From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932166Ab0CaWfz (ORCPT ); Wed, 31 Mar 2010 18:35:55 -0400 Received: from claw.goop.org ([74.207.240.146]:43364 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755817Ab0CaWfy (ORCPT ); Wed, 31 Mar 2010 18:35:54 -0400 Message-ID: <4BB3CE46.1050105@goop.org> Date: Wed, 31 Mar 2010 15:35:50 -0700 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100301 Fedora/3.0.3-1.fc12 Lightning/1.0b2pre Thunderbird/3.0.3 MIME-Version: 1.0 To: Colin King CC: Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86: Disable 4MB page tables for Atom, work around errata AAE44 References: <1269271251-19775-1-git-send-email-colin.king@canonical.com> In-Reply-To: <1269271251-19775-1-git-send-email-colin.king@canonical.com> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/22/2010 08:20 AM, Colin King wrote: > "If software clears the PS (page size) bit in a present PDE (page directory > entry), that will cause linear addresses mapped through this PDE to use > 4-KByte pages instead of using a large page after old TLB entries are > invalidated. Due to this erratum, if a code fetch uses this PDE before the > TLB entry for the large page is invalidated then it may fetch from a different > physical address than specified by either the old large page translation or > the new 4-KByte page translation. This erratum may also cause speculative code > fetches from incorrect addresses." > Does this only affect non-PAE 32-bit? Or does it also affect 3 and 4 level pagetables with 2MB large pages? J