From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 15E036B0055 for ; Fri, 20 Mar 2009 12:26:14 -0400 (EDT) Date: Fri, 20 Mar 2009 16:27:16 +0000 From: Mel Gorman Subject: Re: [PATCH 00/25] Cleanup and optimise the page allocator V5 Message-ID: <20090320162716.GP24586@csn.ul.ie> References: <1237543392-11797-1-git-send-email-mel@csn.ul.ie> <20090320153723.GO24586@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: Linux Memory Management List , KOSAKI Motohiro , Nick Piggin , Linux Kernel Mailing List , Lin Ming , Zhang Yanmin , Peter Zijlstra , Andrew Morton List-ID: On Fri, Mar 20, 2009 at 12:07:22PM -0400, Christoph Lameter wrote: > On Fri, 20 Mar 2009, Mel Gorman wrote: > > > good idea one way or the other. Course, this meant a search of the PCP > > lists or increasing the size of the PCP structure - swings and > > roundabouts :/ > > The PCP list structure irks me a bit. Manipulating doubly linked lists > means touching at least 3 cachelines. Yeah, and bloats the structure quite a bit. It's what hits the one-list-per-migratetype the hardest. > Is it possible to go to a simple > linked list (one cacheline to be touched)? I considered it but it breaks the hot/cold allocation/freeing logic and the search code became weird enough looking fast enough that I dropped it. > Or an array of pointers to > pages instead (one cacheline may contian multiple pointers to pcp pages > which means multiple pages could be handled with a single cacheline)? > An array of pointers is promising but it would bloat the structure quiet a bit too. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org