From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f51.google.com (mail-wm0-f51.google.com [74.125.82.51]) by kanga.kvack.org (Postfix) with ESMTP id 49DA96B0005 for ; Wed, 17 Feb 2016 09:48:37 -0500 (EST) Received: by mail-wm0-f51.google.com with SMTP id g62so240601363wme.0 for ; Wed, 17 Feb 2016 06:48:37 -0800 (PST) Received: from mail-wm0-f49.google.com (mail-wm0-f49.google.com. [74.125.82.49]) by mx.google.com with ESMTPS id m3si4931382wmb.52.2016.02.17.06.48.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 17 Feb 2016 06:48:36 -0800 (PST) Received: by mail-wm0-f49.google.com with SMTP id a4so31492995wme.1 for ; Wed, 17 Feb 2016 06:48:35 -0800 (PST) Date: Wed, 17 Feb 2016 15:48:34 +0100 From: Michal Hocko Subject: Re: [PATCH v2] mm,oom: exclude oom_task_origin processes if they are OOM-unkillable. Message-ID: <20160217144834.GQ29196@dhcp22.suse.cz> References: <1455719460-7690-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1455719460-7690-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: akpm@linux-foundation.org, rientjes@google.com, mgorman@suse.de, oleg@redhat.com, torvalds@linux-foundation.org, hughd@google.com, andrea@kernel.org, riel@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Wed 17-02-16 23:31:00, Tetsuo Handa wrote: > oom_scan_process_thread() returns OOM_SCAN_SELECT when there is a > thread which returns oom_task_origin() == true. But it is possible > that such thread is marked as OOM-unkillable. In that case, the OOM > killer must not select such process. As already pointed out swapoff or ksm run_store are the only users of OOM_FLAG_ORIGIN and it would be insane to run them from an oom disabled context. So I wouldn't care much about this part that much and consider the patch to be more of a cleanup rather than a bug fix. > Since it is meaningless to return OOM_SCAN_OK for OOM-unkillable > process because subsequent oom_badness() call will return 0, this > patch changes oom_scan_process_thread to return OOM_SCAN_CONTINUE > if that process is marked as OOM-unkillable (regardless of > oom_task_origin()). > > Signed-off-by: Tetsuo Handa > Suggested-by: Michal Hocko Acked-by: Michal Hocko > --- > mm/oom_kill.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > index 7653055..cf87153 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -282,7 +282,7 @@ enum oom_scan_t oom_scan_process_thread(struct oom_control *oc, > if (!is_sysrq_oom(oc)) > return OOM_SCAN_ABORT; > } > - if (!task->mm) > + if (!task->mm || task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) > return OOM_SCAN_CONTINUE; > > /* > -- > 1.8.3.1 -- Michal Hocko SUSE Labs -- 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