Messages in this thread |  | | Subject | Re: [PATCH v6 1/3] perf/core: use rb trees for pinned/flexible groups | From | Alexey Budankov <> | Date | Mon, 7 Aug 2017 18:22:59 +0300 |
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On 04.08.2017 17:53, Peter Zijlstra wrote: > On Thu, Aug 03, 2017 at 11:30:09PM +0300, Alexey Budankov wrote: >> On 03.08.2017 16:00, Peter Zijlstra wrote: >>> On Wed, Aug 02, 2017 at 11:13:54AM +0300, Alexey Budankov wrote: > >>>> @@ -2759,13 +2932,13 @@ static void ctx_sched_out(struct perf_event_context *ctx, >>>> >>>> perf_pmu_disable(ctx->pmu); >>>> if (is_active & EVENT_PINNED) { >>>> - list_for_each_entry(event, &ctx->pinned_groups, group_entry) >>>> - group_sched_out(event, cpuctx, ctx); >>>> + perf_event_groups_iterate(&ctx->pinned_groups, >>>> + group_sched_out_callback, ¶ms); >>> >>> So here I would expect to not iterate events where event->cpu != >>> smp_processor_id() (and ideally not where event->pmu != ctx->pmu). >>> >> >> We still need to iterate thru all groups on thread context switch in >> and out as well as iterate thru cpu == -1 list (software events) additionally >> to smp_processor_id() list from multiplexing timer interrupt handler. > > Well, just doing the @cpu=-1 and @cpu=this_cpu subtrees is less work > than iterating _everything_, right?
Right. That is actually the aim of this whole patch set - to avoid iterating "_everything_".
> > The rest will not survive event_filter_match() anyway, so iterating them > is complete waste of time, and once we have them in a tree, its actually > easy to find this subset. >
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