Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261360AbVC0ScQ (ORCPT ); Sun, 27 Mar 2005 13:32:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261379AbVC0ScQ (ORCPT ); Sun, 27 Mar 2005 13:32:16 -0500 Received: from dsl027-180-174.sfo1.dsl.speakeasy.net ([216.27.180.174]:60615 "EHLO cheetah.davemloft.net") by vger.kernel.org with ESMTP id S261360AbVC0ScK (ORCPT ); Sun, 27 Mar 2005 13:32:10 -0500 Date: Sun, 27 Mar 2005 10:23:13 -0800 From: "David S. Miller" To: Andi Kleen Cc: davidm@hpl.hp.com, clameter@sgi.com, vda@port.imtp.ilyichevsk.odessa.ua, haveblue@us.ibm.com, akpm@osdl.org, linux-kernel@vger.kernel.org, mel@csn.ul.ie, linux-ia64@vger.kernel.org, Jens.Maurer@gmx.net Subject: Re: [PATCH] add a clear_pages function to clear pages of higher order Message-Id: <20050327102313.04498cdc.davem@davemloft.net> In-Reply-To: <20050327171220.GA18506@muc.de> References: <200503111008.12134.vda@port.imtp.ilyichevsk.odessa.ua> <200503181154.37414.vda@port.imtp.ilyichevsk.odessa.ua> <20050318192808.GB38053@muc.de> <16963.2075.713737.485070@napali.hpl.hp.com> <20050327171220.GA18506@muc.de> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; sparc-unknown-linux-gnu) X-Face: "_;p5u5aPsO,_Vsx"^v-pEq09'CU4&Dc1$fQExov$62l60cgCc%FnIwD=.UF^a>?5'9Kn[;433QFVV9M..2eN.@4ZWPGbdi<=?[:T>y?SD(R*-3It"Vj:)"dP 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 Content-Length: 986 Lines: 26 On 27 Mar 2005 19:12:20 +0200 Andi Kleen wrote: > With non temporal stores > you guarantee at least one hard cache miss directly after > the return to user space. This is true if the cacheline were not present already at the time of the non-temporal store. I know what you're trying to say, I'm just clarifying. The real question is if a large enough ratio of those cachelines in the page get similarly accessed. I happen to think the answer to that for any real example is yes. Yet, I have no way to prove this. It would be cool to do some hacks under Xen or user-mode Linux to get some real statistics about this. Actually, this could be done also with hacks to valgrind or other similar tools. QEMU could also be used. - 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/