Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760545Ab1D1OZa (ORCPT ); Thu, 28 Apr 2011 10:25:30 -0400 Received: from cantor.suse.de ([195.135.220.2]:57102 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932534Ab1D1OZU (ORCPT ); Thu, 28 Apr 2011 10:25:20 -0400 Subject: Re: [BUG] fatal hang untarring 90GB file, possibly writeback related. From: James Bottomley To: Mel Gorman Cc: Jan Kara , colin.king@canonical.com, Chris Mason , linux-fsdevel , linux-mm , linux-kernel , linux-ext4 , mgorman@novell.com In-Reply-To: <20110428140725.GX4658@suse.de> References: <1303920553.2583.7.camel@mulgrave.site> <1303921583-sup-4021@think> <1303923000.2583.8.camel@mulgrave.site> <1303923177-sup-2603@think> <1303924902.2583.13.camel@mulgrave.site> <1303925374-sup-7968@think> <1303926637.2583.17.camel@mulgrave.site> <1303934716.2583.22.camel@mulgrave.site> <1303990590.2081.9.camel@lenovo> <20110428135228.GC1696@quack.suse.cz> <20110428140725.GX4658@suse.de> Content-Type: text/plain; charset="UTF-8" Date: Thu, 28 Apr 2011 09:25:14 -0500 Message-ID: <1304000714.2598.0.camel@mulgrave.site> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1421 Lines: 34 On Thu, 2011-04-28 at 15:07 +0100, Mel Gorman wrote: > On Thu, Apr 28, 2011 at 03:52:28PM +0200, Jan Kara wrote: > > On Thu 28-04-11 12:36:30, Colin Ian King wrote: > > > One more data point to add, I've been looking at an identical issue when > > > copying large amounts of data. I bisected this - and the lockups occur > > > with commit > > > 3e7d344970673c5334cf7b5bb27c8c0942b06126 - before that I don't see the > > > issue. With this commit, my file copy test locks up after ~8-10 > > > iterations, before this commit I can copy > 100 times and don't see the > > > lockup. > > Adding Mel to CC, I guess he'll be interested. Mel, it seems this commit > > of yours causes kswapd on non-preempt kernels spin for a *long* time... > > > > I'm still thinking about the traces which do not point the finger > directly at compaction per-se but it's possible that the change means > kswapd is not reclaiming like it should be. > > To test this theory, does applying > [d527caf2: mm: compaction: prevent kswapd compacting memory to reduce > CPU usage] help? I can answer definitively no to this. The upstream kernel I reproduced this on has that patch included. James -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/