Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933689AbWKWN1L (ORCPT ); Thu, 23 Nov 2006 08:27:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933696AbWKWN1L (ORCPT ); Thu, 23 Nov 2006 08:27:11 -0500 Received: from calculon.skynet.ie ([193.1.99.88]:56760 "EHLO calculon.skynet.ie") by vger.kernel.org with ESMTP id S933689AbWKWN1K (ORCPT ); Thu, 23 Nov 2006 08:27:10 -0500 Date: Thu, 23 Nov 2006 13:27:07 +0000 To: ak@suse.de Cc: akpm@osdl.org, bunk@stusta.de, torvalds@osdl.org, rientjes@cs.washington.edu, maan@systemlinux.org, linux-kernel@vger.kernel.org Subject: [PATCH] Fix bug where early_node_map[] is not sorted before use Message-ID: <20061123132707.GA22611@skynet.ie> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline User-Agent: Mutt/1.5.9i From: mel@skynet.ie (Mel Gorman) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2343 Lines: 59 With reference to this bug; > Subject : x86_64: Bad page state in process 'swapper' > References : http://lkml.org/lkml/2006/11/10/135 > http://lkml.org/lkml/2006/11/10/208 > Submitter : Andre Noll > Handled-By : David Rientjes > Status : problem is being debugged The problem was within architecture-independent zone-sizing and exposed by a particular SRAT table on x86_64. find_min_pfn_for_node() and find_min_pfn_with_active_regions() both depend on a sorted early_node_map[] to find the correct values. However, sort_node_map() is being called after find_min_pfn_with_active_regions() in free_area_init_nodes(). In most cases, this is ok, but on an x86_64, the SRAT table caused the E820 ranges to be registered out of order. This gave the wrong values for the min PFN range resulting in some pages not being initialised. This patch sorts the early_node_map in find_min_pfn_for_node(). It is a critical fix for 2.6.19. Signed-off-by: Mel Gorman diff -rup linux-2.6.19-rc6-clean/mm/page_alloc.c linux-2.6.19-rc6-sort_in_find_min/mm/page_alloc.c --- linux-2.6.19-rc6-clean/mm/page_alloc.c 2006-11-15 20:03:40.000000000 -0800 +++ linux-2.6.19-rc6-sort_in_find_min/mm/page_alloc.c 2006-11-23 02:23:57.000000000 -0800 @@ -2612,6 +2612,9 @@ unsigned long __init find_min_pfn_for_no { int i; + /* Regions in the early_node_map can be in any order */ + sort_node_map(); + /* Assuming a sorted map, the first range found has the starting pfn */ for_each_active_range_index_in_nid(i, nid) return early_node_map[i].start_pfn; @@ -2680,9 +2683,6 @@ void __init free_area_init_nodes(unsigne max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); } - /* Regions in the early_node_map can be in any order */ - sort_node_map(); - /* Print out the zone ranges */ printk("Zone PFN ranges:\n"); for (i = 0; i < MAX_NR_ZONES; i++) -- -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab - 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/