From: Mel Gorman Subject: Re: [PATCH 0/3] Reduce impact to overall system of SLUB using high-order allocations Date: Fri, 13 May 2011 12:24:29 +0100 Message-ID: <20110513112429.GF3569@suse.de> References: <1305127773-10570-1-git-send-email-mgorman@suse.de> <1305149960.2606.53.camel@mulgrave.site> <1305153267.2606.57.camel@mulgrave.site> <20110512180457.GO11579@random.random> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Cc: James Bottomley , David Rientjes , Andrew Morton , Colin King , Raghavendra D Prabhu , Jan Kara , Chris Mason , Christoph Lameter , Pekka Enberg , Rik van Riel , Johannes Weiner , linux-fsdevel , linux-mm , linux-kernel , linux-ext4 To: Andrea Arcangeli Return-path: Received: from cantor2.suse.de ([195.135.220.15]:47927 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932213Ab1EMLYf (ORCPT ); Fri, 13 May 2011 07:24:35 -0400 Content-Disposition: inline In-Reply-To: <20110512180457.GO11579@random.random> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, May 12, 2011 at 08:04:57PM +0200, Andrea Arcangeli wrote: > Hi James! > > On Wed, May 11, 2011 at 05:34:27PM -0500, James Bottomley wrote: > > Yes, but only once in all the testing. With patches 1 and 2 the hang is > > Weird patch 2 makes the large order allocation without ~__GFP_WAIT, so > even COMPACTION=y/n shouldn't matter anymore. Am I misreading > something Mel? > > Removing ~__GFP_WAIT from patch 2 (and adding ~__GFP_REPEAT as a > correctness improvement) and setting COMPACTION=y also should work ok. > should_continue_reclaim could till be looping unless __GFP_REPEAT is cleared if CONFIG_COMPACTION is set. > Removing ~__GFP_WAIT from patch 2 and setting COMPACTION=n is expected > not to work well. > > But compaction should only make the difference if you remove > ~__GFP_WAIT from patch 2. -- Mel Gorman SUSE Labs