From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 25 Jun 2002 14:59:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 25 Jun 2002 14:59:52 -0400 Received: from pimout4-ext.prodigy.net ([207.115.63.103]:761 "EHLO pimout4-int.prodigy.net") by vger.kernel.org with ESMTP id ; Tue, 25 Jun 2002 14:59:51 -0400 Message-ID: <026f01c21c7a$3b3df820$fad88842@ribald.com> From: "Niels Christiansen" To: "Andrew Morton" Cc: "Linux Kernel Mailing List" , References: <3D18A26A.73E6DD07@zip.com.au> Subject: Re: [Lse-tech] Re: efficient copy_to_user and copy_from_user routines in Linux Kernel Date: Tue, 25 Jun 2002 13:58:01 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4807.1700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Indeed, I ordered a P4 for these tests while still at IBM but AMD boxes are not available to Mala, I believe. Before I got sacked, I even bought a P4 to test this and other things at home but I lost interest in the matter so never actually got around to testing. When I did test back in February I created a few test programs and found that the code generated by GCC Version 3.x and the library that came with RedHat 6.2 gave almost as good results as the patches Mala then had available. Maybe it is time to see if the compiler has improved enough to scrap the copy code in the kernel in favor of code as generated by the compiler. Niels ----- Original Message ----- From: "Andrew Morton" To: "Mala Anand" Cc: "Linux Kernel Mailing List" ; Sent: Tuesday, June 25, 2002 12:03 PM Subject: [Lse-tech] Re: efficient copy_to_user and copy_from_user routines in Linux Kernel > Mala Anand wrote: > > > > Here is a 2.5.19 patch that improves the performance of IA32 copy_to_user > > and copy_from_user routines used by : > > > > (1) tcpip protocol stack > > (2) file systems > > > > One question: have you tested on other CPU types? This problem is > very specific to Intel hardware. On AMD, the eight-byte alignement > artifact does not exist at all. It could be that your patch is not > desirable on such CPUs? > > ------------------------------------------------------- > This sf.net email is sponsored by: Jabber Inc. > Don't miss the IM event of the season | Special offer for OSDN members! > JabConf 2002, Aug. 20-22, Keystone, CO http://www.jabberconf.com/osdn