From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 3 Aug 2001 11:29:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 3 Aug 2001 11:29:50 -0400 Received: from mg02.austin.ibm.com ([192.35.232.12]:17104 "EHLO mg02.austin.ibm.com") by vger.kernel.org with ESMTP id ; Fri, 3 Aug 2001 11:29:36 -0400 Content-Type: text/plain; charset=US-ASCII From: Andrew Theurer Reply-To: andrewt@austin.rr.com To: linux-kernel@vger.kernel.org Subject: Re: TCP zero-copy Date: Fri, 3 Aug 2001 10:28:53 -0500 X-Mailer: KMail [version 1.2] In-Reply-To: <663CE32D.1D4A9213.0F45C3B8@netscape.net> <3B6A7B96.1591.241743@localhost> In-Reply-To: <3B6A7B96.1591.241743@localhost> MIME-Version: 1.0 Message-Id: <01080310285302.02989@linux> Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 03 August 2001 04:23, wrote: > I believe this behaviour is only possible for cards which have the > ability to dma what appears as a list of skb data fragments and > also has the ability to checksum the data. Namely the Alteon, now > 3com, ACENIC and the sun hme device. Intel now has an e1000 driver as well. > Does this kernel modification completely remove the need for a > copy/checksum of the data between user and kernel space on both > transmit and receive ? Transmit for sure. You should no longer see csum_partial_copy_generic() when using zerocopy. > I have written a driver for an Intel ixf1002 chip, which has some > surrounding HW, and is capable of checksumming and processing > dma in fragments. Is there any information on what changes I > would have to make to the driver to support zerocopy/checksum ? Which card is this? Andrew Theurer