Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753518Ab1FTHpS (ORCPT ); Mon, 20 Jun 2011 03:45:18 -0400 Received: from s15228384.onlinehome-server.info ([87.106.30.177]:54823 "EHLO mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753395Ab1FTHpO (ORCPT ); Mon, 20 Jun 2011 03:45:14 -0400 Date: Mon, 20 Jun 2011 09:44:52 +0200 From: Borislav Petkov To: Hidetoshi Seto Cc: "linux-kernel@vger.kernel.org" , "x86@kernel.org" , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , "Luck, Tony" Subject: Re: [PATCH 2/8] x86, mce: remove redundant mce_available() checks Message-ID: <20110620074451.GD9070@aftab> References: <4DFB1242.90404@jp.fujitsu.com> <4DFB1359.9000204@jp.fujitsu.com> <20110617143947.GH18054@aftab> <4DFED0FD.6060701@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4DFED0FD.6060701@jp.fujitsu.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1460 Lines: 37 On Mon, Jun 20, 2011 at 12:47:57AM -0400, Hidetoshi Seto wrote: > > I don't think this will ever happen so why complicate the code > > needlessly? This can only be executed if at least one of the cores on > > the system has CPUID(1)_EDX, bits 7 and 14 cleared and that's just > > silly. > > This is a guard against such silly situation, isn't it? > I don't think it looks so complicated and needless. > > I think this code will not run on systems with single socket as > long as the processor vendors are in the right mind. > But in cases when it is numa with strange nodes or when it is > migrated to/from misconfigured virtual machine I can't say that > with certainty. Let me put it this way: are you talking about a concrete example where there's machine with the BSP's MCA features enabled and the rest of the cores are not or is this some theoretical thing you're conjecturing? If it is the first I'd really like to know about it, if it's the second, then my initial point stands - no need to handle purely theoretical cases. -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach GM: Alberto Bozzo Reg: Dornach, Landkreis Muenchen HRB Nr. 43632 WEEE Registernr: 129 19551 -- 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/