Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751243AbWIKINd (ORCPT ); Mon, 11 Sep 2006 04:13:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751247AbWIKINc (ORCPT ); Mon, 11 Sep 2006 04:13:32 -0400 Received: from gw.goop.org ([64.81.55.164]:53199 "EHLO mail.goop.org") by vger.kernel.org with ESMTP id S1751243AbWIKINc (ORCPT ); Mon, 11 Sep 2006 04:13:32 -0400 Message-ID: <45051AA5.6090102@goop.org> Date: Mon, 11 Sep 2006 01:13:25 -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: <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> <45051330.5050205@goop.org> <20060911073649.GA3188@elte.hu> <4505176B.6030803@goop.org> <20060911080115.GB5328@elte.hu> In-Reply-To: <20060911080115.GB5328@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: 1059 Lines: 28 Ingo Molnar wrote: > the ratio between the number of syscalls vs. the number of context > switches is 1-2 orders of magnitude. So a loss of 9 cycles in the > syscall path is roughly equal to a loss of 90-900 cycles in switch_to() > costs ... > I agree. > the TLS ABI is just a gcc stupidity. Why did they pick the _second_ > extra selector, instead of the first one ...? Well, it doesn't matter which they chose if its the same for user and kernel space. Why does x86-64 have swapgs rather than swapfs? > Anyway, perhaps this could > be solved by extending gcc with a switch to also generate __thread code > off %fs. Probably not worth the pain though ... If there's gcc hacking to be done, it would be trying to get it make the TLS offsets from the PDA/TCB positive rather than negative... 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/