From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754132AbXDWTKp (ORCPT ); Mon, 23 Apr 2007 15:10:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754142AbXDWTKp (ORCPT ); Mon, 23 Apr 2007 15:10:45 -0400 Received: from gw.goop.org ([64.81.55.164]:36613 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754132AbXDWTKo (ORCPT ); Mon, 23 Apr 2007 15:10:44 -0400 Message-ID: <462D04B2.6080008@goop.org> Date: Mon, 23 Apr 2007 12:10:42 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: "Eric W. Biederman" CC: Jeremy Fitzhardinge , lkml , Chris Wright , virtualization@lists.osdl.org, Chuck Ebbert , "H. Peter Anvin" , Andrew Morton , Linus Torvalds Subject: Re: [PATCH 10/28] i386: map enough initial memory to create lowmem mappings References: <20070414204154.871250608@goop.org> <200704192250.52633.ak@suse.de> <4627D756.5020405@zytor.com> <200704192304.01053.ak@suse.de> <4627DB0C.2010804@zytor.com> <4627DDAD.4070805@redhat.com> <4627E099.209@goop.org> <462CE027.4030302@goop.org> <462CE1E0.9060007@zytor.com> <462CF5B8.4070708@xensource.com> In-Reply-To: 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 Eric W. Biederman wrote: > If (cpu_has_pse) it may only be an additional two pages. > INIT_MAP_BEYOND is currently mapping a lot more then that. > Ah, yes. It allocates an extra two pages for pagetables, and then maps an extra 8MB or so. >> Would that be necessary? Is there any need to remap it? Couldn't you >> just do the straightforward phys->virt mapping and use the page where it >> lies? >> > > Catch-22. If the page is not mapped yet you can't use it where it lies. Why not? Er, except in the case where the page is needed to map itself - but that can be dealt with with a transient fixmap mapping. J