From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268132AbUHQH2Y (ORCPT ); Tue, 17 Aug 2004 03:28:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268133AbUHQH2Y (ORCPT ); Tue, 17 Aug 2004 03:28:24 -0400 Received: from mx1.redhat.com ([66.187.233.31]:662 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S268132AbUHQH2W (ORCPT ); Tue, 17 Aug 2004 03:28:22 -0400 Subject: Re: [PATCH] Use x86 SSE instructions for clear_page, copy_page From: Arjan van de Ven Reply-To: arjanv@redhat.com To: Jens Maurer Cc: Linux Kernel In-Reply-To: <4121A211.8080902@gmx.net> References: <4121A211.8080902@gmx.net> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-dxOrFj0RXcoKEdIGcQec" Organization: Red Hat UK Message-Id: <1092727670.2792.4.camel@laptop.fenrus.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Tue, 17 Aug 2004 09:27:51 +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --=-dxOrFj0RXcoKEdIGcQec Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, 2004-08-17 at 08:13, Jens Maurer wrote: > The attached patch (against kernel 2.6.8.1) enables using SSE > instructions for copy_page and clear_page. >=20 > A user-space test on my Pentium III 850 MHz shows a 3x speedup for > clear_page (compared to the default "rep stosl"), and a 50% speedup > for copy_page (compared to the default "rep movsl"). For a Pentium-4, > the speedup is about 50% in both the clear_page and copy_page cases. we used to have code like this in 2.4 but it got removed: the non temperal store code is faster in a microbenchmark but has the fundamental problem that it evics the data from the cpu cache; the actual USE of the data thus is a LOT more expensive, result is that the overall system performance goes down ;( --=-dxOrFj0RXcoKEdIGcQec Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQBBIbN2xULwo51rQBIRAqahAJ923/F/630U7c+c/RSfiJma2A8YBwCdG8d5 oOcgTcgaRhP2zqtX/SCYxN0= =hSl7 -----END PGP SIGNATURE----- --=-dxOrFj0RXcoKEdIGcQec--