From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753827AbZBEVFu (ORCPT ); Thu, 5 Feb 2009 16:05:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752523AbZBEVFm (ORCPT ); Thu, 5 Feb 2009 16:05:42 -0500 Received: from gw.goop.org ([64.81.55.164]:51449 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752445AbZBEVFl (ORCPT ); Thu, 5 Feb 2009 16:05:41 -0500 Message-ID: <498B54A0.7040005@goop.org> Date: Thu, 05 Feb 2009 13:05:36 -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> <498B4F1F.5070306@goop.org> 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: >> Hardware doesn't allow it. It will explode (well, trap) if you set anything >> other than P in the top level. >> > > Oh, interesting, I'd never realized that. > There are some later extensions to reuse some of the bits for things like tlb reload policy (I think; I'd have to check to be sure), so they're fairly non-pte-like. >> By the by, what are the chances we'll be able to deprecate non-PAE 32-bit? >> > > I sincerely hope 0! I shed no tears at losing support for NUMAQ, > but why should we be forced to double all the 32-bit ptes? You want > us all to be using NX? Or you just want to cut your test/edit matrix - > that I can well understand! > Yes, that's the gist of it. We could simplify things by having only one pte format and only have to parameterise with 3/4 level pagetables. We'd lose support for non-PAE cpus, including the first Pentium M (which is probably still in fairly wide use, unfortunately). J