From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756546AbYCJU2N (ORCPT ); Mon, 10 Mar 2008 16:28:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751165AbYCJU17 (ORCPT ); Mon, 10 Mar 2008 16:27:59 -0400 Received: from terminus.zytor.com ([198.137.202.10]:54371 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750855AbYCJU16 (ORCPT ); Mon, 10 Mar 2008 16:27:58 -0400 Message-ID: <47D59743.7040709@zytor.com> Date: Mon, 10 Mar 2008 21:17:07 +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> 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: > I've now noticed that the machine I call MPENTIUM4 for 32-bit kernels > is called MPSC for 64-bit kernels, and in that case it still doesn't > get the P6 NOPs which I'm guessing it ought to (yeah, I'm so excited > about the speedup I can expect from P6 NOPs, can we perhaps have a > little silvery "Using Genuine P6 NOPs" sticker to put on the box? ;) > > I'm suspecting that the patch below is actually wrong, and that it's > really the "(X86_64 || !X86_GENERIC) &&" which should be changed; > but very unsure of my ground and what's right for CPU_GENERIC - > the 32/64 heritage of x86/Kconfig.cpu rather confuses me. > > Over to you to do the right thing, I'm hoping, please, Peter! > X86_64 && !X86_GENERIC comes from not wanting to be a compatibility issue when compiling for generic CPUs. There are some 32-bit otherwise i686-compatible chips (from VIA and Transmeta) which don't have these NOPs. -hpa