Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934538Ab0GOT2W (ORCPT ); Thu, 15 Jul 2010 15:28:22 -0400 Received: from claw.goop.org ([74.207.240.146]:42631 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934378Ab0GOT2V (ORCPT ); Thu, 15 Jul 2010 15:28:21 -0400 Message-ID: <4C3F6153.6020005@goop.org> Date: Thu, 15 Jul 2010 12:28:19 -0700 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.10) Gecko/20100621 Fedora/3.0.5-1.fc13 Lightning/1.0b2pre Thunderbird/3.0.5 MIME-Version: 1.0 To: "H. Peter Anvin" CC: Zachary Amsden , Glauber Costa , Thomas Gleixner , Avi Kivity , Linux Kernel Mailing List Subject: Re: [PATCH] x86: fix ordering constraints on crX read/writes References: <4C3E363B.7060804@goop.org> <4C3E5637.4010300@redhat.com> <4C3E5C8C.8000800@goop.org> <4C3F1C84.8080503@goop.org> <4C3F5972.2030600@zytor.com> In-Reply-To: <4C3F5972.2030600@zytor.com> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 606 Lines: 15 On 07/15/2010 11:54 AM, H. Peter Anvin wrote: > No, we haven't. You're misunderstanding what a "memory" clobber does. > A clobber affects the output side only, but doesn't inherently provide > ordering on the input side. Apparently this is implicit in "asm > volatile", which is a very important property. OK. It would be nice to get that confirmed. J -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/