Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932697Ab0FQIZJ (ORCPT ); Thu, 17 Jun 2010 04:25:09 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:58939 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755655Ab0FQIZG (ORCPT ); Thu, 17 Jun 2010 04:25:06 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Thu, 17 Jun 2010 17:20:34 +0900 From: KAMEZAWA Hiroyuki To: "linux-mm@kvack.org" Cc: "akpm@linux-foundation.org" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" , "linux-kernel@vger.kernel.org" Subject: [BUGFIX][PATCH -mm] fix bad call of memcg_oom_recover at cancel move. Message-Id: <20100617172034.00ea8835.kamezawa.hiroyu@jp.fujitsu.com> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.0.2 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2288 Lines: 59 From: KAMEZAWA Hiroyuki When cgroup_cancel_attach() is called via cgroup_attach_task(), mem_cgroup_clear_mc() can be called even when any migration was done. In such case, mc.to and mc.from is NULL. But, memcg-clean-up-waiting-move-acct-v2.patch doesn't handle this correctly and pass NULL to memcg_oom_recover. fix it. BUG: unable to handle kernel paging request at 000000000000114c IP: [] memcg_oom_recover+0x9/0x30 PGD 61ce4b067 PUD 613ea0067 PMD 0 Oops: 0000 [#1] SMP Call Trace: [] mem_cgroup_clear_mc+0x119/0x1c0 [] mem_cgroup_cancel_attach+0xe/0x10 [] cgroup_attach_task+0x26c/0x2c0 [] cgroup_tasks_write+0x67/0x1c0 [] ? might_fault+0xa5/0xb0 [] ? might_fault+0x5c/0xb0 [] cgroup_file_write+0x2d2/0x330 [] ? print_lock_contention_bug+0x22/0xf0 [] ? security_file_permission+0x1f/0x80 [] vfs_write+0xc8/0x190 [] sys_write+0x51/0x90 [] system_call_fastpath+0x16/0x1b Code: 20 48 39 43 20 41 bc f0 ff ff ff 75 c7 45 88 ae 48 11 00 00 45 31 e4 eb bb 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 0f 1f 44 00 00 <8b> 87 4c 11 00 00 85 c0 75 05 c9 c3 0f 1f 00 48 89 f9 31 d2 be RIP [] memcg_oom_recover+0x9/0x30 Signed-off-by: KAMEZAWA Hiroyuki --- mm/memcontrol.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) Index: mmotm-2.6.35-0611/mm/memcontrol.c =================================================================== --- mmotm-2.6.35-0611.orig/mm/memcontrol.c +++ mmotm-2.6.35-0611/mm/memcontrol.c @@ -4485,8 +4485,10 @@ static void mem_cgroup_clear_mc(void) mc.to = NULL; mc.moving_task = NULL; spin_unlock(&mc.lock); - memcg_oom_recover(from); - memcg_oom_recover(to); + if (from) + memcg_oom_recover(from); + if (to) + memcg_oom_recover(to); wake_up_all(&mc.waitq); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/