From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758100AbZEHHjT (ORCPT ); Fri, 8 May 2009 03:39:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753769AbZEHHjF (ORCPT ); Fri, 8 May 2009 03:39:05 -0400 Received: from hera.kernel.org ([140.211.167.34]:46668 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754032AbZEHHjC (ORCPT ); Fri, 8 May 2009 03:39:02 -0400 Message-ID: <4A03E13E.6050107@kernel.org> Date: Fri, 08 May 2009 00:37:34 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Ingo Molnar , Mel Gorman , Thomas Gleixner , "H. Peter Anvin" , Andrew Morton CC: "linux-kernel@vger.kernel.org" Subject: [PATCH 2/2] x86: Allow 1MB of slack between the e820 map and SRAT, not 4GB References: <4A01C08F.8020607@kernel.org> <20090507134723.GA32409@csn.ul.ie> <20090507142121.GL481@elte.hu> <4A03E10C.60906@kernel.org> In-Reply-To: <4A03E10C.60906@kernel.org> 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 It is expected that there be slight differences between the e820 map and the SRAT table and the intention was that 1MB of slack be allowed. The calculation comparing e820ram and pxmram assumes the units are bytes, when they are in fact pages. This means 4GB of slack is being allowed, not 1MB. This patch makes the correct comparison comment is from Mel. [ Impact: don't accept the srat that could dump 2g etc ram ] Signed-off-by: Yinghai Lu Acked-by: Mel Gorman --- arch/x86/mm/srat_64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Index: linux-2.6/arch/x86/mm/srat_64.c =================================================================== --- linux-2.6.orig/arch/x86/mm/srat_64.c +++ linux-2.6/arch/x86/mm/srat_64.c @@ -346,8 +346,8 @@ static int __init nodes_cover_memory(con } e820ram = max_pfn - (e820_hole_size(0, max_pfn<>PAGE_SHIFT); - /* We seem to lose 3 pages somewhere. Allow a bit of slack. */ - if ((long)(e820ram - pxmram) >= 1*1024*1024) { + /* We seem to lose 3 pages somewhere. Allow 1M of slack. */ + if ((long)(e820ram - pxmram) >= (1<<(20 - PAGE_SHIFT))) { printk(KERN_ERR "SRAT: PXMs only cover %luMB of your %luMB e820 RAM. Not used.\n", (pxmram << PAGE_SHIFT) >> 20,