From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756383AbZBFAIn (ORCPT ); Thu, 5 Feb 2009 19:08:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753432AbZBFAIf (ORCPT ); Thu, 5 Feb 2009 19:08:35 -0500 Received: from gw.goop.org ([64.81.55.164]:47566 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752462AbZBFAIe (ORCPT ); Thu, 5 Feb 2009 19:08:34 -0500 Message-ID: <498B7F7F.3090701@goop.org> Date: Thu, 05 Feb 2009 16:08:31 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Ingo Molnar CC: Hugh Dickins , 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> <498B54A0.7040005@goop.org> <20090205215050.GB28097@elte.hu> <498B6325.1040401@goop.org> <20090205234241.GA14203@elte.hu> In-Reply-To: <20090205234241.GA14203@elte.hu> 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 Ingo Molnar wrote: > just the act of using PAE was measured to cause multi-percent slowdown in > fork() and exec() latencies, etc. The pagetables are twice as large so is > that really surprising? > Is there a similar slowdown running the CPU in 32 vs 64 bit mode? Or does having more/wider registers mitigate it? J