From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759392AbZHRR43 (ORCPT ); Tue, 18 Aug 2009 13:56:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758833AbZHRR43 (ORCPT ); Tue, 18 Aug 2009 13:56:29 -0400 Received: from smtp3.ultrahosting.com ([74.213.175.254]:49197 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758794AbZHRR42 (ORCPT ); Tue, 18 Aug 2009 13:56:28 -0400 Date: Tue, 18 Aug 2009 13:56:22 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Mel Gorman cc: Linux Memory Management List , Nick Piggin , Linux Kernel Mailing List Subject: Re: [PATCH 3/3] page-allocator: Move pcp static fields for high and batch off-pcp and onto the zone In-Reply-To: <20090818164216.GA13435@csn.ul.ie> Message-ID: References: <1250594162-17322-1-git-send-email-mel@csn.ul.ie> <1250594162-17322-4-git-send-email-mel@csn.ul.ie> <20090818164216.GA13435@csn.ul.ie> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 18 Aug 2009, Mel Gorman wrote: > On Tue, Aug 18, 2009 at 10:18:48AM -0400, Christoph Lameter wrote: > > > > This will increase the cache footprint for the hot code path. Could these > > new variable be moved next to zone fields that are already in use there? > > The pageset array is used f.e. > > > > pageset is ____cacheline_aligned_in_smp so putting pcp->high/batch near > it won't help in terms of cache footprint. This is why I located it near > watermarks because it's known they'll be needed at roughly the same time > pcp->high/batch would be normally accessed. watermarks are not accessed from the hot code path in free_hot_cold page.