From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422704AbXDCUYf (ORCPT ); Tue, 3 Apr 2007 16:24:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422673AbXDCUYf (ORCPT ); Tue, 3 Apr 2007 16:24:35 -0400 Received: from gw.goop.org ([64.81.55.164]:60257 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422695AbXDCUYe (ORCPT ); Tue, 3 Apr 2007 16:24:34 -0400 Message-ID: <4612B7EF.4080100@goop.org> Date: Tue, 03 Apr 2007 13:24:15 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: Andi Kleen CC: Alan Cox , Ulrich Drepper , Linux Kernel , Andrew Morton Subject: Re: getting processor numbers References: <461286D6.2040407@redhat.com> <46128C1B.1090900@redhat.com> <20070403182241.4b9abab6@the-village.bc.nu> <20070403173010.GC23689@one.firstfloor.org> In-Reply-To: <20070403173010.GC23689@one.firstfloor.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andi Kleen wrote: > Migration is fundamentally incompatible with many CPU optimizations. > But that's not a reason to not optimize anymore. > I've been thinking about ways in which Xen could provide the current vcpu->cpu map to guest domains. Obviously this would change over time, but it could remain current enough to be useful. > But I guess luckily most migration users will be able to live > with a little decreased performance after it. > At least in the Xen case, the source and target machines need to be fairly similar in architecture (can't deal with vastly different CPU types, for example). J