From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f53.google.com (mail-pa0-f53.google.com [209.85.220.53]) by kanga.kvack.org (Postfix) with ESMTP id 833F06B0254 for ; Fri, 18 Sep 2015 13:26:59 -0400 (EDT) Received: by pacex6 with SMTP id ex6so56575934pac.0 for ; Fri, 18 Sep 2015 10:26:59 -0700 (PDT) Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [2001:e42:101:1:202:181:97:72]) by mx.google.com with ESMTPS id fm10si15058622pab.152.2015.09.18.10.26.58 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Fri, 18 Sep 2015 10:26:58 -0700 (PDT) Subject: Re: [PATCH] mm/oom_kill.c: don't kill TASK_UNINTERRUPTIBLE tasks From: Tetsuo Handa References: <1442512783-14719-1-git-send-email-kwalker@redhat.com> <20150917192204.GA2728@redhat.com> <20150918162423.GA18136@redhat.com> In-Reply-To: <20150918162423.GA18136@redhat.com> Message-Id: <201509190139.GJH48908.QMSFJLFtOHOVFO@I-love.SAKURA.ne.jp> Date: Sat, 19 Sep 2015 01:39:53 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: To: oleg@redhat.com, cl@linux.com Cc: kwalker@redhat.com, akpm@linux-foundation.org, mhocko@suse.cz, rientjes@google.com, hannes@cmpxchg.org, vdavydov@parallels.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, skozina@redhat.com Oleg Nesterov wrote: > To simplify the discussion lets ignore PF_FROZEN, this is another issue. > > I am not sure this change is enough, we need to ensure that > select_bad_process() won't pick the same task (or its sub-thread) again. SysRq-f is sometimes unusable because it continues choosing the same thread. oom_kill_process() should not choose a thread which already has TIF_MEMDIE. I think we need to rewrite oom_kill_process(). > > And perhaps something like > > wait_event_timeout(oom_victims_wait, !oom_victims, > configurable_timeout); > > before select_bad_process() makes sense? I think you should not sleep for long with oom_lock mutex held. http://marc.info/?l=linux-mm&m=143031212312459 -- 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