From fc7bcaf07620dd8f429b1d229b824bc2818406f5 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Tue, 2 Oct 2012 15:41:23 +0200
Subject: [PATCH] --- yaml --- r: 333973 b: refs/heads/master c:
 95cf59ea72331d0093010543b8951bb43f262cac h: refs/heads/master i:   333971:
 83e5486ac23a1e6790f7fd7a6b6772088f1c5c8c v: v3

---
 [refs]                     | 2 +-
 trunk/kernel/events/core.c | 9 ++++++---
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index fb43134db37d..a93a8a5f530e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3f1f33206c16c7b3839d71372bc2ac3f305aa802
+refs/heads/master: 95cf59ea72331d0093010543b8951bb43f262cac
diff --git a/trunk/kernel/events/core.c b/trunk/kernel/events/core.c
index 81939e8999a5..fd15593c7f54 100644
--- a/trunk/kernel/events/core.c
+++ b/trunk/kernel/events/core.c
@@ -372,6 +372,8 @@ void perf_cgroup_switch(struct task_struct *task, int mode)
 
 	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_struct *task, int mode)
 
 			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);