Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753344AbYGJAYk (ORCPT ); Wed, 9 Jul 2008 20:24:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752800AbYGJAYb (ORCPT ); Wed, 9 Jul 2008 20:24:31 -0400 Received: from gw.goop.org ([64.81.55.164]:58604 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752310AbYGJAY3 (ORCPT ); Wed, 9 Jul 2008 20:24:29 -0400 Message-ID: <487556A5.5090907@goop.org> Date: Wed, 09 Jul 2008 17:24:05 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: "H. Peter Anvin" CC: "Eric W. Biederman" , Christoph Lameter , Ingo Molnar , Mike Travis , Andrew Morton , Jack Steiner , linux-kernel@vger.kernel.org, Arjan van de Ven Subject: Re: [RFC 00/15] x86_64: Optimize percpu accesses References: <20080709165129.292635000@polaris-admin.engr.sgi.com> <20080709200757.GD14009@elte.hu> <48751B57.8030605@goop.org> <48751CF9.4020901@linux-foundation.org> <4875209D.8010603@goop.org> <48752CCD.30507@linux-foundation.org> <48753C99.5050408@goop.org> <487555A8.2050007@zytor.com> In-Reply-To: <487555A8.2050007@zytor.com> X-Enigmail-Version: 0.95.6 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: 1011 Lines: 32 H. Peter Anvin wrote: > Eric W. Biederman wrote: >> Jeremy Fitzhardinge writes: >> >>>> Which means that my idea of using the technique we use on x86_32 >>>> will not >>> work. >>> >>> No, the compiler memory model we use guarantees that everything will >>> be within >>> 2G of each other. The linker will spew loudly if that's not the case. >> >> The per cpu area is at least theoretically dynamically allocated. >> And we >> really want to put it in cpu local memory. Which means on any >> reasonable >> NUMA machine the per cpu areas should be all over the box. >> >> So there is no guarantee that with an arbitrary 64bit address in %gs >> of anything. >> > > That doesn't matter in the slightest. Creepy, get out of my brain. 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/