From: James Bottomley Subject: Re: [BUG] fatal hang untarring 90GB file, possibly writeback related. Date: Fri, 06 May 2011 14:14:37 -0500 Message-ID: <1304709277.12427.29.camel@mulgrave.site> References: <20110428171826.GZ4658@suse.de> <1304015436.2598.19.camel@mulgrave.site> <20110428192104.GA4658@suse.de> <1304020767.2598.21.camel@mulgrave.site> <1304025145.2598.24.camel@mulgrave.site> <1304030629.2598.42.camel@mulgrave.site> <20110503091320.GA4542@novell.com> <1304431982.2576.5.camel@mulgrave.site> <1304432553.2576.10.camel@mulgrave.site> <20110506074224.GB6591@suse.de> <20110506154444.GG6591@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Mel Gorman , Jan Kara , colin.king@canonical.com, Chris Mason , linux-fsdevel , linux-mm , linux-kernel , linux-ext4 To: Mel Gorman Return-path: Received: from cantor.suse.de ([195.135.220.2]:43587 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751096Ab1EFTOn (ORCPT ); Fri, 6 May 2011 15:14:43 -0400 In-Reply-To: <20110506154444.GG6591@suse.de> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, 2011-05-06 at 16:44 +0100, Mel Gorman wrote: > Colin and James: Did you happen to switch from SLAB to SLUB between > 2.6.37 and 2.6.38? My own tests were against SLAB which might be why I > didn't see the problem. Am restarting the tests with SLUB. Aargh ... I'm an idiot. I should have thought of SLUB immediately ... it's been causing oopses since debian switched to it. So I recompiled the 2.6.38.4 stable kernel with SLAB instead of SLUB and the problem goes away ... at least from three untar runs on a loaded box ... of course it could manifest a few ms after I send this email ... There are material differences, as well: SLAB isn't taking my system down to very low memory on the untar ... it's keeping about 0.5Gb listed as free. SLUB took that to under 100kb, so it could just be that SLAB isn't wandering as close to the cliff edge? James