From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932787AbYEHVnL (ORCPT ); Thu, 8 May 2008 17:43:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757098AbYEHVm4 (ORCPT ); Thu, 8 May 2008 17:42:56 -0400 Received: from terminus.zytor.com ([198.137.202.10]:53601 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755336AbYEHVmz (ORCPT ); Thu, 8 May 2008 17:42:55 -0400 Message-ID: <482373C5.1060202@zytor.com> Date: Thu, 08 May 2008 14:42:29 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Venki Pallipadi CC: Rufus & Azrael , Ingo Molnar , "Siddha, Suresh B" , Linux-kernel Mailing List , Yinghai Lu , Thomas Gleixner Subject: Re: [2.6.25-git18 => 2.6.26-rc1-git1] Xorg crash with xf86MapVidMem error References: <4820962B.6050702@numericable.fr> <924EFEDD5F540B4284297C4DC59F3DEE01004FC1@orsmsx423.amr.corp.intel.com> <4820D415.5090900@numericable.fr> <924EFEDD5F540B4284297C4DC59F3DEE010050B6@orsmsx423.amr.corp.intel.com> <482217F3.2040900@numericable.fr> <924EFEDD5F540B4284297C4DC59F3DEE010057B4@orsmsx423.amr.corp.intel.com> <4822A6F7.7010704@numericable.fr> <20080508192555.GA8643@linux-os.sc.intel.com> <48235DA1.5060809@numericable.fr> <20080508213722.GA28372@linux-os.sc.intel.com> In-Reply-To: <20080508213722.GA28372@linux-os.sc.intel.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 Venki Pallipadi wrote: > On Thu, May 08, 2008 at 01:08:01PM -0700, Rufus & Azrael wrote: >> Venki Pallipadi a ecrit : >> > >> > Use UC_MINUS in reserve_memtype call with -1, when MTRR lookup fails for >> any >> > reason. >> > >> > Change the logic in mtrr_type_lookup to just get the type from the start >> > address. Using start and end adddress is not right/complete as start and >> > end can be covered by different mtrr (where old code will fail) or >> > start and end can be in same mtrr, but still have some different >> > memory type region in between. Using only start is less restrictive and >> > deterministic. >> > >> > Signed-off-by: Venkatesh Pallipadi >> > >> > --- >> > arch/x86/kernel/cpu/mtrr/generic.c | 7 ++----- >> > arch/x86/mm/pat.c | 8 +------- >> > 2 files changed, 3 insertions(+), 12 deletions(-) >> > >> >> Hi Venki, >> >> Patch applied on 2.6.26-rc1-git5 and all works fine in X server with >> CONFIG_X86_PAT=y. >> >> See dmesg and mtrr files attached. >> > > Thanks for reporting the problem and testing the fix. > ingo/thomas/hpa: Can you please pick up this patch. Fixes the PAT regression > reported on this thread. Hm... I have *serious* concerns about this; this might paper over this particular problem, but it just isn't *correct*. The fact that the range check is implemented incorrectly is not an excuse to just dump it and ignore the problem; it should be fixed instead. -hpa