From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753451AbYJUKn0 (ORCPT ); Tue, 21 Oct 2008 06:43:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752584AbYJUKnR (ORCPT ); Tue, 21 Oct 2008 06:43:17 -0400 Received: from e28smtp07.in.ibm.com ([59.145.155.7]:55731 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752571AbYJUKnQ (ORCPT ); Tue, 21 Oct 2008 06:43:16 -0400 Message-ID: <48FDB23D.6080603@linux.vnet.ibm.com> Date: Tue, 21 Oct 2008 16:13:09 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com Organization: IBM User-Agent: Thunderbird 2.0.0.17 (X11/20080925) MIME-Version: 1.0 To: Ingo Molnar CC: KAMEZAWA Hiroyuki , Andrew Morton , linux-kernel@vger.kernel.org, Linus Torvalds , Daisuke Nishimura , Rik van Riel , Hiroshi Shimamoto , lee.schermerhorn@hp.com, lizf@cn.fujitsu.com Subject: Re: [crash, -git] NULL pointer dereference, IP: [] page_cgroup_zoneinfo+0xf/0x1b References: <20081021100935.GA7100@elte.hu> <20081021192143.67361afc.kamezawa.hiroyu@jp.fujitsu.com> <20081021103843.GA18150@elte.hu> In-Reply-To: <20081021103843.GA18150@elte.hu> 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 Ingo Molnar wrote: > * KAMEZAWA Hiroyuki wrote: > >>> BUG: unable to handle kernel NULL pointer dereference at 00000000 >>> IP: [] page_cgroup_zoneinfo+0xf/0x1b > [...] >>> bad: a9b6148: USB: Fix unused label warnings in drivers/usb/host/ehci-hcd.c >>> good: c813b4e: Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/ >>> >> yes, now chasing. and have found >> >> page_cgroup->page is NULL because of unknown reason. > > i've attempted to bisect it - but the most critical part of this series > is not bisectable, the bootup hangs at this tree: > > 40b6a76: cpuset.c: remove extra variable > > It hangs in the mm/cgroups code at: > > [] ? constant_test_bit+0xe/0x1b > [] lock_page_cgroup+0x13/0x25 > [] mem_cgroup_charge_common+0xfd/0x1bf > [] mem_cgroup_cache_charge+0x7c/0x8a > [] add_to_page_cache_locked+0x2f/0xc4 > [] add_to_page_cache_lru+0x23/0x5e > [] find_or_create_page+0x3f/0x62 > [] __getblk+0xfa/0x1cc > [] jread+0x110/0x1ed > [] do_one_pass+0xfc/0x476 > [] ? wake_bit_function+0x0/0x43 > [] journal_recover+0x7a/0x13d > [] ? buffer_uptodate+0xc/0xe > [] journal_load+0x42/0x76 > [] ext3_fill_super+0xd9c/0x1491 > > My bisection got this far: > > # good: [c813b4e1] Merge git://git.kernel.org/pub/scm/linux/kernel/gi > # bad: [a9b6148d] USB: Fix unused label warnings in drivers/usb/host > # bad: [656eb2cd] add CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS > # good: [bdbf0ac7] Merge branch 'hwmon-for-linus' of git://jdelvare.p > # good: [f7ea4a4b] Merge branch 'drm-next' of git://git.kernel.org/pu > # good: [556adecb] vmscan: second chance replacement for anonymous pa > # good: [28f74e71] hwmon/pc87360 separate alarm files: define some co > # good: [46d01a22] ext3: fix ext3 block reservation early ENOSPC issu > # good: [47c59803] devcgroup: remove spin_lock() > > The remaining bisection window of uncategorized commits is: > > nr of bisection commits: 14 > ---------------------------- > 656eb2c: add CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS > 6409324: coredump: format_corename: don't append .%pid if multi-threaded > b747c8c: make ptrace_untrace() static > c459643: bitmask: remove bitmap_scnprintf_len() > 30e8e13: cpuset: use seq_*mask_* to print masks > 3eda201: seq_file: add seq_cpumask_list(), seq_nodemask_list() > 85dd030: seq_file: don't call bitmap_scnprintf_len() > 40b6a76: cpuset.c: remove extra variable > 52d4b9a: memcg: allocate all page_cgroup at boot > c05555b: memcg: atomic ops for page_cgroup->flags > addb9ef: memcg: optimize per-cpu statistics > 5b4e655: memcg: avoid accounting special pages > b7abea9: memcg: make page->mapping NULL before uncharge > 073e587: memcg: move charge swapin under lock > > i'll poke in the middle - maybe i'm lucky and can find a > working/crashing tree to nudge the bisection back into life. Hi, Ingo, Li Zefan has reported this problem and Kamezawa is looking into it. I am unwell, I hope to look into the problem when I feel better or at-least in the intervals of time that I feel better. -- Balbir