Messages in this thread | | | Date | Tue, 6 Dec 2016 12:23:30 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH V2 04/13] perf/core: output multiplexing overhead |
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On Fri, Dec 02, 2016 at 04:19:12PM -0500, kan.liang@intel.com wrote: > From: Kan Liang <kan.liang@intel.com> > > Multiplexing overhead is one of the key overhead when the number of > events is more than available counters. > > The multiplexing overhead PERF_CORE_MUX_OVERHEAD is a common overhead > type. >
> diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h > index fe7b1fb..355086f 100644 > --- a/include/uapi/linux/perf_event.h > +++ b/include/uapi/linux/perf_event.h > @@ -999,6 +999,7 @@ struct perf_branch_entry { > */ > enum perf_record_overhead_type { > PERF_CORE_OVERHEAD = 0, > + PERF_CORE_MUX_OVERHEAD = 0,
'0' already had a name ?!
> > PERF_PMU_OVERHEAD = 20, > PERF_PMU_SAMPLE_OVERHEAD = 20,
Same here I suppose, why are there two with the same name?
> diff --git a/kernel/events/core.c b/kernel/events/core.c > index 306bc92..025a19d 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -1830,6 +1830,9 @@ event_sched_out(struct perf_event *event, > if (event->attr.exclusive || !cpuctx->active_oncpu) > cpuctx->exclusive = 0; > > + if (log_overhead && cpuctx->mux_overhead.nr) > + perf_log_overhead(event, PERF_CORE_MUX_OVERHEAD, &cpuctx->mux_overhead); > +
This isn't mentioned in the Changelog. Why is it here?
> perf_pmu_enable(event->pmu); > } >
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