Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756727Ab0FHV6S (ORCPT ); Tue, 8 Jun 2010 17:58:18 -0400 Received: from terminus.zytor.com ([198.137.202.10]:55787 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756704Ab0FHV6R (ORCPT ); Tue, 8 Jun 2010 17:58:17 -0400 Message-ID: <4C0EBCE1.2070609@zytor.com> Date: Tue, 08 Jun 2010 14:57:53 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100430 Fedora/3.0.4-3.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: Alan Cox CC: Ondrej Zary , Ingo Molnar , Yuhong Bao , linux-kernel@vger.kernel.org, gregkh@suse.de Subject: Re: Windows side agrees that lowmem corruption is a problem too References: <4C0E949D.6090002@zytor.com> <20100608190848.GD25985@elte.hu> <201006082122.25089.linux@rainbow-software.org> <20100608225656.7f645621@lxorguk.ukuu.org.uk> In-Reply-To: <20100608225656.7f645621@lxorguk.ukuu.org.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1367 Lines: 32 On 06/08/2010 02:56 PM, Alan Cox wrote: >>> 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. > > Losing the low 1MB is bad thing anyway for things like firmware flashing > and other weird crap that needs low pages (floppy controllers etc). > > Losing 64K (but reporting corruption in it in a big scary way) is > probably sensible for distributions, but its a config item so its policy > so that wouldn't be a problem. > > It has to be painful to the vendors so they get complaints, reports and > support call costs. Otherwise they won't have the correct incentives to > fix their mess. We have already functionally lost 64K on all existing machines... I think the current blacklist covers 90% or more of all systems in existence, and we keep filling in the few holes that remain. Adding the remaining half-megabyte of RAM really shouldn't be done unconditionally, but as I said it could plausibly be reserved for ZONE_DMA only. -hpa -- 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/