From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 3E8716B003D for ; Thu, 5 Feb 2009 16:51:00 -0500 (EST) Date: Thu, 5 Feb 2009 22:50:50 +0100 From: Ingo Molnar Subject: Re: pud_bad vs pud_bad Message-ID: <20090205215050.GB28097@elte.hu> References: <498B2EBC.60700@goop.org> <20090205184355.GF5661@elte.hu> <498B35F9.601@goop.org> <20090205191017.GF20470@elte.hu> <498B4F1F.5070306@goop.org> <498B54A0.7040005@goop.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <498B54A0.7040005@goop.org> Sender: owner-linux-mm@kvack.org To: Jeremy Fitzhardinge Cc: Hugh Dickins , William Lee Irwin III , Linux Kernel Mailing List , Linux Memory Management List List-ID: * Jeremy Fitzhardinge wrote: >> 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). We'd also lose a fair bit of performance (not to mention the pagetable footprint doubling that Hugh already mentioned) on 32-bit PAE capable systems that dont actually have RAM above 4G physical. Bad idea really ... Ingo -- 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