From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [patch 1/2] cls_cgroup: remove unneeded cgroup_lock Date: Tue, 12 May 2009 13:47:33 -0700 Message-ID: <200905122106.n4CL6ndX009858@imap1.linux-foundation.org> Cc: netdev@vger.kernel.org, akpm@linux-foundation.org, lizf@cn.fujitsu.com, lizf@cn.fujitsuc.com, menage@google.com To: davem@davemloft.net Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:51201 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753004AbZELVK7 (ORCPT ); Tue, 12 May 2009 17:10:59 -0400 Sender: netdev-owner@vger.kernel.org List-ID: From: Li Zefan 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 Acked-by: Paul Menage Signed-off-by: Andrew Morton --- net/sched/cls_cgroup.c | 6 ------ 1 file changed, 6 deletions(-) diff -puN net/sched/cls_cgroup.c~cls_cgroup-remove-unneeded-cgroup_lock net/sched/cls_cgroup.c --- a/net/sched/cls_cgroup.c~cls_cgroup-remove-unneeded-cgroup_lock +++ a/net/sched/cls_cgroup.c @@ -62,13 +62,7 @@ static u64 read_classid(struct cgroup *c 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; } _