From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: wireless vs. alignment requirements Date: Thu, 29 Nov 2007 09:50:35 -0800 Message-ID: <474EFBEB.5000804@zytor.com> References: <1195893216.4149.186.camel@johannes.berg> <20071124133200.GA27531@gondor.apana.org.au> <1195912176.4149.194.camel@johannes.berg> <20071124141319.GA27819@gondor.apana.org.au> <4748855C.5090103@linux-foundation.org> <474C50D7.5010901@zytor.com> <20071129131107.GC8487@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Stephen Hemminger , Johannes Berg , dsd@gentoo.org, davem@davemloft.net, netdev@vger.kernel.org, linux-wireless@vger.kernel.org To: Herbert Xu Return-path: Received: from terminus.zytor.com ([198.137.202.10]:33574 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763229AbXK2Rvh (ORCPT ); Thu, 29 Nov 2007 12:51:37 -0500 In-Reply-To: <20071129131107.GC8487@gondor.apana.org.au> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Herbert Xu wrote: > On Tue, Nov 27, 2007 at 09:16:07AM -0800, H. Peter Anvin wrote: >> I wrote a patch for the IP stack to realign packets if necessary at one >> point. I should dredge it up again and submit it for collective flamage. > > As long as it doesn't penalise Ethernet (e.g., the 10Gb crowd :) it would > be good to have. > > Thanks, Uhm, most cards affected *ARE* Ethernet cards, due to the bloody 14-byte header. But it doesn't affect architectures which have alignment, and the cost of scanning a properly-aligned packet is minimal. I'll try to find it some time today. -hpa