From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756990AbYCKGyA (ORCPT ); Tue, 11 Mar 2008 02:54:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751392AbYCKGxx (ORCPT ); Tue, 11 Mar 2008 02:53:53 -0400 Received: from terminus.zytor.com ([198.137.202.10]:42746 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751244AbYCKGxw (ORCPT ); Tue, 11 Mar 2008 02:53:52 -0400 Message-ID: <47D62A0D.3070107@zytor.com> Date: Tue, 11 Mar 2008 07:43:25 +0100 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Hugh Dickins CC: Ingo Molnar , Linus Torvalds , Andrew Morton , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: P6 NOPs again: MPSC? References: <20080304210111.GB31546@elte.hu> <47CDBE09.3060000@zytor.com> <47D59743.7040709@zytor.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hugh Dickins wrote: > > Yup, I realized that (with || in place of &&): I meant that perhaps > it was supposed to say X86_64 || (!X86_GENERIC && (M686 || ....)) > since quite a lot of other options there have "|| X86_64" to cover > all the 64-bit possibilities at once i.e. is it only MPSC that > needs to be added, or both MPSC and CPU_GENERIC? > No. The left-hand clause (X86_64 || !X86_GENERIC) indicates when using these NOPs are *permitted*; the right-hand clause indicates when doing so is *desirable*. The latter isn't, for example, for K8, even on 64 bits. -hpa