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Arnaldo Carvalho de Melo a7672d1df5 perf evlist: Change the COMM when preparing the workload
It was reported that --exclude-perf wasn't working, as tracepoints were
appearing in 'perf script' output as having the 'perf' COMM, that is
just the window in evlist__prepare_workload() after the fork() and
before the execvp() call for workloads specified in the command line.

Example:

  # perf record -e kmem:kmalloc --filter 'bytes_alloc<650 && bytes_alloc>620' --exclude-perf -e kmem:kfree --exclude-perf -aR sleep 30

Then:

  # perf script
          perf 15905 [009] 1498.356094: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
          perf 15905 [009] 1498.356116: kmem:kfree: call_site=free_bprm+0x8f ptr=(nil)
          perf 15905 [009] 1498.356116: kmem:kfree: call_site=do_execveat_common+0x19d ptr=0xffff9cf750421c00
          perf 15905 [009] 1498.356138: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
          perf 15905 [009] 1498.356148: kmem:kfree: call_site=free_bprm+0x8f ptr=(nil)
          perf 15905 [009] 1498.356148: kmem:kfree: call_site=do_execveat_common+0x19d ptr=0xffff9cf750421c00
          perf 15905 [009] 1498.356168: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
          perf 15905 [009] 1498.356176: kmem:kfree: call_site=free_bprm+0x8f ptr=(nil)
  <SNIP>
          perf 15905 [009] 1498.356348: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
          perf 15905 [014] 1498.356386: kmem:kfree: call_site=security_compute_sid.part.0+0x3b2 ptr=(nil)
          perf 15905 [014] 1498.356423: kmem:kfree: call_site=load_elf_binary+0x207 ptr=0xffff9cf5b2a34220
          perf 15905 [014] 1498.356694: kmem:kfree: call_site=__free_slab+0xb5 ptr=0xffff9cf6d0b3b000
         sleep 15905 [014] 1498.356739: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)

Use prctl() to show that that is just the preparation of the workload:

  # perf script
     perf-exec 19036 [009] 2199.357582: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
     perf-exec 19036 [009] 2199.357604: kmem:kfree: call_site=free_bprm+0x8f ptr=(nil)
     perf-exec 19036 [009] 2199.357604: kmem:kfree: call_site=do_execveat_common+0x19d ptr=0xffff9cf786459800
     perf-exec 19036 [009] 2199.357630: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
  <SNIP>
     perf-exec 19036 [000] 2199.358277: kmem:kfree: call_site=__free_slab+0xb5 ptr=0xffff9cf786fb9c00
     perf-exec 19036 [000] 2199.358278: kmem:kfree: call_site=__free_slab+0xb5 ptr=0xffff9cf786458200
     perf-exec 19036 [000] 2199.358279: kmem:kfree: call_site=__free_slab+0xb5 ptr=0xffff9cf786458600
         sleep 19036 [000] 2199.358316: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
         sleep 19036 [000] 2199.358323: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=(nil)
         sleep 19036 [000] 2199.358330: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=0xffff9cf58be2d000
         sleep 19036 [000] 2199.358337: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=0xffff9cf58be2d000
         sleep 19036 [000] 2199.358339: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=0xffff9cf58be2d000
         sleep 19036 [000] 2199.358341: kmem:kfree: call_site=perf_event_mmap+0x279 ptr=0xffff9cf58be2d000

Reporter: zhanweiw <wingfancy@hotmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212213
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-03-15 10:13:22 -03:00
Documentation block-5.12-2021-03-05 2021-03-05 12:59:37 -08:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
arch Merge branch 'parisc-5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2021-03-07 13:28:31 -08:00
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certs certs: Replace K{U,G}IDT_INIT() with GLOBAL_ROOT_{U,G}ID 2021-01-21 16:16:10 +00:00
crypto Keyrings miscellany 2021-02-23 16:09:23 -08:00
drivers powerpc fixes for 5.12 #2 2021-03-07 13:24:44 -08:00
fs pstore fixes for v5.12-rc2 2021-03-05 17:21:25 -08:00
include block-5.12-2021-03-05 2021-03-05 12:59:37 -08:00
init kbuild: fix UNUSED_KSYMS_WHITELIST for Clang LTO 2021-02-28 15:19:21 +09:00
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lib Merge branch 'kmap-conversion-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux 2021-03-01 11:24:18 -08:00
mm swap: fix swapfile read/write offset 2021-03-02 17:25:46 -07:00
net io_uring-worker.v3-2021-02-25 2021-02-27 08:29:02 -08:00
samples treewide: Miguel has moved 2021-02-26 09:41:03 -08:00
scripts gcc-plugins fixes for v5.12-rc2 2021-03-05 17:23:03 -08:00
security Keyrings miscellany 2021-02-23 16:09:23 -08:00
sound ALSA: hda/realtek: Apply dual codec quirks for MSI Godlike X570 board 2021-03-03 15:25:03 +01:00
tools perf evlist: Change the COMM when preparing the workload 2021-03-15 10:13:22 -03:00
usr Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
virt KVM: x86/mmu: Consider the hva in mmu_notifier retry 2021-02-22 13:16:53 -05:00
.clang-format cxl for 5.12 2021-02-24 09:38:36 -08:00
.cocciconfig
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Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
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MAINTAINERS RISC-V Patches for the 5.12 Merge Window 2021-02-26 10:28:35 -08:00
Makefile Linux 5.12-rc2 2021-03-05 17:33:41 -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.