From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 385776B0044 for ; Thu, 8 Jan 2009 19:58:57 -0500 (EST) Message-ID: <4966A117.9030201@cn.fujitsu.com> Date: Fri, 09 Jan 2009 08:57:59 +0800 From: Li Zefan MIME-Version: 1.0 Subject: Re: [RFC][PATCH 1/4] memcg: fix for mem_cgroup_get_reclaim_stat_from_page References: <20090108190818.b663ce20.nishimura@mxp.nes.nec.co.jp> <20090108191430.af89e037.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20090108191430.af89e037.nishimura@mxp.nes.nec.co.jp> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Daisuke Nishimura Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com, balbir@linux.vnet.ibm.com, menage@google.com List-ID: > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index e2996b8..62e69d8 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -559,6 +559,10 @@ mem_cgroup_get_reclaim_stat_from_page(struct page *page) > return NULL; > > pc = lookup_page_cgroup(page); > + smp_rmb(); It is better to add a comment to explain this smp_rmb. I think it's recommended that every memory barrier has a comment. > + if (!PageCgroupUsed(pc)) > + return NULL; > + > mz = page_cgroup_zoneinfo(pc); > if (!mz) > return NULL; > > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org