From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Date: Fri, 25 Sep 2009 05:54:01 +0000 (+0800)
Subject: perf_event: Clean up perf_event_init_task()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=27f9994c50e95f3a5a81fe4c7491a9f9cffe6ec0;p=linux-beck.git

perf_event: Clean up perf_event_init_task()

While at it: we can traverse ctx->group_list to get all
group leader, it should be safe since we hold ctx->mutex.

Changlog v1->v2:

  - remove WARN_ON_ONCE() according to Peter Zijlstra's suggestion

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <4ABC5AF9.6060808@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index e50543db642a..e491fb087939 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4767,9 +4767,7 @@ int perf_event_init_task(struct task_struct *child)
 	 * We dont have to disable NMIs - we are only looking at
 	 * the list, not manipulating it:
 	 */
-	list_for_each_entry_rcu(event, &parent_ctx->event_list, event_entry) {
-		if (event != event->group_leader)
-			continue;
+	list_for_each_entry(event, &parent_ctx->group_list, group_entry) {
 
 		if (!event->attr.inherit) {
 			inherited_all = 0;