From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id BB6E26B008A for ; Fri, 20 Mar 2009 11:29:12 -0400 (EDT) Date: Fri, 20 Mar 2009 15:29:21 +0000 From: Mel Gorman Subject: Re: [PATCH 08/25] Calculate the preferred zone for allocation only once Message-ID: <20090320152921.GN24586@csn.ul.ie> References: <1237543392-11797-1-git-send-email-mel@csn.ul.ie> <1237543392-11797-9-git-send-email-mel@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 11:06:46AM -0400, Christoph Lameter wrote: > On Fri, 20 Mar 2009, Mel Gorman wrote: > > > get_page_from_freelist() can be called multiple times for an allocation. > > Part of this calculates the preferred_zone which is the first usable > > zone in the zonelist. This patch calculates preferred_zone once. > > Isnt this adding an additional pass over the zonelist? Maybe mitigaged by > the first zone usually being the preferred zone. > The alternative is uglifing the iterator quite a bit and making the code a bit impeneratable. The walk to the first preferred zone should be very short. -- 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