From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 789CA6B003D for ; Thu, 5 Feb 2009 16:05:43 -0500 (EST) Message-ID: <498B54A0.7040005@goop.org> Date: Thu, 05 Feb 2009 13:05:36 -0800 From: Jeremy Fitzhardinge MIME-Version: 1.0 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: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Hugh Dickins Cc: Ingo Molnar , William Lee Irwin III , Linux Kernel Mailing List , Linux Memory Management List List-ID: 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org