From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751864Ab1JKXou (ORCPT ); Tue, 11 Oct 2011 19:44:50 -0400 Received: from terminus.zytor.com ([198.137.202.10]:56628 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750874Ab1JKXot (ORCPT ); Tue, 11 Oct 2011 19:44:49 -0400 Message-ID: <4E94D4E7.5010001@zytor.com> Date: Tue, 11 Oct 2011 16:44:39 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0) Gecko/20110927 Thunderbird/7.0 MIME-Version: 1.0 To: Jacob Shin CC: Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, x86@kernel.org, Yinghai Lu Subject: Re: [PATCH 1/1] x86, e820: Remove direct mapping of reserved space for HT hole around 1TB References: <1318370975-10817-1-git-send-email-jacob.shin@amd.com> In-Reply-To: <1318370975-10817-1-git-send-email-jacob.shin@amd.com> 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 On 10/11/2011 03:09 PM, Jacob Shin wrote: > The entire HT hole and also the unused address range before that hole > need to be excluded from direct mapping. Otherwise speculative > accesses to that reserved region can happen which cause machine > checks. BARF! This is completely insane ad hockery when all that really should need to happen is marking the HT region RESERVED, which should be possible on any HT-equipped processor. -hpa