Messages in this thread | | | Subject | Re: [PATCH] perf_events: improve x86 event scheduling (v5) | From | Peter Zijlstra <> | Date | Thu, 21 Jan 2010 11:11:52 +0100 |
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On Thu, 2010-01-21 at 11:08 +0100, Stephane Eranian wrote: > >> > Do you mean this: > >> > > >> > hw_perf_group_sched_in_begin(&x86_pmu); > >> > > >> > for_each_event(event, group) { > >> > event->enable(); //do the collection here > >> > } > >> > > >> > > >> > if (hw_perf_group_sched_in_end(&x86_pmu)) { > >> > rollback... > >> > } > >> > > >> > That requires to know in advance if we have hardware pmu > >> > in the list though (can be a flag in the group). > >> > > I don't think this model can work without scheduling for each event. > > Imagine the situation where you have more events than you have > counters. At each tick you:
No it wont indeed, but it will work for where we now use hw_perf_group_sched_in() without having to replicate lots of code.
For the cases you mention I see no other way than to try and schedule each event individually.
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