From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755684AbZANDK3 (ORCPT ); Tue, 13 Jan 2009 22:10:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751667AbZANDKV (ORCPT ); Tue, 13 Jan 2009 22:10:21 -0500 Received: from fk-out-0910.google.com ([209.85.128.191]:60711 "EHLO fk-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751604AbZANDKU (ORCPT ); Tue, 13 Jan 2009 22:10:20 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=Pot5YPVGJIPCO6t/yK7wF5fSGCRcL+mOlNtuNJ0cjc6nIwZwDbXPzO2E4DbiXsiGd2 iO0+DXJRQtZfsBGJoDROKXCpvbwMDWL/vrh4F0nbqHYxHPnWKQERj/u/+0MLC8cHO5X+ uKiEGF4i3ke1i+tBhgwzQie+zSIJInaQJmMeY= Message-ID: Date: Tue, 13 Jan 2009 22:10:18 -0500 From: "James Kirin" To: "Roland Dreier" Subject: Re: memory beyond4GB invisible to the system even though CONFIG_HIGHMEM64G=y Cc: linux-kernel@vger.kernel.org In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thank you for your reply, Roland. Unfortunately, this continues happening after having installed the most recent version of the BIOS available from Dell. I understand this is a problem in the BIOS and not the kernel, but is there a way to have the kernel work around this bug in the BIOS and make that memory accessible? Eg, http://www.gossamer-threads.com/lists/linux/kernel/991748#991748 The difference seems to be that the BIOS on this machine I am using does list 8GB memory available. Thanks for any help, James On Tue, Jan 13, 2009 at 9:22 PM, Roland Dreier wrote: > > I am running kernel 2.6.28 on a computer with 8GB RAM. The BIOS > > detects all 8GB, yet > > > > jk@as12:~$ free > > total used free shared buffers cached > > Mem: 3622504 799696 2822808 0 90936 369604 > > -/+ buffers/cache: 339156 3283348 > > Swap: 6867776 0 6867776 > > The message in your kernel log: > > [ 0.000000] WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing 4096MB of RAM. > [ 0.000000] ------------[ cut here ]------------ > [ 0.000000] WARNING: at arch/x86/kernel/cpu/mtrr/main.c:1662 mtrr_trim_uncached_memory+0x283/0x2a4() > > is a clue. You might want to look for a BIOS update for your > motherboard. > > - R. >