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| author | Tejun Heo <tj@kernel.org> | 2017-10-28 09:49:37 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-10-30 11:58:51 +0100 |
| commit | be96b316deff35e119760982c43af74e606fa143 (patch) | |
| tree | 0751806ebea8af27293e0892843e06e21a5d97f0 /kernel/events | |
| parent | 4139433c9a81a6ee21e5293989122c203a14a6d8 (diff) | |
| download | lwn-be96b316deff35e119760982c43af74e606fa143.tar.gz lwn-be96b316deff35e119760982c43af74e606fa143.zip | |
perf/cgroup: Fix perf cgroup hierarchy support
The following commit:
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.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-team@fb.com
Cc: stable@vger.kernel.org # v4.9+
Fixes: 864c2357ca89 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups")
Link: http://lkml.kernel.org/r/20171028164237.GA972780@devbig577.frc2.facebook.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 9d93db81fa36..10cdb9c26b5d 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -901,9 +901,11 @@ 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; |