From: Li Zefan <lizf@cn.fujitsu.com>
Date: Tue, 12 May 2009 10:47:33 +0000 (+0000)
Subject: cls_cgroup: remove unneeded cgroup_lock
X-Git-Tag: v2.6.31-rc1~14^2~511
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=cb1c4b71f6da18fa98bab4af055f391d01bee8ba;p=profile%2Fivi%2Fkernel-x86-ivi.git

cls_cgroup: remove unneeded cgroup_lock

We can remove this lock here, since we are in cgroup write handler and
thus the cgrp is guaranteed to be valid, and no lock is needed when
writing a u32 variable.

Signed-off-by: Li Zefan <lizf@cn.fujitsuc.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 91a3db4..1ab4542 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -62,13 +62,7 @@ static u64 read_classid(struct cgroup *cgrp, struct cftype *cft)
 
 static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value)
 {
-	if (!cgroup_lock_live_group(cgrp))
-		return -ENODEV;
-
 	cgrp_cls_state(cgrp)->classid = (u32) value;
-
-	cgroup_unlock();
-
 	return 0;
 }