Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761787AbXF0RHU (ORCPT ); Wed, 27 Jun 2007 13:07:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754801AbXF0RHG (ORCPT ); Wed, 27 Jun 2007 13:07:06 -0400 Received: from mga03.intel.com ([143.182.124.21]:57118 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754508AbXF0RHF (ORCPT ); Wed, 27 Jun 2007 13:07:05 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.16,467,1175497200"; d="scan'208";a="244017144" From: Jesse Barnes To: Pim Zandbergen Subject: Re: [PATCH] trim memory not covered by WB MTRRs Date: Wed, 27 Jun 2007 10:06:16 -0700 User-Agent: KMail/1.9.7 Cc: Mauro Giachero , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Andi Kleen , Justin Piszcz , "Eric W. Biederman" , Yinghai Lu References: <200706251434.43863.jesse.barnes@intel.com> <200706270922.05801.jesse.barnes@intel.com> <4682982B.8060200@macroscoop.nl> In-Reply-To: <4682982B.8060200@macroscoop.nl> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200706271006.16956.jesse.barnes@intel.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1737 Lines: 44 On Wednesday, June 27, 2007 10:02:35 Pim Zandbergen wrote: > Jesse Barnes wrote: > > It looks like end_pfn might be ~0UL now... can you print that out > > in your configuration? > > Er, do you need the value of end_pfn ? > Here's what I changed: > > if ((highest_addr >> PAGE_SHIFT) != end_pfn) { > printk(KERN_WARNING "***************\n"); > printk(KERN_WARNING "**** WARNING: likely BIOS bug\n"); > printk(KERN_WARNING "**** MTRRs don't cover all of " > "memory, trimmed %lu pages\n", end_pfn - > (highest_addr >> PAGE_SHIFT)); > printk(KERN_WARNING "**** end_pfn before = %lu\n", end_pfn); > end_pfn = highest_addr >> PAGE_SHIFT; > printk(KERN_WARNING "**** end_pfn after = %lu\n", end_pfn); > printk(KERN_WARNING "***************\n"); > } > > Here's the result: > *************** > **** WARNING: likely BIOS bug > **** MTRRs don't cover all of memory, trimmed 18446744073709486080 > pages **** end_pfn before = 2293760 > **** end_pfn after = 2359296 > *************** > > Hope that's what you needed. Yeah, that's what I needed. end_pfn looks ok, but I guess my test is a little too precise. It should be if ((highest_addr >> PAGE_SHIFT) < end_pfn) rather than !=. That should keep it from trying to extend your memory with bogus math. I thought that the two values should always match, but I guess slightly different memory configurations might break that assumption. Thanks, Jesse - 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/