From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753584Ab1KGWSv (ORCPT ); Mon, 7 Nov 2011 17:18:51 -0500 Received: from cantor2.suse.de ([195.135.220.15]:46085 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751067Ab1KGWSu (ORCPT ); Mon, 7 Nov 2011 17:18:50 -0500 Date: Mon, 7 Nov 2011 23:18:48 +0100 From: Michal Hocko To: David Rientjes Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oleg Nesterov , Ying Han , KOSAKI Motohiro , Andrew Morton Subject: Re: [PATCH] oom: do not kill tasks with oom_score_adj OOM_SCORE_ADJ_MIN Message-ID: <20111107221847.GA7985@tiehlicka.suse.cz> References: <20111104143145.0F93B8B45E@mx2.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 07-11-11 13:54:38, David Rientjes wrote: > On Fri, 4 Nov 2011, Michal Hocko wrote: > > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > > index e916168..4883514 100644 > > --- a/mm/oom_kill.c > > +++ b/mm/oom_kill.c > > @@ -185,6 +185,9 @@ unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem, > > if (!p) > > return 0; > > > > + if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) > > + return 0; > > + > > /* > > * The memory controller may have a limit of 0 bytes, so avoid a divide > > * by zero, if necessary. > > This leaves p locked, you need to do task_unlock(p) first. Yes, right you are. Thanks for spotting this out. > > Once that's fixed, please add my > > Acked-by: David Rientjes Thanks. > and resubmit to Andrew for the 3.2 rc series. Thanks! Andrew, could you push this for 3.2 (bugfix for post 3.1 kernel). --- >>From 10e06e7c0682af58236055ed38bfab58f7935253 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 4 Nov 2011 12:59:44 +0100 Subject: [PATCH] oom: do not kill tasks with oom_score_adj OOM_SCORE_ADJ_MIN To: David Rientjes Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oleg Nesterov , Ying Han , KOSAKI Motohiro , Andrew Morton c9f01245 (oom: remove oom_disable_count) has removed oom_disable_count counter which has been used for early break out from oom_badness so we could never select a task with oom_score_adj set to OOM_SCORE_ADJ_MIN (oom disabled). Now that the counter is gone we are always going through heuristics calculation and we always return a non zero positive value. This means that we can end up killing a task with OOM disabled because it is indistinguishable from regular tasks with 1% resp. CAP_SYS_ADMIN tasks with 3% usage of memory or tasks with oom_score_adj set but OOM enabled. Let's break out early if the task should have OOM disabled. Signed-off-by: Michal Hocko Acked-by: David Rientjes --- mm/oom_kill.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index e916168..4465fb8 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -185,6 +185,11 @@ unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem, if (!p) return 0; + if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { + task_unlock(p); + return 0; + } + /* * The memory controller may have a limit of 0 bytes, so avoid a divide * by zero, if necessary. -- 1.7.7.1 -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic