Cool. Thanks.
On Tue, Oct 2, 2012 at 3:46 PM, Peter Zijlstra <[email protected]> wrote: > On Tue, 2012-10-02 at 15:34 +0200, Stephane Eranian wrote: >> And adding a comment in cgroup_switch() >> >> + /* ensure we process each cpuctx only once */ >> + if (cpuctx->active_pmu != pmu) >> + continue; >> > --- > Subject: perf: Fix perf_cgroup_switch for sw-events > From: Peter Zijlstra <[email protected]> > Date: Tue Oct 02 15:41:23 CEST 2012 > > Jiri reported that he could trigger the WARN_ON_ONCE() in > perf_cgroup_switch() using sw-events. This is because sw-events share > a cpuctx with multiple PMUs. > > Use the ->unique_pmu pointer to limit the pmu iteration to unique > cpuctx instances. > > Reported-and-Tested-by: Jiri Olsa <[email protected]> > Signed-off-by: Peter Zijlstra <[email protected]> > --- > kernel/events/core.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -372,6 +372,8 @@ void perf_cgroup_switch(struct task_stru > > list_for_each_entry_rcu(pmu, &pmus, entry) { > cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); > + if (cpuctx->unique_pmu != pmu) > + continue; /* ensure we process each cpuctx once */ > > /* > * perf_cgroup_events says at least one > @@ -395,9 +397,10 @@ void perf_cgroup_switch(struct task_stru > > if (mode & PERF_CGROUP_SWIN) { > WARN_ON_ONCE(cpuctx->cgrp); > - /* set cgrp before ctxsw in to > - * allow event_filter_match() to not > - * have to pass task around > + /* > + * set cgrp before ctxsw in to allow > + * event_filter_match() to not have to pass > + * task around > */ > cpuctx->cgrp = perf_cgroup_from_task(task); > cpu_ctx_sched_in(cpuctx, EVENT_ALL, task); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
