Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753843AbXIPRxg (ORCPT ); Sun, 16 Sep 2007 13:53:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752501AbXIPRx3 (ORCPT ); Sun, 16 Sep 2007 13:53:29 -0400 Received: from wa-out-1112.google.com ([209.85.146.183]:22090 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752489AbXIPRx2 (ORCPT ); Sun, 16 Sep 2007 13:53:28 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=WP8S5Zem85yqCASWNRIBO35xUPBOz43VjHczeFKRhLN2FpEM9gjG8mjJZySyXdTPXpKbaOtPiVVweYg0LiapW9+796Yg6xMKNKwhENDAQplpiC+7LWPv6Rfft1jeNtK2AhIOpeEQXYbe1CL7qZZVGhGgySY/3ktHXe/RQjtVv5I= Message-ID: <86802c440709161053x7f549e84u815c6494d921d393@mail.gmail.com> Date: Sun, 16 Sep 2007 10:53:28 -0700 From: "Yinghai Lu" To: "Howard Chu" , "Andi Kleen" , "Eric W. Biederman" Subject: Re: MTRR initialization Cc: linux-kernel In-Reply-To: <46ED54EF.3040209@symas.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <46EAB7DA.10507@symas.com> <86802c440709141012w1e85e4caue0d2c7f849dba1cb@mail.gmail.com> <46ED54EF.3040209@symas.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1682 Lines: 35 On 9/16/07, Howard Chu wrote: > Yinghai Lu wrote: > > On 9/14/07, Howard Chu wrote: > >> Hi, was wondering if anyone else has been tripped up by this... I've got 4GB of > >> RAM in my Asus A8V Deluxe and memory hole mapping enabled in the BIOS. By > >> default, my system boots up with these MTRR settings: > >> > >> reg00: base=0x00000000 ( 0MB), size=4096MB: write-back, count=1 > >> reg01: base=0x100000000 (4096MB), size=1024MB: write-back, count=1 > >> reg02: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1 > >> reg03: base=0xc0000000 (3072MB), size= 256MB: write-combining, count=1 if rev F before cpu aka Rev E is installed, and 8G RAM installed, it will be > >> reg00: base=0x00000000 ( 0MB), size=8192MB: write-back, count=1 > >> reg01: base=0x100000000 (8192MB), size=1024MB: write-back, count=1 > >> reg02: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1 > >> reg03: base=0xc0000000 (3072MB), size= 256MB: write-combining, count=1 and you will have problem... So good way is get the ram top, and hole size...and reset the whole set ot var mtrr. you could refer the code in LinuxBIOS about setting that... http://www.openbios.org/viewvc/trunk/LinuxBIOSv2/src/cpu/x86/mtrr/mtrr.c?revision=2616&view=markup esp the part about CONFIG_VAR_MTRR_HOLE... but Andi and Eric said resetting mtrr is not good... when someone from intel try to trim the MTRR for intel CPU. YH - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/