Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755773AbYBAR5a (ORCPT ); Fri, 1 Feb 2008 12:57:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751156AbYBAR5Y (ORCPT ); Fri, 1 Feb 2008 12:57:24 -0500 Received: from terminus.zytor.com ([198.137.202.10]:60033 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751121AbYBAR5X (ORCPT ); Fri, 1 Feb 2008 12:57:23 -0500 Message-ID: <47A35D55.8080708@zytor.com> Date: Fri, 01 Feb 2008 09:56:37 -0800 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: dean gaudet CC: Yi Yang , tglx@linutronix.de, mingo@redhat.com, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: Re: [PATCH 2.6.24] x86: add sysfs interface for cpuid module References: <1199441414.19185.9.camel@yangyi-dev.bj.intel.com> <1201043126.3861.5.camel@yangyi-dev.bj.intel.com> <1201562058.12722.9.camel@yangyi-dev.bj.intel.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 Content-Length: 678 Lines: 19 dean gaudet wrote: > why do we need another kernel cpuid reading method when sched_setaffinity > exists and cpuid is available in ring3? Because /dev/cpu/*/cpuid: a) predates sched_setaffinity by quite a few years b) is already widely used c) doesn't have issues with relative priorities (using sched_setaffinity can easily wait forever.) d) can be accessed by unprivileged processes given appropriate device info. -hpa -- 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/