From: Jan Kara Subject: Re: [BUG] fatal hang untarring 90GB file, possibly writeback related. Date: Thu, 28 Apr 2011 15:52:28 +0200 Message-ID: <20110428135228.GC1696@quack.suse.cz> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: James Bottomley , Chris Mason , linux-fsdevel , linux-mm , linux-kernel , linux-ext4 , mgorman@novell.com To: colin.king@canonical.com Return-path: Received: from cantor.suse.de ([195.135.220.2]:56072 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759654Ab1D1Nwa (ORCPT ); Thu, 28 Apr 2011 09:52:30 -0400 Content-Disposition: inline In-Reply-To: <1303990590.2081.9.camel@lenovo> Sender: linux-ext4-owner@vger.kernel.org List-ID: 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... Honza > On Wed, 2011-04-27 at 15:05 -0500, James Bottomley wrote: > > On Wed, 2011-04-27 at 12:50 -0500, James Bottomley wrote: > > > To test the theory, Chris asked me to try with data=ordered. > > > Unfortunately, the deadlock still shows up. This is what I get. > > > > As another data point: I'm trying the same kernel with CONFIG_PREEMPT > > enabled. This time the deadlock doesn't happen. Instead, kswapd0 gets > > pegged at 99% CPU for much of the untar, but it does eventually > > complete. > > > > 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/ > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Jan Kara SUSE Labs, CR