From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: [PATCH] fix page_alloc for larger I/O segments (improved) Date: Fri, 14 Dec 2007 13:30:14 -0500 Message-ID: <4762CBB6.5030301@rtr.ca> References: <1197584106.3154.55.camel@localhost.localdomain> <20071213142935.47ff19d9.akpm@linux-foundation.org> <4761B32A.3070201@rtr.ca> <4761BCB4.1060601@rtr.ca> <4761C8E4.2010900@rtr.ca> <4761CE88.9070406@rtr.ca> <20071213163726.3bb601fa.akpm@linux-foundation.org> <4761D160.7060603@rtr.ca> <4761D279.6050500@rtr.ca> <20071214174236.GA28613@csn.ul.ie> <20071214181339.GW26334@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from rtr.ca ([76.10.145.34]:3501 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753325AbXLNSaP (ORCPT ); Fri, 14 Dec 2007 13:30:15 -0500 In-Reply-To: <20071214181339.GW26334@parisc-linux.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Matthew Wilcox Cc: Mel Gorman , Andrew Morton , James.Bottomley@HansenPartnership.com, jens.axboe@oracle.com, lkml@rtr.ca, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-mm@kvack.org Matthew Wilcox wrote: > On Fri, Dec 14, 2007 at 05:42:37PM +0000, Mel Gorman wrote: >> Regrettably this interferes with anti-fragmentation because the "next" page >> on the list on return from rmqueue_bulk is not guaranteed to be of the right >> mobility type. I fixed it as an additional patch but it adds additional cost >> that should not be necessary and it's visible in microbenchmark results on >> at least one machine. > > Is this patch to be preferred to the one Andrew Morton posted to do > list_for_each_entry_reverse? .. This patch replaces my earlier patch that Andrew has: - list_add(&page->lru, list); + list_add_tail(&page->lru, list); Which, in turn, replaced the even-earlier list_for_each_entry_reverse patch. -ml