The following commit has been merged into the perf/core branch of tip: Commit-ID: 47a3aeb39e8dc099ae431cd8b46bdf218f5511b2 Gitweb: https://git.kernel.org/tip/47a3aeb39e8dc099ae431cd8b46bdf218f5511b2 Author: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> AuthorDate: Thu, 01 Sep 2022 06:09:55 -07:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Tue, 06 Sep 2022 11:33:01 +02:00 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@xxxxxxxxx> Reported-by: Stephane Eranian <eranian@xxxxxxxxxx> Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220901130959.1285717-3-kan.liang@xxxxxxxxxxxxxxx --- arch/x86/events/intel/ds.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index ba60427..cdd857b 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
![]() |