From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 579426B003D for ; Sun, 22 Mar 2009 19:11:50 -0400 (EDT) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n2N04vqb015510 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Mon, 23 Mar 2009 09:04:57 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 6F72545DD72 for ; Mon, 23 Mar 2009 09:04:57 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 4D2DF45DE4F for ; Mon, 23 Mar 2009 09:04:57 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 2E28C1DB8038 for ; Mon, 23 Mar 2009 09:04:57 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id CF3F21DB803F for ; Mon, 23 Mar 2009 09:04:56 +0900 (JST) Date: Mon, 23 Mar 2009 09:03:31 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [BUGFIX][PATCH mmotm] memcg: try_get_mem_cgroup_from_swapcache fix Message-Id: <20090323090331.74f085f5.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090323000238.e650c65e.d-nishimura@mtf.biglobe.ne.jp> References: <20090323000238.e650c65e.d-nishimura@mtf.biglobe.ne.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: nishimura@mxp.nes.nec.co.jp Cc: Daisuke Nishimura , Andrew Morton , Balbir Singh , linux-mm List-ID: On Mon, 23 Mar 2009 00:02:38 +0900 Daisuke Nishimura wrote: > From: Daisuke Nishimura > > css_tryget can be called twice in !PageCgroupUsed case. > > Signed-off-by: Daisuke Nishimura Thank you Acked-by: KAMEZAWA Hiroyuki > --- > This is a fix for cgroups-use-css-id-in-swap-cgroup-for-saving-memory-v5.patch > > mm/memcontrol.c | 10 ++++------ > 1 files changed, 4 insertions(+), 6 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 5de6be9..55dea59 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1027,9 +1027,11 @@ static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page) > /* > * Used bit of swapcache is solid under page lock. > */ > - if (PageCgroupUsed(pc)) > + if (PageCgroupUsed(pc)) { > mem = pc->mem_cgroup; > - else { > + if (mem && !css_tryget(&mem->css)) > + mem = NULL; > + } else { > ent.val = page_private(page); > id = lookup_swap_cgroup(ent); > rcu_read_lock(); > @@ -1038,10 +1040,6 @@ static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page) > mem = NULL; > rcu_read_unlock(); > } > - if (!mem) > - return NULL; > - if (!css_tryget(&mem->css)) > - return NULL; > return mem; > } > > > > > -- 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