From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 10DC06B01B5 for ; Sun, 6 Jun 2010 18:34:21 -0400 (EDT) Received: from hpaq11.eem.corp.google.com (hpaq11.eem.corp.google.com [172.25.149.11]) by smtp-out.google.com with ESMTP id o56MYKwC022212 for ; Sun, 6 Jun 2010 15:34:20 -0700 Received: from pvh1 (pvh1.prod.google.com [10.241.210.193]) by hpaq11.eem.corp.google.com with ESMTP id o56MYIjG006547 for ; Sun, 6 Jun 2010 15:34:19 -0700 Received: by pvh1 with SMTP id 1so890241pvh.20 for ; Sun, 06 Jun 2010 15:34:18 -0700 (PDT) Date: Sun, 6 Jun 2010 15:34:15 -0700 (PDT) From: David Rientjes Subject: [patch 04/18] oom: PF_EXITING check should take mm into account In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: Rik van Riel , Nick Piggin , Oleg Nesterov , Balbir Singh , KAMEZAWA Hiroyuki , KOSAKI Motohiro , linux-mm@kvack.org List-ID: From: Oleg Nesterov 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 Signed-off-by: David Rientjes --- mm/oom_kill.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -300,7 +300,7 @@ 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); -- 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