From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764988AbXKUAKz (ORCPT ); Tue, 20 Nov 2007 19:10:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758628AbXKUAKq (ORCPT ); Tue, 20 Nov 2007 19:10:46 -0500 Received: from relay1.sgi.com ([192.48.171.29]:49296 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755453AbXKUAKq (ORCPT ); Tue, 20 Nov 2007 19:10:46 -0500 Date: Tue, 20 Nov 2007 16:10:45 -0800 (PST) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Andi Kleen cc: akpm@linux-foundation.org, travis@sgi.com, Mathieu Desnoyers , linux-kernel@vger.kernel.org Subject: Re: [rfc 08/45] cpu alloc: x86 support In-Reply-To: Message-ID: References: <20071120011132.143632442@sgi.com> <200711201301.25373.ak@suse.de> <200711202159.36377.ak@suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 20 Nov 2007, Christoph Lameter wrote: > 32bit sign extension for what? Absolute data references? The addressing > that I have seen was IP relative. Thus I thought that the kernel could be > moved lower. Argh. This is all depending on a special gcc option to compile the kernel and that option limits the kernel to the upper 2GB. So I guess for CPU_PTR we need to explicitly load the address as a constant, use that as a base and then add the offset and the smp_id shifted to it in the instruction. The CPU_INC/DEC stuff using gs is not affected.