Messages in this thread | | | Date | Wed, 4 Jan 2012 23:02:42 +0000 | Subject | Re: perf_events: proposed fix for broken intr throttling (repost) | From | Stephane Eranian <> |
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On Wed, Jan 4, 2012 at 10:49 PM, Peter Zijlstra <peterz@infradead.org> wrote: > On Wed, 2012-01-04 at 21:33 +0000, Stephane Eranian wrote: >> > I don't think it needs that, I do dislike the unconditional iterate all >> > events thing though. Maybe we can set some per-cpu state indicating >> > someone got throttled (rare under normal operation -- you'd hope) and >> > only iterate to unthrottle when we find this set. >> > >> Could try that too. >> >> > I think the event scheduling resulting from migration will already >> > re-enable the event, avoiding the loss of unthrottle due to that.. >> > although it would be good to verify that. >> > >> Yes, you're not dead forever, but still it is not acceptable as is. > > Oh for sure, I didn't mean it like that. What I was getting at is a > counter getting throttled on one cpu, setting the per-cpu variable, > getting migrated and not getting unthrottled due to now living on > another cpu which doesn't have the per-cpu thing set. > Yes, that is true. I think that throttled counter needs to live in ctx and not per-cpu.
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