[PATCH v4 0/7] Event parsing fixes
Liang, Kan
kan.liang at linux.intel.com
Thu Aug 22 07:32:16 PDT 2024
On 2024-08-22 9:24 a.m., 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 shows "stalled-cycles-..."
> as <not supported> events, when before it just didn't show them at all when
> they weren't supported:
>
> $ perf stat -- true
>
> Performance counter stats for 'true':
>
> 0.66 msec task-clock # 0.384 CPUs utilized
> 0 context-switches # 0.000 /sec
> 0 cpu-migrations # 0.000 /sec
> 52 page-faults # 78.999 K/sec
> <not counted> cpu_atom/instructions/ (0.00%)
> 978,399 cpu_core/instructions/ # 1.02 insn per cycle
> <not counted> cpu_atom/cycles/ (0.00%)
> 959,722 cpu_core/cycles/ # 1.458 GHz
> <not supported> cpu_atom/stalled-cycles-frontend/
> <not supported> cpu_core/stalled-cycles-frontend/
>
Intel didn't support the events for a very long time. It would impact
many existing generations and all future generations.
The current method is to hide the non-exist events. The TopdownL1 is an
example. If it doesn't exist in the json file, perf stat will not
display it.
I don't think it's a good idea to disclose non-exist events in the perf
stat default.
The <not supported> doesn't help here, since there could be many reasons
that the perf tool fails to open a counter. It just provides a
misleading message for an event that never existed.
Thanks,
Kan
> I don't think that's a big deal though and could probably be fixed up
> later if we really want to.
>
> Tested on Raptor Lake, Juno, N1, Ampere (with the DSU cycles PMU) and
> I also faked an Apple M on Juno.
>
> 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 | 33 +-
> .../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 | 58 ++--
> tools/perf/util/parse-events.h | 8 +-
> tools/perf/util/parse-events.y | 2 +-
> tools/perf/util/pmu.c | 6 +-
> tools/perf/util/pmu.h | 2 +-
> tools/perf/util/stat-display.c | 101 ++++--
> tools/perf/util/stat-shadow.c | 14 +-
> tools/perf/util/stat.c | 2 +-
> 21 files changed, 348 insertions(+), 413 deletions(-)
>
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