Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936902AbXFGVWm (ORCPT ); Thu, 7 Jun 2007 17:22:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758791AbXFGVWe (ORCPT ); Thu, 7 Jun 2007 17:22:34 -0400 Received: from terminus.zytor.com ([192.83.249.54]:48198 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755239AbXFGVWe (ORCPT ); Thu, 7 Jun 2007 17:22:34 -0400 Message-ID: <46687598.2040701@zytor.com> Date: Thu, 07 Jun 2007 14:16:08 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.0 (X11/20070419) MIME-Version: 1.0 To: William Lee Irwin III CC: "Robert P. J. Day" , Satyam Sharma , Nick Piggin , Linux Kernel Mailing List , Ralf Baechle Subject: Re: why does the macro "ZERO_PAGE" take an argument? References: <4667EC18.4080904@yahoo.com.au> <4668412D.3030506@zytor.com> <20070607192911.GV6909@holomorphy.com> In-Reply-To: <20070607192911.GV6909@holomorphy.com> X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1034 Lines: 24 William Lee Irwin III wrote: > Robert P. J. Day wrote: >>> although it's not clear where in the source tree are the invocations >>> that would actually make a difference to a MIPS system, which is why >>> i've CC'ed ralf on this. i'm sure he can clear this up. :-) > > On Thu, Jun 07, 2007 at 10:32:29AM -0700, H. Peter Anvin wrote: >> x86 could also benefit from coloured zeropages. In fact, I thought it >> already had them (K8 wants as many as 8.) > > How would one demonstrate the beneficial effect of such? Dean Gaudet at Transmeta did some benchmarking using SPEC. If I recall his numbers correctly (this is from memory, mind you) on Transmeta Efficeon, which has 2-way virtual cache tagging with hardware recovery, zeropage coloring was a 1.5% performance improvement. -hpa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/