linux-toradex.git/tools/perf/util/pmu.y, branch v6.15

perf pmu: Add YYDEBUG

2023-09-12T20:47:00+00:00

YYDEBUG enables line numbers and other error helpers in the generated
pmu-bison.c. Conditionally enabled only for debug builds.

Signed-off-by: Ian Rogers 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Gaosheng Cui 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Peter Zijlstra 
Cc: Rob Herring 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230911170559.4037734-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Make the loading of formats lazy

2023-08-24T13:38:04+00:00

The sysfs format files are loaded eagerly in a PMU. Add a flag so that
we create the format but only load the contents when necessary.

Reduce the size of the value in struct perf_pmu_format and avoid holes
so there is no additional space requirement.

For "perf stat -e cycles true" this reduces the number of openat calls
from 648 to 573 (about 12%). The benchmark pmu scan speed is improved
by roughly 5%.

Before:

  $ perf bench internals pmu-scan
  Computing performance of sysfs PMU event scan for 100 times
    Average core PMU scanning took: 1061.100 usec (+- 9.965 usec)
    Average PMU scanning took: 4725.300 usec (+- 260.599 usec)

After:

  $ perf bench internals pmu-scan
  Computing performance of sysfs PMU event scan for 100 times
    Average core PMU scanning took: 989.170 usec (+- 6.873 usec)
    Average PMU scanning took: 4520.960 usec (+- 251.272 usec)

Committer testing:

On a AMD Ryzen 5950x:

Before:

  $ perf bench internals pmu-scan -i1000
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 563.466 usec (+- 1.008 usec)
    Average PMU scanning took: 1619.174 usec (+- 23.627 usec)
  $ perf stat -r5 perf bench internals pmu-scan -i1000
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 583.401 usec (+- 2.098 usec)
    Average PMU scanning took: 1677.352 usec (+- 24.636 usec)
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 553.254 usec (+- 0.825 usec)
    Average PMU scanning took: 1635.655 usec (+- 24.312 usec)
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 557.733 usec (+- 0.980 usec)
    Average PMU scanning took: 1600.659 usec (+- 23.344 usec)
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 554.906 usec (+- 0.774 usec)
    Average PMU scanning took: 1595.338 usec (+- 23.288 usec)
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 551.798 usec (+- 0.967 usec)
    Average PMU scanning took: 1623.213 usec (+- 23.998 usec)

   Performance counter stats for 'perf bench internals pmu-scan -i1000' (5 runs):

             3276.82 msec task-clock:u                     #    0.990 CPUs utilized               ( +-  0.82% )
                   0      context-switches:u               #    0.000 /sec
                   0      cpu-migrations:u                 #    0.000 /sec
                1008      page-faults:u                    #  307.615 /sec                        ( +-  0.04% )
         12049614778      cycles:u                         #    3.677 GHz                         ( +-  0.07% )  (83.34%)
           117507478      stalled-cycles-frontend:u        #    0.98% frontend cycles idle        ( +-  0.33% )  (83.32%)
            27106761      stalled-cycles-backend:u         #    0.22% backend cycles idle         ( +-  9.55% )  (83.36%)
         33294953848      instructions:u                   #    2.76  insn per cycle
                                                           #    0.00  stalled cycles per insn     ( +-  0.03% )  (83.31%)
          6849825049      branches:u                       #    2.090 G/sec                       ( +-  0.03% )  (83.37%)
            71533903      branch-misses:u                  #    1.04% of all branches             ( +-  0.20% )  (83.30%)

              3.3088 +- 0.0302 seconds time elapsed  ( +-  0.91% )

  $

After:

  $ perf stat -r5 perf bench internals pmu-scan -i1000
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 550.702 usec (+- 0.958 usec)
    Average PMU scanning took: 1566.577 usec (+- 22.747 usec)
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 548.315 usec (+- 0.555 usec)
    Average PMU scanning took: 1565.499 usec (+- 22.760 usec)
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 548.073 usec (+- 0.555 usec)
    Average PMU scanning took: 1586.097 usec (+- 23.299 usec)
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 561.184 usec (+- 2.709 usec)
    Average PMU scanning took: 1567.153 usec (+- 22.548 usec)
  # Running 'internals/pmu-scan' benchmark:
  Computing performance of sysfs PMU event scan for 1000 times
    Average core PMU scanning took: 546.987 usec (+- 0.553 usec)
    Average PMU scanning took: 1562.814 usec (+- 22.729 usec)

   Performance counter stats for 'perf bench internals pmu-scan -i1000' (5 runs):

             3170.86 msec task-clock:u                     #    0.992 CPUs utilized               ( +-  0.22% )
                   0      context-switches:u               #    0.000 /sec
                   0      cpu-migrations:u                 #    0.000 /sec
                1010      page-faults:u                    #  318.526 /sec                        ( +-  0.04% )
         11890047674      cycles:u                         #    3.750 GHz                         ( +-  0.14% )  (83.27%)
           119090499      stalled-cycles-frontend:u        #    1.00% frontend cycles idle        ( +-  0.46% )  (83.40%)
            32502449      stalled-cycles-backend:u         #    0.27% backend cycles idle         ( +-  8.32% )  (83.30%)
         33119141261      instructions:u                   #    2.79  insn per cycle
                                                    #    0.00  stalled cycles per insn     ( +-  0.01% )  (83.37%)
          6812816561      branches:u                       #    2.149 G/sec                       ( +-  0.01% )  (83.29%)
            70157855      branch-misses:u                  #    1.03% of all branches             ( +-  0.28% )  (83.38%)

             3.19710 +- 0.00826 seconds time elapsed  ( +-  0.26% )

  $

Signed-off-by: Ian Rogers 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Gaosheng Cui 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jing Zhang 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Rob Herring 
Link: https://lore.kernel.org/r/20230824041330.266337-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Reduce scope of perf_pmu_error()

2023-08-23T11:49:13+00:00

Move declaration from header file to pmu.y and make static.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Gaosheng Cui 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jing Zhang 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Rob Herring 
Link: https://lore.kernel.org/r/20230823080828.1460376-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Move perf_pmu__set_format to pmu.y

2023-08-23T11:48:49+00:00

Avoid having the function in the C and header file, as it is only used
locally by pmu.y.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Gaosheng Cui 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jing Zhang 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Rob Herring 
Link: https://lore.kernel.org/r/20230823080828.1460376-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf build: Disable fewer bison warnings

2023-08-03T20:01:24+00:00

If bison is version 3.8.2, reduce the number of bison C warnings
disabled. Earlier bison versions have all C warnings disabled. Avoid
implicit declarations of yylex by adding the declaration in the C
file. A header can't be included as a circular dependency would occur
due to the lexer using the bison defined tokens.

Committer notes:

Some recent versions of gcc and clang (noticed on Alpine Linux 3.17,
edge, clearlinux, fedora 37, etc.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andrii Nakryiko 
Cc: Eduard Zingerman 
Cc: Gaosheng Cui 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Rob Herring 
Cc: Tom Rix 
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230728064917.767761-6-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Make parser reentrant

2023-04-07T00:40:28+00:00

By default bison uses global state for compatibility with yacc. Make
the parser reentrant so that it may be used in asynchronous and
multithreaded situations.

Signed-off-by: Ian Rogers 
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Gaosheng Cui 
Cc: German Gomez 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jing Zhang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Rob Herring 
Cc: Sean Christopherson 
Cc: Suzuki Poulouse 
Link: https://lore.kernel.org/r/20230406065224.2553640-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf: Skip and warn on unknown format 'configN' attrs

2022-10-14T15:23:09+00:00

If the kernel exposes a new perf_event_attr field in a format attr, perf
will return an error stating the specified PMU can't be found. For
example, a format attr with 'config3:0-63' causes an error as config3 is
unknown to perf. This causes a compatibility issue between a newer
kernel with older perf tool.

Before this change with a kernel adding 'config3' I get:

  $ perf record -e arm_spe// -- true
  event syntax error: 'arm_spe//'
                       \___ Cannot find PMU `arm_spe'. Missing kernel support?
  Run 'perf list' for a list of valid events

   Usage: perf record [] []
      or: perf record [] --  []

      -e, --event    event selector. use 'perf list' to list
  available events

After this change, I get:

  $ perf record -e arm_spe// -- true
  WARNING: 'arm_spe_0' format 'inv_event_filter' requires 'perf_event_attr::config3' which is not supported by this version of perf!
  [ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 0.091 MB perf.data ]

To support unknown configN formats, rework the YACC implementation to
pass any config[0-9]+ format to perf_pmu__new_format() to handle with a
warning.

Reviewed-by: Namhyung Kim 
Signed-off-by: Rob Herring 
Tested-by: Leo Yan 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Peter Zijlstra 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220914-arm-perf-tool-spe1-2-v2-v4-1-83c098e6212e@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Remove perf_pmu_lex() needless declaration

2022-10-04T11:55:22+00:00

It builds without it, perhaps with some older combination of flex/bison
we needed this, clean it up a bit removing this.

Signed-off-by: Gaosheng Cui 
Cc: Alexander Shishkin 
Cc: Athira Jajeev 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: https://lore.kernel.org/r/20220909044542.1087870-3-cuigaosheng1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix build with bison 2.3 and older.

2013-02-14T19:12:34+00:00

The %name-prefix "prefix" syntax is not available on bison 2.3 and
older. Substitute with the -p "prefix" command-line option for
compatibility with older versions of bison.

This patch fixes this build error with older versions of bison.

    CC util/sysfs.o
    BISON util/pmu-bison.c
util/pmu.y:2.14-24: syntax error, unexpected string, expecting =
make: *** [util/pmu-bison.c] Error 1

Signed-off-by: Vinson Lee 
Tested-by: Li Zefan 
Cc: stable@vger.kernel.org # 3.4+
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Li Zefan 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Pekka Enberg 
Link: http://lkml.kernel.org/r/1360792138-29186-1-git-send-email-vlee@twitter.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use __maybe_used for unused variables

2012-09-11T15:19:15+00:00

perf defines both __used and __unused variables to use for marking
unused variables. The variable __used is defined to
__attribute__((__unused__)), which contradicts the kernel definition to
__attribute__((__used__)) for new gcc versions. On Android, __used is
also defined in system headers and this leads to warnings like: warning:
'__used__' attribute ignored

__unused is not defined in the kernel and is not a standard definition.
If __unused is included everywhere instead of __used, this leads to
conflicts with glibc headers, since glibc has a variables with this name
in its headers.

The best approach is to use __maybe_unused, the definition used in the
kernel for __attribute__((unused)). In this way there is only one
definition in perf sources (instead of 2 definitions that point to the
same thing: __used and __unused) and it works on both Linux and Android.
This patch simply replaces all instances of __used and __unused with
__maybe_unused.

Signed-off-by: Irina Tirdea 
Acked-by: Pekka Enberg 
Cc: David Ahern 
Cc: Ingo Molnar 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/1347315303-29906-7-git-send-email-irina.tirdea@intel.com
[ committer note: fixed up conflict with a116e05 in builtin-sched.c ]
Signed-off-by: Arnaldo Carvalho de Melo