From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753240AbXDEQzv (ORCPT ); Thu, 5 Apr 2007 12:55:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753285AbXDEQzv (ORCPT ); Thu, 5 Apr 2007 12:55:51 -0400 Received: from terminus.zytor.com ([192.83.249.54]:56296 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753240AbXDEQzu (ORCPT ); Thu, 5 Apr 2007 12:55:50 -0400 Message-ID: <46152A04.1010009@zytor.com> Date: Thu, 05 Apr 2007 09:55:32 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: Andreas Herrmann CC: Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86: limit mwait_idle to Intel CPUs References: <20070405140045.GN6356@alberich.amd.com> <200704051624.45747.ak@suse.de> <20070405144442.GP6356@alberich.amd.com> <200704051737.17157.ak@suse.de> <20070405162049.GB14326@alberich.amd.com> In-Reply-To: <20070405162049.GB14326@alberich.amd.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andreas Herrmann wrote: > > It is not equivalent. Usually users check /proc/cpuinfo for their > CPU features. Deleting that flag is kind of obfuscation. > > I guess some time ago people did not care about their "svm" or "vmx" > flags. Nowadays (e.g. with kvm) some people are quite happy > if one of those strings occurs in /proc/cpuinfo (and they are quite > disappointed if this feature was disabled by BIOS). > What you're saying is that you want it to appear in /proc/cpuinfo for marketing reasons even though it's not usable. The ones in /proc/cpuinfo are cooked values anyway; there is plenty of history to that effect. I would agree with Andi that if as far as Linux is concerned mwait is unusable on AMD Fam10 processors, then the CPU detection code should turn this bit off on AMD Fam10 processors. -hpa