From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756063Ab0FHTWr (ORCPT ); Tue, 8 Jun 2010 15:22:47 -0400 Received: from mail1-out1.atlantis.sk ([80.94.52.55]:40357 "EHLO mail.atlantis.sk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755145Ab0FHTWq (ORCPT ); Tue, 8 Jun 2010 15:22:46 -0400 From: Ondrej Zary To: Ingo Molnar Subject: Re: Windows side agrees that lowmem corruption is a problem too Date: Tue, 8 Jun 2010 21:22:20 +0200 User-Agent: KMail/1.9.10 Cc: "H. Peter Anvin" , Yuhong Bao , linux-kernel@vger.kernel.org, gregkh@suse.de References: <4C0E949D.6090002@zytor.com> <20100608190848.GD25985@elte.hu> In-Reply-To: <20100608190848.GD25985@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <201006082122.25089.linux@rainbow-software.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 08 June 2010 21:08:48 Ingo Molnar wrote: > * H. Peter Anvin wrote: > > On 06/08/2010 11:28 AM, Yuhong Bao wrote: > > > Adding mingo and gregkh to CC list. > > > > > >> Remember the lowmem corruption problems that lead the code that > > >> displays this to be added to Linux:> AMI BIOS detected: BIOS may > > >> corrupt low RAM, working around it.> which was IMO way too broad. Good > > >> news, the Windows side agree that this is a problem too:> > > >> http://www.microsoft.com/whdc/system/platform/firmware/mem-corrupt.msp > > >>x>> Yuhong Bao > > > > Hardly "way too broad". I'm starting to think we should enable it > > unconditionally, given the number of machines which have exhibited that > > problem. As shown in the whitepaper, Vista/Win7 even avoid using > > < 1 MB for a lot of things, presumably for this reason. > > > > If it only was suspend, it would be one thing, but from what I've seen > > it has been known to happen at other times too (e.g. HDMI cable > > insertion!) > > Yep, patterns of some silly OSD bitmap showed up in one of the corruption - > firmware displaying a 'you inserted a cable' kind of icon somewhere and > messing up the SMM code or so ... > > I agree that dis-using <1M by default is probably the sanest option. But please limit it to newer systems only (DMI present && year > 200?). There are many old machines running fine. Losing 1MB from 16MB is a bad thing. -- Ondrej Zary