Re: [PATCH v8 0/7] Event parsing fixes

[Namhyung Kim <namhyung@kernel.org>]

On Wed, Sep 25, 2024 at 03:13:38PM +0100, James Clark wrote:
> I rebased this one and made some other fixes so that I could test it,
> so I thought I'd repost it here in case it's helpful. I also added a
> new test.
> 
> But for the testing it all looks ok.
> 
> There is one small difference where it now hides _all_ default
> <not supported> events, when previously it would only hide some
> selected subset of events like "stalled-cycles-frontend". I think
> this is now more consistent across platforms because, for example,
> Apple M only has cycles and instructions, and the rest of the
> default events would always show as <not supported> there.
> 
> Tested on Raptor Lake, Kaby Lake, Juno, N1, Ampere (with the DSU
> cycles PMU) and I also faked an Apple M on Juno. 

Hmm.. I got a segfault with 'perf stat true' on my Zen2 box.

  $ gdb -q -args ./perf stat true
  Reading symbols from ./perf...
  (gdb) r
  Starting program: /home/namhyung/tmp/perf stat true
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
  
  Program received signal SIGSEGV, Segmentation fault.
  0x00005555557e04b5 in perf_pmu__is_fake (pmu=0x0) at util/pmu.c:1173
  1173		return pmu->type == PERF_PMU_TYPE_FAKE;
  (gdb) bt
  #0  0x00005555557e04b5 in perf_pmu__is_fake (pmu=0x0) at util/pmu.c:1173
  #1  0x00005555558c1b8b in evsel__sys_has_perf_metrics (evsel=0x5555560cc4b0) at arch/x86/util/evsel.c:50
  #2  0x00005555558c1c33 in arch_evsel__must_be_in_group (evsel=0x5555560cc4b0) at arch/x86/util/evsel.c:64
  #3  0x00005555557773a4 in parse_events__sort_events_and_fix_groups (list=0x7fffffff9ad0) at util/parse-events.c:2098
  #4  0x0000555555777793 in __parse_events (evlist=0x5555560aa880, 
      str=0x5555558d6498 "context-switches,cpu-migrations,page-faults,instructions,cycles,stalled-cycles-frontend,stalled-cycles-backend,branches,branch-misses", pmu_filter=0x0, err=0x7fffffff9bd0, fake_pmu=false, warn_if_reordered=true, fake_tp=false) at util/parse-events.c:2186
  #5  0x00005555555c787f in parse_events (evlist=0x5555560aa880, 
      str=0x5555558d6498 "context-switches,cpu-migrations,page-faults,instructions,cycles,stalled-cycles-frontend,stalled-cycles-backend,branches,branch-misses", err=0x7fffffff9bd0) at util/parse-events.h:41
  #6  0x00005555555cce39 in add_default_events () at builtin-stat.c:1977
  #7  0x00005555555cf928 in cmd_stat (argc=1, argv=0x7fffffffd840) at builtin-stat.c:2724
  #8  0x000055555564cb81 in run_builtin (p=0x555556024548 <commands+360>, argc=2, argv=0x7fffffffd840) at perf.c:351
  #9  0x000055555564ce28 in handle_internal_command (argc=2, argv=0x7fffffffd840) at perf.c:404
  #10 0x000055555564cf81 in run_argv (argcp=0x7fffffffd63c, argv=0x7fffffffd630) at perf.c:448
  #11 0x000055555564d2cf in main (argc=2, argv=0x7fffffffd840) at perf.c:562

Thanks,
Namhyung

> 
> Changes since v7:
>   * Resolve conflicts and rebase onto perf-tools-next 1de5b5dcb835
>   * Fix build error by using the new perf_pmu__is_fake()
> 
> Changes since v6:
>   * Fix empty PMU name in perf report
>   * Rebase onto perf-tools-next 003265bb6f02
> 
> Changes since v5:
>   * Test on x86 non hybrid
>   * Assume 1 PMU in the test when no PMUs expose /cpus file
> 
> Changes since v4:
> 
>   * Hide all <not supported> default events when not verbose
>   * Remove previous note about <not supported> behavior from the cover
>     letter and replace it with a new note about the new behavior
>  
> Changes since v3:
> 
>   * Rebase onto perf-tools-next 6236ebe07
>   * Fix Intel TPEBS counting mode test
>   * Fix arm-spe build
>   * Add support for DT devices in stat test
>   * Add a new test for hybrid perf stat default arguments
> 
> Ian Rogers (5):
>   perf evsel: Add alternate_hw_config and use in evsel__match
>   perf stat: Uniquify event name improvements
>   perf stat: Remove evlist__add_default_attrs use strings
>   perf evsel x86: Make evsel__has_perf_metrics work for legacy events
>   perf evsel: Remove pmu_name
> 
> James Clark (2):
>   perf test: Make stat test work on DT devices
>   perf test: Add a test for default perf stat command
> 
>  tools/perf/arch/arm64/util/arm-spe.c          |   4 +-
>  tools/perf/arch/x86/util/evlist.c             |  74 +----
>  tools/perf/arch/x86/util/evsel.c              |  35 ++-
>  tools/perf/builtin-diff.c                     |   6 +-
>  tools/perf/builtin-stat.c                     | 291 +++++++-----------
>  tools/perf/tests/parse-events.c               |   2 +-
>  tools/perf/tests/shell/stat.sh                |  37 ++-
>  .../perf/tests/shell/test_stat_intel_tpebs.sh |  11 +-
>  tools/perf/util/evlist.c                      |  46 +--
>  tools/perf/util/evlist.h                      |  12 -
>  tools/perf/util/evsel.c                       |  28 +-
>  tools/perf/util/evsel.h                       |  22 +-
>  tools/perf/util/metricgroup.c                 |   4 +-
>  tools/perf/util/parse-events.c                |  60 ++--
>  tools/perf/util/parse-events.h                |   8 +-
>  tools/perf/util/parse-events.y                |   2 +-
>  tools/perf/util/pmu.c                         |   8 +-
>  tools/perf/util/pmu.h                         |   3 +-
>  tools/perf/util/stat-display.c                | 109 +++++--
>  tools/perf/util/stat-shadow.c                 |  14 +-
>  tools/perf/util/stat.c                        |   2 +-
>  21 files changed, 363 insertions(+), 415 deletions(-)
> 
> -- 
> 2.34.1
>