From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 2 Apr 2003 15:50:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 2 Apr 2003 15:50:05 -0500 Received: from chaos.analogic.com ([204.178.40.224]:49814 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id ; Wed, 2 Apr 2003 15:50:04 -0500 Date: Wed, 2 Apr 2003 16:03:02 -0500 (EST) From: "Richard B. Johnson" X-X-Sender: root@chaos Reply-To: root@chaos.analogic.com To: Dennis Cook cc: linux-kernel@vger.kernel.org, kernelnewbies@nl.linux.org Subject: Re: Deactivating TCP checksumming In-Reply-To: Message-ID: References: <20030401122824.GY29167@mea-ext.zmailer.org> <20030402203653.GA2503@gtf.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2 Apr 2003, Dennis Cook wrote: > What I was looking for is a general capability to keep the SW transport > stack from > computing outgoing TCP/UDP/IP checksums so that the HW can be allowed to do > it, > similar to Windows checksum offload capability. REALLY? Who are you kidding. Windows has no such capability. Check \WINDOWS\SYSTEM32\DRIVERS\ETC\* and see who they stole the TCP/IP stack from! Further, when you perform normal user->TCP/IP operations, you get checksumming for free as part of the copy operation. It's only when you don't even copy data that you can get any advantage of not checksumming. That's why sendfile disables it. Cheers, Dick Johnson Penguin : Linux version 2.4.20 on an i686 machine (797.90 BogoMips). Why is the government concerned about the lunatic fringe? Think about it.