From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f43.google.com (mail-wm0-f43.google.com [74.125.82.43]) by kanga.kvack.org (Postfix) with ESMTP id 4B0B66B007E for ; Wed, 23 Mar 2016 08:07:19 -0400 (EDT) Received: by mail-wm0-f43.google.com with SMTP id r129so133024311wmr.1 for ; Wed, 23 Mar 2016 05:07:19 -0700 (PDT) Received: from mail-wm0-f68.google.com (mail-wm0-f68.google.com. [74.125.82.68]) by mx.google.com with ESMTPS id ck9si2750723wjc.88.2016.03.23.05.07.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 23 Mar 2016 05:07:18 -0700 (PDT) Received: by mail-wm0-f68.google.com with SMTP id u125so3712083wmg.0 for ; Wed, 23 Mar 2016 05:07:17 -0700 (PDT) Date: Wed, 23 Mar 2016 13:07:16 +0100 From: Michal Hocko Subject: Re: [PATCH 0/9] oom reaper v6 Message-ID: <20160323120716.GE7059@dhcp22.suse.cz> References: <1458644426-22973-1-git-send-email-mhocko@kernel.org> <201603232011.HDI05246.FFMLtVOHOQJFOS@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201603232011.HDI05246.FFMLtVOHOQJFOS@I-love.SAKURA.ne.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: rientjes@google.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, mingo@elte.hu, hannes@cmpxchg.org, mgorman@suse.de, oleg@redhat.com, a.p.zijlstra@chello.nl, vdavydov@virtuozzo.com On Wed 23-03-16 20:11:35, Tetsuo Handa wrote: > David Rientjes wrote: [...] > > Tetsuo, have you been able to run your previous test cases on top of this > > version and do you have any concerns about it or possible extensions that > > could be made? > > > > I think [PATCH 3/9] [PATCH 4/9] [PATCH 8/9] will be mostly reverted. > My concerns and possible extensions are explained in > > Re: [PATCH 6/5] oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task > http://lkml.kernel.org/r/201603152015.JAE86937.VFOLtQFOFJOSHM@I-love.SAKURA.ne.jp I believe issues you have raised there are a matter for further discussion as they are potential improvements of the existing functionality rather than fixing a regression of the current code. > . Regarding "[PATCH 4/9] mm, oom_reaper: report success/failure", > debug_show_all_locks() may not be safe > > commit 856848737bd944c1 "lockdep: fix debug_show_all_locks()" > commit 82a1fcb90287052a "softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks" Let me ask again. What exactly is unsafe about calling debug_show_all_locks here? It is true that 856848737bd944c1 has changed debug_show_all_locks to ignore running tasks which limits this functionality to some degree but I still think this might be useful. Proposed alternatives were way too verbose and complex on its own. This is something to be further discussed as well, though. > and showing traces might be more useful. > (A discussion for making printk() completely async is in progress.) > > But we don't have time to update this series before merge window for 4.6 closes. > We want to send current patchset as is for now, don't we? So, please go ahead. I am happy that we are on the same patch here. > My other concerns about OOM handling: Let's stick to oom reaper here, please. Thanks! -- 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