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Arnaldo Carvalho de Melo 1da7e00227 perf beauty waitid options: Fix up prefix showing logic
When introducing the possibility for selecting if the common prefix to
options such as the waitid ones, i.e. all 'waitid' options start with
'W', so, to make it make it more compact if configured to suppress it,
'perf trace' will do so, other examples include mmap's PROT_ prefix for
its 'prot' argument, etc, which, when showing the syscall argument name
ends up producing duplicated info that clutters the screen, i.e.:

  # perf trace -e mmap --max-events 2 sleep 1
     0.000 ( 0.014 ms): sleep/20886 mmap(len: 112595, prot: PROT_READ, flags: MAP_PRIVATE, fd: 3) = 0x7f3e986d2000
     0.041 ( 0.005 ms): sleep/20886 mmap(len: 8192, prot: PROT_READ|PROT_WRITE, flags: MAP_PRIVATE|MAP_ANONYMOUS) = 0x7f3e986d0000
  #

So it is possible to suppress that and make it more compact by having
this in your ~/.perfconfig:

  # cat ~/.perfconfig
  [trace]
	show_prefix = no
  #

  # perf trace -e mmap --max-events 2 sleep 1
     0.000 ( 0.014 ms): sleep/8009 mmap(len: 112595, prot: READ, flags: PRIVATE, fd: 3) = 0x7ff2373de000
     0.040 ( 0.005 ms): sleep/8009 mmap(len: 8192, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS) = 0x7ff2373dc000
  #

To have it look more like strace's output, we instead want to suppress
the arg name and show the prefix, so use:

  # cat ~/.perfconfig
  [trace]
	show_prefix = yes
	show_arg_names = no
  #
  # perf trace -e mmap --max-events 2 sleep 1
     0.000 ( 0.006 ms): sleep/15513 mmap(NULL, 112595, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f7a9b6d3000
     0.020 ( 0.002 ms): sleep/15513 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS) = 0x7f7a9b6d1000
  #

When this logic was introduced a bug came with it when processing the
waitid 'option' arg that ended up expecting 3 strings when just two were
being provided, fix it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: c65c83ffe9 ("perf trace: Allow asking for not suppressing common string prefixes")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-02-14 13:31:12 -03:00
Documentation Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-03 09:08:12 -08:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
arch perf/x86/intel: Add counter freezing quirk for Goldmont 2019-02-11 08:00:42 +01:00
block blk-mq: fix a hung issue when fsync 2019-01-30 08:53:54 -07:00
certs kbuild: remove redundant target cleaning on failure 2019-01-06 09:46:51 +09:00
crypto crypto: sm3 - fix undefined shift by >= width of value 2019-01-10 21:37:32 +08:00
drivers coresight: Use event attributes for sink selection 2019-02-06 10:00:39 -03:00
firmware kbuild: change filechk to surround the given command with { } 2019-01-06 09:46:51 +09:00
fs for-5.0-rc4-tag 2019-02-03 08:48:33 -08:00
include coresight: perf: Add "sinks" group to PMU directory 2019-02-06 10:00:39 -03:00
init psi: clarify the Kconfig text for the default-disable option 2019-02-01 15:46:24 -08:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel perf/aux: Make perf_event accessible to setup_aux() 2019-02-06 10:00:39 -03:00
lib lib/test_kmod.c: potential double free in error handling 2019-02-01 15:46:23 -08:00
mm mm: migrate: don't rely on __PageMovable() of newpage after unlocking it 2019-02-01 15:46:24 -08:00
net net: set default network namespace in init_dummy_netdev() 2019-01-29 11:29:55 -08:00
samples samples/bpf: workaround clang asm goto compilation errors 2019-01-15 20:57:30 +01:00
scripts Bug fixes for gcc-plugins 2019-01-21 13:07:03 +13:00
security apparmor: Fix aa_label_build() error handling for failed merges 2019-02-01 08:01:39 -08:00
sound sound fixes for 5.0-rc5 2019-01-31 10:00:00 -08:00
tools perf beauty waitid options: Fix up prefix showing logic 2019-02-14 13:31:12 -03:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt KVM: validate userspace input in kvm_clear_dirty_log_protect() 2019-01-11 18:38:07 +01:00
.clang-format clang-format: Update .clang-format with the latest for_each macro list 2019-01-19 19:26:06 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap A few early MIPS fixes for 4.21: 2019-01-05 12:48:25 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Add CREDITS entry for Shaohua Li 2019-01-04 14:27:09 -07:00
Kbuild kbuild: use assignment instead of define ... endef for filechk_* rules 2019-01-06 10:22:35 +09:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-03 09:08:12 -08:00
Makefile Linux 5.0-rc5 2019-02-03 13:48:04 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.