Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751123AbWIKHln (ORCPT ); Mon, 11 Sep 2006 03:41:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751165AbWIKHln (ORCPT ); Mon, 11 Sep 2006 03:41:43 -0400 Received: from gw.goop.org ([64.81.55.164]:40603 "EHLO mail.goop.org") by vger.kernel.org with ESMTP id S1751123AbWIKHln (ORCPT ); Mon, 11 Sep 2006 03:41:43 -0400 Message-ID: <45051330.5050205@goop.org> Date: Mon, 11 Sep 2006 00:41:36 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.5 (X11/20060907) MIME-Version: 1.0 To: Ingo Molnar CC: Andrew Morton , Andi Kleen , Laurent Riffard , Arjan van de Ven , Kernel development list , Jeremy Fitzhardinge Subject: Re: 2.6.18-rc6-mm1: GPF loop on early boot References: <20060908011317.6cb0495a.akpm@osdl.org> <200609101032.17429.ak@suse.de> <20060910115722.GA15356@elte.hu> <200609101334.34867.ak@suse.de> <20060910132614.GA29423@elte.hu> <20060910093307.a011b16f.akpm@osdl.org> <450499D3.5010903@goop.org> <20060911051028.GA10084@elte.hu> <450510E0.8080906@goop.org> <20060911072959.GA2322@elte.hu> In-Reply-To: <20060911072959.GA2322@elte.hu> 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 Content-Length: 760 Lines: 17 Ingo Molnar wrote: > because userspace does not use it normally, while with %gs we'd switch > between glibc's descriptor [which must be shadowed by the CPU] and the > kernel's descriptor [which must be shadowed by the CPU too] - hence > causing a constant reloading of the shadow register. > Well, that means the only operation which would be different would be the pop %fs at the end, since only it would end up loading a null selector. All the other operations would presumably take just as long. J - 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/