From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id 77AF26B01CC for ; Tue, 1 Jun 2010 14:59:31 -0400 (EDT) Received: from wpaz13.hot.corp.google.com (wpaz13.hot.corp.google.com [172.24.198.77]) by smtp-out.google.com with ESMTP id o51IxTBE003093 for ; Tue, 1 Jun 2010 11:59:29 -0700 Received: from pxi12 (pxi12.prod.google.com [10.243.27.12]) by wpaz13.hot.corp.google.com with ESMTP id o51IxR2q023225 for ; Tue, 1 Jun 2010 11:59:28 -0700 Received: by pxi12 with SMTP id 12so5742805pxi.0 for ; Tue, 01 Jun 2010 11:59:27 -0700 (PDT) Date: Tue, 1 Jun 2010 11:59:24 -0700 (PDT) From: David Rientjes Subject: Re: [patch -mm 13/18] oom: avoid race for oom killed tasks detaching mm prior to exit In-Reply-To: <20100601164026.2472.A69D9226@jp.fujitsu.com> Message-ID: References: <20100601164026.2472.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Andrew Morton , Rik van Riel , Nick Piggin , Oleg Nesterov , KAMEZAWA Hiroyuki , Balbir Singh , linux-mm@kvack.org List-ID: On Tue, 1 Jun 2010, KOSAKI Motohiro wrote: > > Tasks detach its ->mm prior to exiting so it's possible that in progress > > oom kills or already exiting tasks may be missed during the oom killer's > > tasklist scan. When an eligible task is found with either TIF_MEMDIE or > > PF_EXITING set, the oom killer is supposed to be a no-op to avoid > > needlessly killing additional tasks. This closes the race between a task > > detaching its ->mm and being removed from the tasklist. > > > > Out of memory conditions as the result of memory controllers will > > automatically filter tasks that have detached their ->mm (since > > task_in_mem_cgroup() will return 0). This is acceptable, however, since > > memcg constrained ooms aren't the result of a lack of memory resources but > > rather a limit imposed by userspace that requires a task be killed > > regardless. > > > > [oleg@redhat.com: fix PF_EXITING check for !p->mm tasks] > > Acked-by: Nick Piggin > > Signed-off-by: David Rientjes > > need respin. > No, it applies to mmotm-2010-05-21-16-05 as all of these patches do. I know you've pushed Oleg's patches but they are also included here so no respin is necessary unless they are merged first (and I think that should only happen if Andrew considers them to be rc material). I'll base my patchsets on the -mm tree. -- 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