perf: Fix the missing event initialization when pmu is found in idr

Lin Ming · Ingo Molnar · commit 940c5b2971de · 2011-03-04T11:32:50.000+01:00
Currently, the event is not initialized if pmu is found in idr. This
never causes bug just because now no pmu is associated with the idr
id.

Signed-off-by: Lin Ming &lt;ming.m.lin@intel.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
LKML-Reference: &lt;1298812411.2699.9.camel@localhost&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
@@ -6098,17 +6098,22 @@ struct pmu *perf_init_event(struct perf_event *event)
 {
 	struct pmu *pmu = NULL;
 	int idx;
+	int ret;
 
 	idx = srcu_read_lock(&pmus_srcu);
 
 	rcu_read_lock();
 	pmu = idr_find(&pmu_idr, event->attr.type);
 	rcu_read_unlock();
-	if (pmu)
+	if (pmu) {
+		ret = pmu->event_init(event);
+		if (ret)
+			pmu = ERR_PTR(ret);
 		goto unlock;
+	}
 
 	list_for_each_entry_rcu(pmu, &pmus, entry) {
-		int ret = pmu->event_init(event);
+		ret = pmu->event_init(event);
 		if (!ret)
 			goto unlock;
 
