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 CBA156B007E for ; Tue, 24 Nov 2009 23:08:57 -0500 (EST) Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by e28smtp02.in.ibm.com (8.14.3/8.13.1) with ESMTP id nAP48pNo026899 for ; Wed, 25 Nov 2009 09:38:51 +0530 Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id nAP48ogQ3645548 for ; Wed, 25 Nov 2009 09:38:50 +0530 Received: from d28av03.in.ibm.com (loopback [127.0.0.1]) by d28av03.in.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id nAP48oTt028758 for ; Wed, 25 Nov 2009 15:08:50 +1100 Date: Wed, 25 Nov 2009 09:38:46 +0530 From: Balbir Singh Subject: Re: [BUGFIX][PATCH -stable] memcg: avoid oom-killing innocent task in case of use_hierarchy Message-ID: <20091125040845.GD3365@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <20091124145759.194cfc9f.nishimura@mxp.nes.nec.co.jp> <20091124162854.fb31e81e.nishimura@mxp.nes.nec.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20091124162854.fb31e81e.nishimura@mxp.nes.nec.co.jp> Sender: owner-linux-mm@kvack.org To: Daisuke Nishimura Cc: stable , LKML , linux-mm , Andrew Morton , David Rientjes , KAMEZAWA Hiroyuki , KOSAKI Motohiro List-ID: * nishimura@mxp.nes.nec.co.jp [2009-11-24 16:28:54]: > task_in_mem_cgroup(), which is called by select_bad_process() to check whether > a task can be a candidate for being oom-killed from memcg's limit, checks > "curr->use_hierarchy"("curr" is the mem_cgroup the task belongs to). > > But this check return true(it's false positive) when: > > /00 use_hierarchy == 0 <- hitting limit > /00/aa use_hierarchy == 1 <- "curr" > > This leads to killing an innocent task in 00/aa. This patch is a fix for this > bug. And this patch also fixes the arg for mem_cgroup_print_oom_info(). We > should print information of mem_cgroup which the task being killed, not current, > belongs to. > > Signed-off-by: Daisuke Nishimura > --- > mm/memcontrol.c | 2 +- > mm/oom_kill.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index fd4529d..3acc226 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -496,7 +496,7 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) > task_unlock(task); > if (!curr) > return 0; > - if (curr->use_hierarchy) > + if (mem->use_hierarchy) > ret = css_is_ancestor(&curr->css, &mem->css); > else > ret = (curr == mem); > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > index a7b2460..ed452e9 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -400,7 +400,7 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, > cpuset_print_task_mems_allowed(current); > task_unlock(current); > dump_stack(); > - mem_cgroup_print_oom_info(mem, current); > + mem_cgroup_print_oom_info(mem, p); > show_mem(); > if (sysctl_oom_dump_tasks) > dump_tasks(mem); > Reviewed-by: Balbir Singh -- Balbir -- 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