Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755935AbXFGIrg (ORCPT ); Thu, 7 Jun 2007 04:47:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752199AbXFGIrU (ORCPT ); Thu, 7 Jun 2007 04:47:20 -0400 Received: from one.firstfloor.org ([213.235.205.2]:46257 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755639AbXFGIrN (ORCPT ); Thu, 7 Jun 2007 04:47:13 -0400 Date: Thu, 7 Jun 2007 10:47:11 +0200 From: Andi Kleen To: Yinghai Lu Cc: "Eric W. Biederman" , Alan Cox , Justin Piszcz , Jesse Barnes , Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: Intel's response Linux/MTRR/8GB Memory Support / Why doesn't the kernel realize the BIOS has problems and re-map appropriately? Message-ID: <20070607084711.GB15226@one.firstfloor.org> References: <200706011407.51779.jbarnes@virtuousgeek.org> <20070601211943.GO7217@one.firstfloor.org> <200706011441.57149.jbarnes@virtuousgeek.org> <20070604201823.7b7cb328@the-village.bc.nu> <86802c440706041759q1b2d528ex24b3de514d09d9ef@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <86802c440706041759q1b2d528ex24b3de514d09d9ef@mail.gmail.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1014 Lines: 26 On Mon, Jun 04, 2007 at 05:59:59PM -0700, Yinghai Lu wrote: > On 6/4/07, Eric W. Biederman wrote: > > > >Exactly, and given that this is a fairly easy thing to do, and that > >occasionally we see systems where this happens (even if their BIOS is > >later fixed). It is likely worth it for someone to write up the patch > >and that compare MTRRs with available memory, and to complain and > >reserve all memory that MTRRs claim is not write-back. > > > that is good. > Sometime BIOS can not even keep mtrr to the identical between > different CPU in SMP system. The MTRR code already fixes this case. Or at least mostly -- it doesn't do it for fixed size MTRRs. > Or reset mtrr according to e820 table. That would be likely dangerous. -Andi - 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/