Messages in this thread | | | Date | Mon, 30 Oct 2017 11:20:52 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] cgroup, perf_event: Fix perf cgroup hierarchy support |
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On Sat, Oct 28, 2017 at 09:49:37AM -0700, Tejun Heo wrote: > 864c2357ca89 ("perf/core: Do not set cpuctx->cgrp for unscheduled > cgroups") made list_update_cgroup_event() skip setting cpuctx->cgrp if > no cgroup event targets %current's cgroup. This breaks perf_event's > hierarchical support because events which target one of the ancestors > get ignored. > > Fix it by using cgroup_is_descendant() test instead of equality.
Right similar to:
e6a5203399d1 ("perf/core: Fix cgroup time when scheduling descendants")
> Signed-off-by: Tejun Heo <tj@kernel.org> > Fixes: 864c2357ca89 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups") > Cc: stable@vger.kernel.org # v4.9+ > Cc: David Carrillo-Cisneros <davidcc@google.com>
I think David left Google (I've had this email bounce), lets add Stephane.
Cc: Stephane Eranian <eranian@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> --- > kernel/events/core.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 9d93db8..db2e630 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -901,9 +901,12 @@ list_update_cgroup_event(struct perf_event *event, > cpuctx_entry = &cpuctx->cgrp_cpuctx_entry; > /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/ > if (add) { > + struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx); > + > list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list)); > - if (perf_cgroup_from_task(current, ctx) == event->cgrp) > - cpuctx->cgrp = event->cgrp; > + if (cgroup_is_descendant(cgrp->css.cgroup, > + event->cgrp->css.cgroup)) > + cpuctx->cgrp = cgrp; > } else { > list_del(cpuctx_entry); > cpuctx->cgrp = NULL;
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