From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937383AbYEBXNz (ORCPT ); Fri, 2 May 2008 19:13:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932513AbYEBXNq (ORCPT ); Fri, 2 May 2008 19:13:46 -0400 Received: from one.firstfloor.org ([213.235.205.2]:43444 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935042AbYEBXNq (ORCPT ); Fri, 2 May 2008 19:13:46 -0400 Message-ID: <481BA025.8020804@firstfloor.org> Date: Sat, 03 May 2008 01:13:41 +0200 From: Andi Kleen User-Agent: Thunderbird 1.5.0.12 (X11/20060911) MIME-Version: 1.0 To: "Moore, Eric" CC: linux-kernel@vger.kernel.org Subject: Re: HELP: Is writeq an atomic operation?? References: <0631C836DBF79F42B5A60C8C8D4E822901047B42@NAMAIL2.ad.lsil.com> In-Reply-To: <0631C836DBF79F42B5A60C8C8D4E822901047B42@NAMAIL2.ad.lsil.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Moore, Eric wrote: > On Friday, May 02, 2008 4:50 PM, Andi Kleen wrote: >>> Here is a trace from pci express analyzer. I'm sending >> With what CPU/chipset was that? >> > > I'm developing sas driver for next generation controllers. They should > work at least on x86, x86_64, ia64, and ppc64. The host I was using for > gathering that trace was x86_64 Intel Platform. Here is the lspci > output: I doubt the CPU was to blame. Probably the chipset split it up for some reason. Did you check the data sheets? At the CPU level writeq is simply a 64bit store on x86-64 Linux. -Andi