From: Michal Hocko Subject: Re: Lockup in wait_transaction_locked under memory pressure Date: Thu, 25 Jun 2015 15:58:59 +0200 Message-ID: <20150625135859.GH17237@dhcp22.suse.cz> References: <558BD447.1010503@kyup.com> <558BD507.9070002@kyup.com> <20150625112116.GC17237@dhcp22.suse.cz> <558BE96E.7080101@kyup.com> <20150625115025.GD17237@dhcp22.suse.cz> <558C023B.1040204@kyup.com> <20150625134558.GF17237@dhcp22.suse.cz> <558C080F.7040104@kyup.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, Marian Marinov To: Nikolay Borisov Return-path: Received: from cantor2.suse.de ([195.135.220.15]:51021 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751751AbbFYN7A (ORCPT ); Thu, 25 Jun 2015 09:59:00 -0400 Content-Disposition: inline In-Reply-To: <558C080F.7040104@kyup.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu 25-06-15 16:54:23, Nikolay Borisov wrote: > > > On 06/25/2015 04:45 PM, Michal Hocko wrote: [...] > > memcg oom killer ignores oom_kill_allocating_task so the victim might be > > different from the current task. That means the victim might get stuck > > behind a lock held by somebody else. If the ext4 journaling code depends > > on memcg charges and retry endlessly then the waiters would get stuck as > > well. > > I've patched the cgroup OOM so that it takes into account the > oom_kill_allocating_task. I am not very much keen on this configuration because it behaves very randomly and I am pretty sure it will just paper over the real issue here. -- Michal Hocko SUSE Labs