From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id 54E4E6B01C1 for ; Mon, 31 May 2010 05:35:43 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o4V9ZeDw029388 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Mon, 31 May 2010 18:35:41 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 8FB4745DE5D for ; Mon, 31 May 2010 18:35:40 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 6CB4245DE4E for ; Mon, 31 May 2010 18:35:40 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 4224E1DB8038 for ; Mon, 31 May 2010 18:35:40 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 023951DB803E for ; Mon, 31 May 2010 18:35:39 +0900 (JST) From: KOSAKI Motohiro Subject: [PATCH 2/5] oom: select_bad_process: PF_EXITING check should take ->mm into account In-Reply-To: <20100531182526.1843.A69D9226@jp.fujitsu.com> References: <20100531182526.1843.A69D9226@jp.fujitsu.com> Message-Id: <20100531183335.1846.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Mon, 31 May 2010 18:35:39 +0900 (JST) Sender: owner-linux-mm@kvack.org To: LKML , linux-mm , Oleg Nesterov , David Rientjes , Andrew Morton , KAMEZAWA Hiroyuki , Nick Piggin Cc: kosaki.motohiro@jp.fujitsu.com List-ID: From: Oleg Nesterov Subject: oom: select_bad_process: PF_EXITING check should take ->mm into account select_bad_process() checks PF_EXITING to detect the task which is going to release its memory, but the logic is very wrong. - a single process P with the dead group leader disables select_bad_process() completely, it will always return ERR_PTR() while P can live forever - if the PF_EXITING task has already released its ->mm it doesn't make sense to expect it is goiing to free more memory (except task_struct/etc) Change the code to ignore the PF_EXITING tasks without ->mm. Signed-off-by: Oleg Nesterov Acked-by: David Rientjes Signed-off-by: KOSAKI Motohiro [rebase to latest -mm] --- mm/oom_kill.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 070b713..c87a6f4 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -287,7 +287,7 @@ static struct task_struct *select_bad_process(unsigned long *ppoints, * the process of exiting and releasing its resources. * Otherwise we could get an easy OOM deadlock. */ - if (p->flags & PF_EXITING) { + if ((p->flags & PF_EXITING) && p->mm) { if (p != current) return ERR_PTR(-1UL); -- 1.6.5.2 -- 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