From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030240AbVLMVok (ORCPT ); Tue, 13 Dec 2005 16:44:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932506AbVLMVoj (ORCPT ); Tue, 13 Dec 2005 16:44:39 -0500 Received: from omx2-ext.sgi.com ([192.48.171.19]:26584 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S932385AbVLMVoj (ORCPT ); Tue, 13 Dec 2005 16:44:39 -0500 Date: Tue, 13 Dec 2005 13:44:19 -0800 From: Paul Jackson To: Eric Dumazet Cc: akpm@osdl.org, linux-kernel@vger.kernel.org, nickpiggin@yahoo.com.au, Simon.Derr@bull.net, ak@suse.de, clameter@sgi.com Subject: Re: [PATCH] Cpuset: rcu optimization of page alloc hook Message-Id: <20051213134419.175821cd.pj@sgi.com> In-Reply-To: <439EF75D.50206@cosmosbay.com> References: <20051211233130.18000.2748.sendpatchset@jackhammer.engr.sgi.com> <439D39A8.1020806@cosmosbay.com> <20051212020211.1394bc17.pj@sgi.com> <20051212021247.388385da.akpm@osdl.org> <20051213075345.c39f335d.pj@sgi.com> <439EF75D.50206@cosmosbay.com> Organization: SGI X-Mailer: Sylpheed version 2.1.7 (GTK+ 2.4.9; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Eric wrote: > I do think we should have defined a special section for very hot (and written) > spots. It's more easy to locate thos hot spots than 'mostly read and shared by > all cpus without cache ping pongs' places... Should we do something like: 1) identify the hot write spots, to arrange them by access pattern, as Christoph considered, in another reply on this thread. 2) identify the hot read, cold write spots, to bunch them up away from (1) 3) leave the rest as "inert filler" (aka "cannon fodder", in my previous reply), but unmarked in any case. 4) change the word "__read_mostly" to "__hot_read_cold_write", to more accurately fit item (2). -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.925.600.0401