From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755327AbYLAMPU (ORCPT ); Mon, 1 Dec 2008 07:15:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750770AbYLAMPF (ORCPT ); Mon, 1 Dec 2008 07:15:05 -0500 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:43350 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751084AbYLAMPD (ORCPT ); Mon, 1 Dec 2008 07:15:03 -0500 From: KOSAKI Motohiro To: LKML , linux-mm , Andrew Morton , Balbir Singh , KAMEZAWA Hiroyuki , Rik van Riel Subject: [PATCH 05/11] memcg: add null check to page_cgroup_zoneinfo() Cc: kosaki.motohiro@jp.fujitsu.com In-Reply-To: <20081201205810.1CCA.KOSAKI.MOTOHIRO@jp.fujitsu.com> References: <20081201205810.1CCA.KOSAKI.MOTOHIRO@jp.fujitsu.com> Message-Id: <20081201211424.1CD9.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.42 [ja] Date: Mon, 1 Dec 2008 21:14:59 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org if CONFIG_CGROUP_MEM_RES_CTLR_SWAP=y, page_cgroup::mem_cgroup can be NULL. Therefore null checking is better. latter patch use this function. Signed-off-by: KOSAKI Motohiro --- mm/memcontrol.c | 3 +++ 1 file changed, 3 insertions(+) Index: b/mm/memcontrol.c =================================================================== --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -231,6 +231,9 @@ page_cgroup_zoneinfo(struct page_cgroup int nid = page_cgroup_nid(pc); int zid = page_cgroup_zid(pc); + if (!mem) + return NULL; + return mem_cgroup_zoneinfo(mem, nid, zid); }