From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752340Ab1HYHaL (ORCPT ); Thu, 25 Aug 2011 03:30:11 -0400 Received: from ch-smtp04.sth.basefarm.net ([80.76.153.5]:37033 "EHLO ch-smtp04.sth.basefarm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750903Ab1HYHaI (ORCPT ); Thu, 25 Aug 2011 03:30:08 -0400 X-Mailer: exmh version 2.7.2 04/02/2003 (gentoo 2.7.2) with nmh-1.3-dev To: torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, aeriksson@fastmail.fm Subject: mtrr failure, 3.1-rc1 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 25 Aug 2011 09:03:35 +0200 From: Anders Eriksson Message-Id: <20110825070335.3095B3BC183@tippex.mynet.homeunix.org> X-Originating-IP: 83.252.233.92 X-Scan-Result: No virus found in message 1QwUNs-0003sk-Fs. X-Scan-Signature: ch-smtp04.sth.basefarm.net 1QwUNs-0003sk-Fs 450afc85a2f2c0986adcc1b9e50e109f Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org My old P-II has 640MB ram, but the bios only sets up WC for the first 512, so i add this early in the boot process: echo "base=0x20000000 size=0x8000000 type=write-back" > /proc/mtrr For reasons I have forgot I also have to add 'disable_mtrr_check' to the command line. Works great. As of merge dc43d9fa73d82083656fb9c02f4823bcdcfb9f91 This no longer works. Adding that line to /proc/mtrr no longer has any effect (cat /proc/mtrr shows only the reg00 entry). Reverting that merge on top of rc3 brings things back to normal and /proc/mtrr shows: reg00: base=0x000000000 ( 0MB), size= 512MB, count=1: write-back reg01: base=0x048000000 ( 1152MB), size= 128MB, count=1: write-combining reg02: base=0x020000000 ( 512MB), size= 128MB, count=2: write-back Any ideas how to track this down futher? Would be good to get it fixed for 3.1 -Anders