Messages in this thread | | | Subject | Re: [PATCH 4/4] perf/x86/intel: drain PEBS buffer in event read | From | "Liang, Kan" <> | Date | Tue, 19 Dec 2017 15:10:04 -0500 |
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On 12/19/2017 2:02 PM, Peter Zijlstra wrote: > On Mon, Dec 18, 2017 at 03:34:51AM -0800, kan.liang@linux.intel.com wrote: >> --- a/arch/x86/events/intel/ds.c >> +++ b/arch/x86/events/intel/ds.c >> @@ -926,6 +926,16 @@ void intel_pmu_pebs_del(struct perf_event *event) >> pebs_update_state(needed_cb, cpuc, event->ctx->pmu); >> } >> >> +void intel_pmu_pebs_read(struct perf_event *event) >> +{ >> + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); >> + >> + if (pebs_needs_sched_cb(cpuc)) >> + return intel_pmu_drain_pebs_buffer(); >> + >> + x86_perf_event_update(event, 0, 0); >> +} > > This is completely broken.. what if @event isn't a pebs event, but we > do have an auto-reloading pebs event configured? >
precise_ip will be checked before intel_pmu_pebs_read is called. So @event must be a pebs event.
@@ -2060,6 +2060,14 @@ static void intel_pmu_del_event(struct perf_event *event) intel_pmu_pebs_del(event); }
+static void intel_pmu_read_event(struct perf_event *event) +{ + if (event->attr.precise_ip) + return intel_pmu_pebs_read(event); + + x86_perf_event_update(event, 0, 0); +}
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