Linux kernel source tree
 
 
 
 
 
 
Go to file
Namhyung Kim c776df09f4 perf stat: Fix handling of --for-each-cgroup with --bpf-counters to match non BPF mode
[ Upstream commit 54b353a20c ]

The --for-each-cgroup can have the same cgroup multiple times, but this
confuses BPF counters (since they have the same cgroup id), making only
the last cgroup events to be counted.

Let's check the cgroup name before adding a new entry to the cgroups
list.

Before:

  $ sudo ./perf stat -a --bpf-counters --for-each-cgroup /,/ sleep 1

   Performance counter stats for 'system wide':

       <not counted> msec cpu-clock                        /
       <not counted>      context-switches                 /
       <not counted>      cpu-migrations                   /
       <not counted>      page-faults                      /
       <not counted>      cycles                           /
       <not counted>      instructions                     /
       <not counted>      branches                         /
       <not counted>      branch-misses                    /
            8,016.04 msec cpu-clock                        /                #    7.998 CPUs utilized
               6,152      context-switches                 /                #  767.461 /sec
                 250      cpu-migrations                   /                #   31.187 /sec
                 442      page-faults                      /                #   55.139 /sec
         613,111,487      cycles                           /                #    0.076 GHz
         280,599,604      instructions                     /                #    0.46  insn per cycle
          57,692,724      branches                         /                #    7.197 M/sec
           3,385,168      branch-misses                    /                #    5.87% of all branches

         1.002220125 seconds time elapsed

After it becomes similar to the non-BPF mode:

  $ sudo ./perf stat -a --bpf-counters --for-each-cgroup /,/  sleep 1

   Performance counter stats for 'system wide':

            8,013.38 msec cpu-clock                        /                #    7.998 CPUs utilized
               6,859      context-switches                 /                #  855.944 /sec
                 334      cpu-migrations                   /                #   41.680 /sec
                 345      page-faults                      /                #   43.053 /sec
         782,326,119      cycles                           /                #    0.098 GHz
         471,645,724      instructions                     /                #    0.60  insn per cycle
          94,963,430      branches                         /                #   11.851 M/sec
           3,685,511      branch-misses                    /                #    3.88% of all branches

         1.001864539 seconds time elapsed

Committer notes:

As a reminder, to test with BPF counters one has to use BUILD_BPF_SKEL=1
in the make command line and have clang/llvm installed when building
perf, otherwise the --bpf-counters option will not be available:

  # perf stat -a --bpf-counters --for-each-cgroup /,/ sleep 1
  Error: unknown option `bpf-counters'

   Usage: perf stat [<options>] [<command>]

      -a, --all-cpus        system-wide collection from all CPUs
  <SNIP>
  #

Fixes: bb1c15b60b ("perf stat: Support regex pattern in --for-each-cgroup")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: bpf@vger.kernel.org
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/r/20230104064402.1551516-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-12 12:02:31 +01:00
Documentation ext4: journal_path mount options should follow links 2023-01-07 11:11:59 +01:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
arch ARM: renumber bits related to _TIF_WORK_MASK 2023-01-12 12:01:55 +01:00
block block: mq-deadline: Do not break sequential write streams to zoned HDDs 2023-01-07 11:11:51 +01:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto crypto: tcrypt - Fix multibuffer skcipher speed test mem leak 2022-12-31 13:32:34 +01:00
drivers usb: rndis_host: Secure rndis_query check against int overflow 2023-01-12 12:02:29 +01:00
fs fs/ntfs3: don't hold ni_lock when calling truncate_setsize() 2023-01-12 12:02:28 +01:00
include netfilter: ipset: Rework long task execution when adding/deleting entries 2023-01-12 12:02:26 +01:00
init init/Kconfig: fix CC_HAS_ASM_GOTO_TIED_OUTPUT test with dash 2022-11-22 22:42:38 +09:00
io_uring io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups 2023-01-04 11:28:48 +01:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel bpf: Always use maximal size for copy_array() 2023-01-12 12:02:15 +01:00
lib test_kprobes: Fix implicit declaration error of test_kprobes 2023-01-07 11:11:55 +01:00
mm hugetlb: really allocate vma lock for all sharable vmas 2023-01-07 11:11:55 +01:00
net netfilter: ipset: Rework long task execution when adding/deleting entries 2023-01-12 12:02:26 +01:00
rust Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
samples samples: vfio-mdev: Fix missing pci_disable_device() in mdpy_fb_probe() 2022-12-31 13:32:42 +01:00
scripts - Handle different output of readelf on different distros running 2022-11-27 12:08:17 -08:00
security device_cgroup: Roll back to original exceptions after copy failure 2023-01-07 11:11:56 +01:00
sound ASoC: jz4740-i2s: Handle independent FIFO flush bits 2023-01-07 11:11:51 +01:00
tools perf stat: Fix handling of --for-each-cgroup with --bpf-counters to match non BPF mode 2023-01-12 12:02:31 +01:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt Merge branch 'kvm-dwmw2-fixes' into HEAD 2022-11-23 18:59:45 -05:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add `.rustfmt.toml` 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
Makefile Linux 6.1.4 2023-01-07 11:12:04 +01:00
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.