From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752828AbZBEUmU (ORCPT ); Thu, 5 Feb 2009 15:42:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751993AbZBEUmL (ORCPT ); Thu, 5 Feb 2009 15:42:11 -0500 Received: from gw.goop.org ([64.81.55.164]:52676 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751984AbZBEUmJ (ORCPT ); Thu, 5 Feb 2009 15:42:09 -0500 Message-ID: <498B4F1F.5070306@goop.org> Date: Thu, 05 Feb 2009 12:42:07 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Hugh Dickins CC: Ingo Molnar , William Lee Irwin III , Linux Kernel Mailing List , Linux Memory Management List Subject: Re: pud_bad vs pud_bad References: <498B2EBC.60700@goop.org> <20090205184355.GF5661@elte.hu> <498B35F9.601@goop.org> <20090205191017.GF20470@elte.hu> In-Reply-To: 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 Hugh Dickins wrote: > However... I forget how the folding works out. The pgd in the 32-bit > PAE case used to have just the pfn and the present bit set in that > little array of four entries: if pud_bad() ends up getting applied > to that, I guess it will blow up. > Ah, that's a good point. > If so, my preferred answer would actually be to make those 4 entries > look more like real ptes; but you may think I'm being a bit silly. > Hardware doesn't allow it. It will explode (well, trap) if you set anything other than P in the top level. By the by, what are the chances we'll be able to deprecate non-PAE 32-bit? J