Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756798AbZFZDVb (ORCPT ); Thu, 25 Jun 2009 23:21:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753284AbZFZDVZ (ORCPT ); Thu, 25 Jun 2009 23:21:25 -0400 Received: from rex.securecomputing.com ([203.24.151.4]:58177 "EHLO cyberguard.com.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752443AbZFZDVY (ORCPT ); Thu, 25 Jun 2009 23:21:24 -0400 Message-ID: <4A443EB5.40300@snapgear.com> Date: Fri, 26 Jun 2009 13:21:25 +1000 From: Greg Ungerer User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: uClinux development list CC: Linux Kernel Mailing List Subject: Re: [uClinux-dev] Coldfire 5271 hitting BUG_ON(page_count(buddy) != 0); References: <20090625154343.GA10189@csclub.uwaterloo.ca> In-Reply-To: <20090625154343.GA10189@csclub.uwaterloo.ca> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1909 Lines: 53 Hi Lennart, Lennart Sorensen wrote: > I am hitting a memory management bug and I would love some hints as to > how to track down the bug and fix it. > > The bug hit is line 423 of page_alloc.c which is: > > BUG_ON(page_count(buddy) != 0); > > The function it is part of is: > > static inline int page_is_buddy(struct page *page, struct page *buddy, > int order) > { > if (!pfn_valid_within(page_to_pfn(buddy))) > return 0; > > if (page_zone_id(page) != page_zone_id(buddy)) > return 0; > > if (PageBuddy(buddy) && page_order(buddy) == order) { > BUG_ON(page_count(buddy) != 0); > return 1; > } > return 0; > } > > I am seeing this both with 2.6.29.1 and 2.6.30 so far. I unfortunately > haven't poked much at the memory management code, so I am not even sure > what this is supposed to be doing. The cpu us a coldfire 5271. > > I also see crashes causing the kernel to dump lots of hex values. > Building the kernel with debug enabled unfortunately seems to move things > around enough to make it just lock up instead without any output. What are you doing at the time you get this? Or is it at bootup? Regards Greg ------------------------------------------------------------------------ Greg Ungerer -- Principal Engineer EMAIL: gerg@snapgear.com SnapGear Group, McAfee PHONE: +61 7 3435 2888 825 Stanley St, FAX: +61 7 3891 3630 Woolloongabba, QLD, 4102, Australia WEB: http://www.SnapGear.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/