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 0C4A46B004D for ; Tue, 18 Aug 2009 16:50:44 -0400 (EDT) Date: Tue, 18 Aug 2009 21:50:50 +0100 From: Mel Gorman Subject: Re: [PATCH 3/3] page-allocator: Move pcp static fields for high and batch off-pcp and onto the zone Message-ID: <20090818205050.GA756@csn.ul.ie> 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> 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 , Nick Piggin , Linux Kernel Mailing List List-ID: On Tue, Aug 18, 2009 at 01:56:22PM -0400, Christoph Lameter wrote: > 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. > They are used in a commonly-used path for allocation so there is some advantage. Put beside pageset, there is no advantage as that structure is already aligned to a cache-line. -- 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