Commit-ID: 8fc31ce8896fc3cea1d79688c8ff950ad4e73afe
Gitweb: http://git.kernel.org/tip/8fc31ce8896fc3cea1d79688c8ff950ad4e73afe
Author: David Carrillo-Cisneros <davi...@google.com>
AuthorDate: Sun, 4 Dec 2016 00:46:17 -0800
Committer: Ingo Molnar <mi...@kernel.org>
CommitDate: Tue, 6 Dec 2016 09:44:29 +0100
perf/core: Remove invalid warning from list_update_cgroup_even()t
The warning introduced in commit:
864c2357ca89 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups")
assumed that a cgroup switch always precedes list_del_event. This is
not the case. Remove warning.
Make sure that cpuctx->cgrp is NULL until a cgroup event is sched in
or ctx->nr_cgroups == 0.
Signed-off-by: David Carrillo-Cisneros <davi...@google.com>
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Cc: Alexander Shishkin <alexander.shish...@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Borislav Petkov <b...@suse.de>
Cc: Fenghua Yu <fenghua...@intel.com>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Kan Liang <kan.li...@intel.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Marcelo Tosatti <mtosa...@redhat.com>
Cc: Nilay Vaish <nilayva...@gmail.com>
Cc: Paul Turner <p...@google.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Ravi V Shankar <ravi.v.shan...@intel.com>
Cc: Stephane Eranian <eran...@google.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Vegard Nossum <vegard.nos...@gmail.com>
Cc: Vikas Shivappa <vikas.shiva...@linux.intel.com>
Cc: Vince Weaver <vincent.wea...@maine.edu>
Link:
http://lkml.kernel.org/r/1480841177-27299-1-git-send-email-davi...@google.com
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
kernel/events/core.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 6ee1feb..02c8421 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -903,17 +903,14 @@ list_update_cgroup_event(struct perf_event *event,
*/
cpuctx = __get_cpu_context(ctx);
- /* Only set/clear cpuctx->cgrp if current task uses event->cgrp. */
- if (perf_cgroup_from_task(current, ctx) != event->cgrp) {
- /*
- * We are removing the last cpu event in this context.
- * If that event is not active in this cpu, cpuctx->cgrp
- * should've been cleared by perf_cgroup_switch.
- */
- WARN_ON_ONCE(!add && cpuctx->cgrp);
- return;
- }
- cpuctx->cgrp = add ? event->cgrp : NULL;
+ /*
+ * cpuctx->cgrp is NULL until a cgroup event is sched in or
+ * ctx->nr_cgroup == 0 .
+ */
+ if (add && perf_cgroup_from_task(current, ctx) == event->cgrp)
+ cpuctx->cgrp = event->cgrp;
+ else if (!add)
+ cpuctx->cgrp = NULL;
}
#else /* !CONFIG_CGROUP_PERF */
