From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264881AbTL0Xui (ORCPT ); Sat, 27 Dec 2003 18:50:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264883AbTL0Xui (ORCPT ); Sat, 27 Dec 2003 18:50:38 -0500 Received: from holomorphy.com ([199.26.172.102]:52912 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S264881AbTL0Xuh (ORCPT ); Sat, 27 Dec 2003 18:50:37 -0500 Date: Sat, 27 Dec 2003 15:50:16 -0800 From: William Lee Irwin III To: "Eric W. Biederman" Cc: Linus Torvalds , Anton Ertl , linux-kernel@vger.kernel.org Subject: Re: Page Colouring (was: 2.6.0 Huge pages not working as expected) Message-ID: <20031227235016.GB22503@holomorphy.com> Mail-Followup-To: William Lee Irwin III , "Eric W. Biederman" , Linus Torvalds , Anton Ertl , linux-kernel@vger.kernel.org References: <179fV-1iK-23@gated-at.bofh.it> <179IS-1VD-13@gated-at.bofh.it> <2003Dec27.212103@a0.complang.tuwien.ac.at> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds writes: >> Basically: prove me wrong. People have tried before. They have failed. >> Maybe you'll succeed. I doubt it, but hey, I'm not stopping you. On Sat, Dec 27, 2003 at 04:31:22PM -0700, Eric W. Biederman wrote: > For anyone taking you up on this I'd like to suggest two possible > directions. > 1) Increasing PAGE_SIZE in the kernel. > 2) Creating zones for the different colors. Zones were not > implemented last time, this was tried. > Both of those should be minimal impact to the complexity > of the current kernel. > I don't know where we will wind up but the performance variation's > caused by cache conflicts in today's applications are real, and easily > measurable. Giving the growing increase in performance difference > between CPUs and memory Amdahl's Law shows this will only grow > so I think this is worth looking at. Increasing PAGE_SIZE in the kernel either (a) breaks ABI or (b) is nontrivial. I suppose I should try some of the page coloring benchmarks on pgcl (which preserves ABI). -- wli