Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756859AbYGJQWY (ORCPT ); Thu, 10 Jul 2008 12:22:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751251AbYGJQWO (ORCPT ); Thu, 10 Jul 2008 12:22:14 -0400 Received: from relay1.sgi.com ([192.48.171.29]:47975 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751514AbYGJQWM (ORCPT ); Thu, 10 Jul 2008 12:22:12 -0400 Message-ID: <48763732.7020805@sgi.com> Date: Thu, 10 Jul 2008 09:22:10 -0700 From: Mike Travis User-Agent: Thunderbird 2.0.0.6 (X11/20070801) MIME-Version: 1.0 To: "Eric W. Biederman" CC: "H. Peter Anvin" , Jeremy Fitzhardinge , Arjan van de Ven , Ingo Molnar , Andrew Morton , Christoph Lameter , Jack Steiner , linux-kernel@vger.kernel.org, Rusty Russell 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> <20080709133958.612635f0@infradead.org> <4875231F.1020506@zytor.com> <487524A0.6020304@goop.org> <487529AE.3060505@zytor.com> <48753A71.2030006@zytor.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 833 Lines: 19 Eric W. Biederman wrote: ... > Another alternative that almost fares better then a segment with > a base of zero is a base of -32K or so. Only trouble that would get us > manually managing the per cpu area size again. One thing to remember is the eventual goal is implementing the cpu_alloc functions which I think we've agreed has to be "growable". This means that the addresses will need to be virtual to allow the same offsets for all cpus. The patchset I have uses 2Mb pages. This "little" twist might figure into the implementation issues that are being discussed. Thanks, Mike -- 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/