Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753861Ab0AJRX3 (ORCPT ); Sun, 10 Jan 2010 12:23:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753818Ab0AJRX3 (ORCPT ); Sun, 10 Jan 2010 12:23:29 -0500 Received: from out01.mta.xmission.com ([166.70.13.231]:53831 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753725Ab0AJRX2 convert rfc822-to-8bit (ORCPT ); Sun, 10 Jan 2010 12:23:28 -0500 To: =?utf-8?Q?Am=C3=A9rico?= Wang Cc: Miles Lane , LKML , Greg Kroah-Hartman , Jesse Barnes , Len Brown , Pavel Machek , "Rafael J. Wysocki" Subject: Re: 2.6.33-rc3 -- INFO: possible recursive locking -- (s_active){++++.+}, at: [] sysfs_hash_and_remove+0x3d/0x4f References: <20100110084704.GC3005@hack> <2375c9f91001100058w4bac1cf9s183fc37eafbfde75@mail.gmail.com> From: ebiederm@xmission.com (Eric W. Biederman) Date: Sun, 10 Jan 2010 09:23:15 -0800 In-Reply-To: <2375c9f91001100058w4bac1cf9s183fc37eafbfde75@mail.gmail.com> (=?utf-8?Q?=22Am=C3=A9rico?= Wang"'s message of "Sun\, 10 Jan 2010 16\:58\:56 +0800") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Scanned: No (on in01.mta.xmission.com); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4443 Lines: 93 Américo Wang writes: > On Sun, Jan 10, 2010 at 4:47 PM, Américo Wang wrote: >> >> On Wed, Jan 06, 2010 at 07:54:59AM -0500, Miles Lane wrote: >> >[ 6967.926563] ACPI: Preparing to enter system sleep state S3 >> >[ 6967.956156] Disabling non-boot CPUs ... >> >[ 6967.970401] >> >[ 6967.970408] ============================================= >> >[ 6967.970419] [ INFO: possible recursive locking detected ] >> >[ 6967.970431] 2.6.33-rc2-git6 #27 >> >[ 6967.970439] --------------------------------------------- >> >[ 6967.970450] pm-suspend/22147 is trying to acquire lock: >> >[ 6967.970460] (s_active){++++.+}, at: [] >> >sysfs_hash_and_remove+0x3d/0x4f >> >[ 6967.970493] >> >[ 6967.970497] but task is already holding lock: >> >[ 6967.970506] (s_active){++++.+}, at: [] >> >sysfs_get_active_two+0x16/0x36 >> >[ 6967.970531] >> >[ 6967.970535] other info that might help us debug this: >> >[ 6967.970547] 6 locks held by pm-suspend/22147: >> >[ 6967.970556] #0: (&buffer->mutex){+.+.+.}, at: [] >> >sysfs_write_file+0x25/0xeb >> >[ 6967.970584] #1: (s_active){++++.+}, at: [] >> >sysfs_get_active_two+0x16/0x36 >> >[ 6967.970612] #2: (s_active){++++.+}, at: [] >> >sysfs_get_active_two+0x21/0x36 >> >[ 6967.970639] #3: (pm_mutex){+.+.+.}, at: [] enter_state+0x26/0x114 >> >[ 6967.970668] #4: (cpu_add_remove_lock){+.+.+.}, at: [] >> >cpu_maps_update_begin+0xf/0x11 >> >[ 6967.970697] #5: (cpu_hotplug.lock){+.+.+.}, at: [] >> >cpu_hotplug_begin+0x1d/0x40 >> >[ 6967.970724] >> >[ 6967.970728] stack backtrace: >> >[ 6967.970740] Pid: 22147, comm: pm-suspend Not tainted 2.6.33-rc2-git6 #27 >> >[ 6967.970751] Call Trace: >> >[ 6967.970771] [] ? printk+0xf/0x18 >> >[ 6967.970791] [] __lock_acquire+0x817/0xb6d >> >[ 6967.970812] [] ? mark_held_locks+0x43/0x5b >> >[ 6967.970831] [] ? debug_check_no_locks_freed+0xfd/0x107 >> >[ 6967.970851] [] ? trace_hardirqs_on_caller+0x108/0x130 >> >[ 6967.970871] [] lock_acquire+0x5c/0x73 >> >[ 6967.970890] [] ? sysfs_hash_and_remove+0x3d/0x4f >> >[ 6967.970910] [] sysfs_addrm_finish+0x9a/0xfe >> >[ 6967.970929] [] ? sysfs_hash_and_remove+0x3d/0x4f >> >[ 6967.970953] [] sysfs_hash_and_remove+0x3d/0x4f >> >[ 6967.970974] [] sysfs_remove_group+0x52/0x81 >> >[ 6967.970993] [] mc_cpu_callback+0x73/0x9a >> >[ 6967.971014] [] notifier_call_chain+0x51/0x78 >> >[ 6967.971034] [] __raw_notifier_call_chain+0xe/0x10 >> >[ 6967.971054] [] _cpu_down+0x7a/0x235 >> >[ 6967.971074] [] disable_nonboot_cpus+0x58/0xe0 >> >[ 6967.971093] [] suspend_devices_and_enter+0xb9/0x173 >> >[ 6967.971094] [] enter_state+0xc8/0x114 >> >[ 6967.971094] [] state_store+0x93/0xa7 >> >[ 6967.971094] [] ? state_store+0x0/0xa7 >> >[ 6967.971094] [] kobj_attr_store+0x16/0x22 >> >[ 6967.971094] [] sysfs_write_file+0xc0/0xeb >> >[ 6967.971094] [] ? sysfs_write_file+0x0/0xeb >> >[ 6967.971094] [] vfs_write+0x80/0xdf >> >[ 6967.971094] [] sys_write+0x3b/0x5d >> >[ 6967.971094] [] sysenter_do_call+0x12/0x36 >> >[ 6967.973262] CPU 1 is now offline >> >[ 6967.973271] lockdep: fixing up alternatives. >> >> Hmmm, does reverting commit 846f99749ab68b help? >> > > Of course it will help, but the problem is not that. That patch helps > us to detect such a problem... I am still investigating. :-/ This looks like this is triggered by a write to a sysfs file, so the solution is probably to call schedule_work so the suspend can happen outside the context of sysfs. The typical scenario that triggers this is: - A lock is held while removing a sysfs attribute. - The same lock is grabbed inside the sysfs attribute. I think we do that with the cpu_hotplug.lock In this case it looks like this might be a reach around scenario where we try and remove the sysfs attribute that triggered the suspend. Eric -- 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/