From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 98A6E6001DA for ; Tue, 9 Feb 2010 05:18:39 -0500 (EST) Received: by pzk4 with SMTP id 4so120464pzk.1 for ; Tue, 09 Feb 2010 02:18:38 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <20100205093932.1dcdeb5f.kamezawa.hiroyu@jp.fujitsu.com> <28c262361002050830m7519f1c3y8860540708527fc0@mail.gmail.com> <20100209093246.36c50bae.kamezawa.hiroyu@jp.fujitsu.com> <28c262361002081724l1b64e316v3141fb4567dbf905@mail.gmail.com> <28c262361002090140p37fac1e4q2652e7a4ee3a84d4@mail.gmail.com> Date: Tue, 9 Feb 2010 19:18:38 +0900 Message-ID: <28c262361002090218w62bb49bcp5151f1e8b61af801@mail.gmail.com> Subject: Re: [BUGFIX][PATCH] memcg: fix oom killer kills a task in other cgroup From: Minchan Kim Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: David Rientjes Cc: KAMEZAWA Hiroyuki , "linux-mm@kvack.org" , Balbir Singh , "nishimura@mxp.nes.nec.co.jp" , Andrew Morton List-ID: On Tue, Feb 9, 2010 at 6:55 PM, David Rientjes wrote: > On Tue, 9 Feb 2010, Minchan Kim wrote: > >> My point was following as. >> We try to kill child of OOMed task at first. >> But we can't know any locked state of child when OOM happens. > > We don't need to, child->alloc_lock can be contended in which case we'll > just spin but it won't stay locked because we're out of memory. =C2=A0In = other > words, nothing takes task_lock(child) and then waits for memory to become > available while holding it, that would be fundamentally broken. =C2=A0So = there > is a dependency here and that is that task_lock(current) can't be taken i= n > the page allocator because we'll deadlock in the oom killer, but that > isn't anything new. I understand it so I don't oppose Kame's original patch from now on. :) Thanks for kind explanation. David. --=20 Kind regards, Minchan Kim -- 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