From: Kan Liang <[email protected]> There is no way to get exact auto-reload times and value which needed for event update unless flush the PEBS buffer.
Introduce intel_pmu_auto_reload_read() to drain the PEBS buffer for auto reload event. To prevent the race, the drain_pebs() only be called when the PMU is disabled. Signed-off-by: Kan Liang <[email protected]> --- arch/x86/events/intel/ds.c | 9 +++++++++ arch/x86/events/perf_event.h | 2 ++ 2 files changed, 11 insertions(+) diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index f519ebc..406f3ba 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -1303,6 +1303,15 @@ get_next_pebs_record_by_bit(void *base, void *top, int bit) return NULL; } +void intel_pmu_auto_reload_read(struct perf_event *event) +{ + WARN_ON(!(event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD)); + + perf_pmu_disable(event->pmu); + intel_pmu_drain_pebs_buffer(); + perf_pmu_enable(event->pmu); +} + /* * Special variant of intel_pmu_save_and_restart() for auto-reload. */ diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h index 805400b..f4720a9 100644 --- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -923,6 +923,8 @@ void intel_pmu_pebs_disable_all(void); void intel_pmu_pebs_sched_task(struct perf_event_context *ctx, bool sched_in); +void intel_pmu_auto_reload_read(struct perf_event *event); + void intel_ds_init(void); void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in); -- 2.7.4
