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| author |   Kan Liang <kan.liang@linux.intel.com> | 2022-09-01 06:09:55 -0700 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2022-09-06 11:33:01 +0200 |
| commit | 47a3aeb39e8dc099ae431cd8b46bdf218f5511b2 (patch) | |
| tree | 4ee142656104b870e7537c4d354d87f852952a38 /arch/x86/events | |
| parent | perf: Add sample_flags to indicate the PMU-filled sample data (diff) | |
| download | linux-dev-47a3aeb39e8dc099ae431cd8b46bdf218f5511b2.tar.xz linux-dev-47a3aeb39e8dc099ae431cd8b46bdf218f5511b2.zip | |
perf/x86/intel/pebs: Fix PEBS timestamps overwritten
The PEBS TSC-based timestamps do not appear correctly in the final
perf.data output file from perf record.
The data->time field setup by PEBS in the setup_pebs_fixed_sample_data()
is later overwritten by perf_events generic code in
perf_prepare_sample(). There is an ordering problem.
Set the sample flags when the data->time is updated by PEBS.
The data->time field will not be overwritten anymore.
Reported-by: Andreas Kogler <andreas.kogler.0x@gmail.com>
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220901130959.1285717-3-kan.liang@linux.intel.com
Diffstat (limited to 'arch/x86/events')
| -rw-r--r-- | arch/x86/events/intel/ds.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index ba60427caa6d..cdd857bd2dd6 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -1635,8 +1635,10 @@ static void setup_pebs_fixed_sample_data(struct perf_event *event, * We can only do this for the default trace clock. */ if (x86_pmu.intel_cap.pebs_format >= 3 && - event->attr.use_clockid == 0) + event->attr.use_clockid == 0) { data->time = native_sched_clock_from_tsc(pebs->tsc); + data->sample_flags |= PERF_SAMPLE_TIME; + } if (has_branch_stack(event)) data->br_stack = &cpuc->lbr_stack; @@ -1697,8 +1699,10 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event, perf_sample_data_init(data, 0, event->hw.last_period); data->period = event->hw.last_period; - if (event->attr.use_clockid == 0) + if (event->attr.use_clockid == 0) { data->time = native_sched_clock_from_tsc(basic->tsc); + data->sample_flags |= PERF_SAMPLE_TIME; + } /* * We must however always use iregs for the unwinder to stay sane; the |