Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967133AbXFHB63 (ORCPT ); Thu, 7 Jun 2007 21:58:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1764777AbXFHB6W (ORCPT ); Thu, 7 Jun 2007 21:58:22 -0400 Received: from shawidc-mo1.cg.shawcable.net ([24.71.223.10]:45036 "EHLO pd3mo2so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751427AbXFHB6V (ORCPT ); Thu, 7 Jun 2007 21:58:21 -0400 Date: Thu, 07 Jun 2007 19:57:26 -0600 From: Robert Hancock Subject: Re: [PATCH] trim memory not covered by WB MTRRs In-reply-to: To: Justin Piszcz Cc: Jesse Barnes , Randy Dunlap , Andi Kleen , linux-kernel@vger.kernel.org, "Eric W. Biederman" Message-id: <4668B786.7030900@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit References: User-Agent: Thunderbird 2.0.0.0 (Windows/20070326) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1512 Lines: 41 Justin Piszcz wrote: >> Note that your boot also mentions this: >> >> [ 106.449661] mtrr: no more MTRRs available >> >> which indicates that things like X may not be able to map the >> framebuffer with the 'write-combine' attribute, which will hurt >> performance. I've heard reports that turning of 'Intel QST fan >> control' in your BIOS settings will prevent all your MTRRs from being >> used (improperly, probably another BIOS bug) so that X will perform >> well. But if you don't use X on this machine, you don't have to worry >> about it. The other option would be to remap your MTRRs by hand to >> free one up for X, you can do that by combining the last one or two >> entries into a single MTRR using the API described in >> Documentation/mtrr.txt before you start X. >> >> Jesse >> > > FYI-- > > [ 106.449661] mtrr: no more MTRRs available > > This has always occurred, even with mem=8832M setting. > > Justin. Yes, it's another consequence of the way your BIOS configured the MTRRs (wastefully, using more of the precious register entries than it needed to, in addition to not covering all of the RAM). -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/ - 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/