From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262974AbTIWSvG (ORCPT ); Tue, 23 Sep 2003 14:51:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262798AbTIWSvF (ORCPT ); Tue, 23 Sep 2003 14:51:05 -0400 Received: from palrel11.hp.com ([156.153.255.246]:16035 "EHLO palrel11.hp.com") by vger.kernel.org with ESMTP id S262234AbTIWSvC (ORCPT ); Tue, 23 Sep 2003 14:51:02 -0400 Date: Tue, 23 Sep 2003 11:51:04 -0700 From: Grant Grundler To: Benjamin LaHaise Cc: "Luck, Tony" , "David S. Miller" , davidm@hpl.hp.com, davidm@napali.hpl.hp.com, peter@chubb.wattle.id.au, ak@suse.de, iod00d@hp.com, peterc@gelato.unsw.edu.au, linux-ns83820@kvack.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: NS83820 2.6.0-test5 driver seems unstable on IA64 Message-ID: <20030923185104.GA8477@cup.hp.com> References: <20030923142925.A16490@kvack.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030923142925.A16490@kvack.org> User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 23, 2003 at 02:29:25PM -0400, Benjamin LaHaise wrote: ... > (yet another hardware issue pushed off on software for no significant gain). Even x86 pays at least a one cycle penalty for every misaligned access. In general, open source code has no excuse for using misaligned fields. It's (mostly) avoidable. TCP/IP headers are the historical exception. One could make the same arguement that a modern NIC should not require 16 byte alignment for DMA. It's a tradeoff one way or the other. Just a matter of perspective. grant