Messages in this thread | | | Date | Thu, 3 Nov 2011 09:41:04 +0200 | From | Gleb Natapov <> | Subject | Re: [PATCH] perf: do not set task_ctx pointer in cpuctx if there is no events in the context |
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Ingo, Peter can you look into this please.
On Sun, Oct 23, 2011 at 07:10:33PM +0200, Gleb Natapov wrote: > Do not set task_ctx pointer during sched_in if there is no > events associated with the context. Otherwise if during task > execution total number of events in the system will become zero > perf_event_context_sched_out() will not be called and cpuctx->task_ctx > will be left with a stale value. > > Signed-off-by: Gleb Natapov <gleb@redhat.com> > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 0f85778..68b13ee 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -2172,7 +2172,8 @@ static void perf_event_context_sched_in(struct perf_event_context *ctx, > > perf_event_sched_in(cpuctx, ctx, task); > > - cpuctx->task_ctx = ctx; > + if (ctx->nr_events) > + cpuctx->task_ctx = ctx; > > perf_pmu_enable(ctx->pmu); > perf_ctx_unlock(cpuctx, ctx); > -- > Gleb. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
-- Gleb.
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