCHED_DEBUG
mm: sched: numa: Control enabling and disabling of NUMA balancing
mm: sched: Adapt the scanning rate if a NUMA hinting fault does not migrate
mm: numa: Use a two-stage filter to restrict pages being migrated for unlikely task<->node relationships
mm: numa: migrate: Set last_nid on newly allocated page
mm: numa: split_huge_page: Transfer last_nid on tail page
mm: numa: Introduce last_nid to the page frame
sched: numa: Slowly increase the scanning period as NUMA faults are handled
mm: numa: Rate limit setting of pte_numa if node is saturated
mm: numa: Rate limit the amount of memory that is migrated between nodes
mm: numa: Structures for Migrate On Fault per NUMA migration rate limiting
mm: numa: Migrate pages handled during a pmd_numa hinting fault
mm: numa: Migrate on reference policy
...
This patch adds Kconfig options and kernel parameters to allow the
enabling and disabling of automatic NUMA balancing. The existance
of such a switch was and is very important when debugging problems
related to transparent hugepages and we should have the same for
automatic NUMA placement.
Signed-off-by: Mel Gorman <mgorman@suse.de>
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>
Create a new subsystem that probes on kernel boundaries
to keep track of the transitions between level contexts
with two basic initial contexts: user or kernel.
This is an abstraction of some RCU code that use such tracking
to implement its userspace extended quiescent state.
We need to pull this up from RCU into this new level of indirection
because this tracking is also going to be used to implement an "on
demand" generic virtual cputime accounting. A necessary step to
shutdown the tick while still accounting the cputime.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
[ paulmck: fix whitespace error and email address. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>
irq work can run on any arch even without IPI
support because of the hook on update_process_times().
So lets remove HAVE_IRQ_WORK because it doesn't reflect
any backend requirement.
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>
RCU callback execution can add significant OS jitter and also can
degrade both scheduling latency and, in asymmetric multiprocessors,
energy efficiency. This commit therefore adds the ability for selected
CPUs ("rcu_nocbs=" boot parameter) to have their callbacks offloaded
to kthreads. If the "rcu_nocb_poll" boot parameter is also specified,
these kthreads will do polling, removing the need for the offloaded
CPUs to do wakeups. At least one CPU must be doing normal callback
processing: currently CPU 0 cannot be selected as a no-CBs CPU.
In addition, attempts to offline the last normal-CBs CPU will fail.
This feature was inspired by Jim Houston's and Joe Korty's JRCU, and
this commit includes fixes to problems located by Fengguang Wu's
kbuild test robot.
[ paulmck: Added gfp.h include file as suggested by Fengguang Wu. ]
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Use kuid_t and kgid_t in struct fuse_conn and struct fuse_mount_data.
The connection between between a fuse filesystem and a fuse daemon is
established when a fuse filesystem is mounted and provided with a file
descriptor the fuse daemon created by opening /dev/fuse.
For now restrict the communication of uids and gids between the fuse
filesystem and the fuse daemon to the initial user namespace. Enforce
this by verifying the file descriptor passed to the mount of fuse was
opened in the initial user namespace. Ensuring the mount happens in
the initial user namespace is not necessary as mounts from non-initial
user namespaces are not yet allowed.
In fuse_req_init_context convert the currrent fsuid and fsgid into the
initial user namespace for the request that will be sent to the fuse
daemon.
In fuse_fill_attr convert the uid and gid passed from the fuse daemon
from the initial user namespace into kuids and kgids.
In iattr_to_fattr called from fuse_setattr convert kuids and kgids
into the uids and gids in the initial user namespace before passing
them to the fuse filesystem.
In fuse_change_attributes_common called from fuse_dentry_revalidate,
fuse_permission, fuse_geattr, and fuse_setattr, and fuse_iget convert
the uid and gid from the fuse daemon into a kuid and a kgid to store
on the fuse inode.
By default fuse mounts are restricted to task whose uid, suid, and
euid matches the fuse user_id and whose gid, sgid, and egid matches
the fuse group id. Convert the user_id and group_id mount options
into kuids and kgids at mount time, and use uid_eq and gid_eq to
compare the in fuse_allow_task.
Cc: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Andy Lutomirski