From: Theodore Ts'o Subject: Re: Call trace in ext4_es_lru_add on 3.10 stable Date: Mon, 22 Sep 2014 16:20:04 -0400 Message-ID: <20140922202004.GF4572@thunk.org> References: <541AD93A.70203@profihost.ag> <20140918192131.GD19520@thunk.org> <541B32A1.3080706@profihost.ag> <20140918194311.GE19520@thunk.org> <541FC817.7030401@profihost.ag> <20140922164715.GB4572@thunk.org> <54206AA2.1050607@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, "p.herz@profihost.ag >> Philipp Herz - Profihost AG" , stable@vger.kernel.org To: Stefan Priebe Return-path: Received: from imap.thunk.org ([74.207.234.97]:41659 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752760AbaIVUUI (ORCPT ); Mon, 22 Sep 2014 16:20:08 -0400 Content-Disposition: inline In-Reply-To: <54206AA2.1050607@profihost.ag> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Sep 22, 2014 at 08:29:54PM +0200, Stefan Priebe wrote: > Hi, > Am 22.09.2014 18:47, schrieb Theodore Ts'o: > >On Mon, Sep 22, 2014 at 08:56:23AM +0200, Stefan Priebe wrote: > >>>That's not the whole message; you just weren't able to capture it all. > >>>How are you capturing these messages, by the way? Serial console? > >> > >>Sorry this was an incomplete copy and paste by me. > >> > >>Here is the complete output: > >>[1578544.839610] BUG: soft lockup - CPU#7 stuck for 22s! [mysqld:29281] > >>[1578544.893450] Modules linked in: nf_conntrack_ipv4 nf_defrag_ipv4 > > > >OK, thanks, this is a known bug, where when ext4 is under heavy memory > >pressure, we can end up stalling in reclaim. This message indicates > >that the system got stalled for 22 seconds, which is not good, since > >it impacts the interactivity of your system, and increases the > >long-tail latency of requests to servers running on your system, but > >it doesn't cause any data loss or will cause any of your processes to > >crash or otherwise stop functioning (except for temporarily). > > > >It's something that we are working on, and there are patches which > >Zheng Liu submitted that still need a bit of polishing, but I hope to > >have it addressed soon. > > Thanks for your feedback. Will those patches go to stable? Any link to > those patches? I'm not sure they will go to Stable when they are ready, because the patches are somewhat complex and so they may not apply cleanly to much older kernels. The patches under discussion (some have been applied, others hae been waiting for some requested changes) can be found here: http://patchwork.ozlabs.org/patch/377720 http://patchwork.ozlabs.org/patch/377721 http://patchwork.ozlabs.org/patch/377722 http://patchwork.ozlabs.org/patch/377723 http://patchwork.ozlabs.org/patch/377724 http://patchwork.ozlabs.org/patch/377725 http://patchwork.ozlabs.org/patch/377727 - Ted