Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752005AbWCIX3F (ORCPT ); Thu, 9 Mar 2006 18:29:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752008AbWCIX3F (ORCPT ); Thu, 9 Mar 2006 18:29:05 -0500 Received: from mx.pathscale.com ([64.160.42.68]:6278 "EHLO mx.pathscale.com") by vger.kernel.org with ESMTP id S1751972AbWCIX3D (ORCPT ); Thu, 9 Mar 2006 18:29:03 -0500 Subject: Re: [PATCH 7 of 20] ipath - misc driver support code From: "Bryan O'Sullivan" To: Roland Dreier Cc: rolandd@cisco.com, gregkh@suse.de, akpm@osdl.org, davem@davemloft.net, linux-kernel@vger.kernel.org, openib-general@openib.org In-Reply-To: References: <2f16f504dd4b98c2ce7c.1141922820@localhost.localdomain> Content-Type: text/plain Organization: PathScale, Inc. Date: Thu, 09 Mar 2006 15:29:02 -0800 Message-Id: <1141946942.10693.36.camel@serpentine.pathscale.com> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 803 Lines: 24 On Thu, 2006-03-09 at 15:13 -0800, Roland Dreier wrote: > This is kind of theoritical, but it seems to me that it would be safer > to write this as > > int ipath_unordered_wc(void) > { > return boot_cpu_data.x86_vendor != X86_VENDOR_AMD; > } > > after all, Via is probably going to have an x86-64 CPU one of these > days, and I doubt you've checked that their WC flush is ordered. It's purely a performance optimisation. Since we tune very closely to each CPU, there's no point right now in sort-of-tuning for a CPU that doesn't yet exist :-)