From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752154AbZEQHTN (ORCPT ); Sun, 17 May 2009 03:19:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751704AbZEQHS4 (ORCPT ); Sun, 17 May 2009 03:18:56 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:56542 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750834AbZEQHSz (ORCPT ); Sun, 17 May 2009 03:18:55 -0400 Date: Sun, 17 May 2009 09:18:34 +0200 From: Ingo Molnar To: Zdenek Kabelac , "Rafael J. Wysocki" , Peter Zijlstra , Oleg Nesterov Cc: Linux Kernel Mailing List Subject: Re: INFO: possible circular locking dependency at cleanup_workqueue_thread Message-ID: <20090517071834.GA8507@elte.hu> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Cc:s added. This dependency: > -> #2 (cfg80211_mutex){+.+.+.}: > [] __lock_acquire+0xc64/0x10a0 > [] lock_acquire+0x98/0x140 > [] __mutex_lock_common+0x4c/0x3b0 > [] mutex_lock_nested+0x46/0x60 > [] reg_todo+0x19a/0x590 [cfg80211] > [] worker_thread+0x1e8/0x3a0 > [] kthread+0x5a/0xa0 > [] child_rip+0xa/0x20 is what sets the dependencies upside down. Ingo * Zdenek Kabelac wrote: > Hi > > With this kernel a4d7749be5de4a7261bcbe3c7d96c748792ec455 > > I've got this INFO trace during suspend: > > > CPU 1 is now offline > lockdep: fixing up alternatives. > SMP alternatives: switching to UP code > CPU0 attaching NULL sched-domain. > CPU1 attaching NULL sched-domain. > CPU0 attaching NULL sched-domain. > > ======================================================= > [ INFO: possible circular locking dependency detected ] > 2.6.30-rc5-00097-gd665355 #59 > ------------------------------------------------------- > pm-suspend/12129 is trying to acquire lock: > (events){+.+.+.}, at: [] cleanup_workqueue_thread+0x26/0xd0 > > but task is already holding lock: > (cpu_add_remove_lock){+.+.+.}, at: [] > cpu_maps_update_begin+0x17/0x20 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #5 (cpu_add_remove_lock){+.+.+.}: > [] __lock_acquire+0xc64/0x10a0 > [] lock_acquire+0x98/0x140 > [] __mutex_lock_common+0x4c/0x3b0 > [] mutex_lock_nested+0x46/0x60 > [] cpu_maps_update_begin+0x17/0x20 > [] __create_workqueue_key+0xc3/0x250 > [] stop_machine_create+0x40/0xb0 > [] sys_delete_module+0x84/0x270 > [] system_call_fastpath+0x16/0x1b > [] 0xffffffffffffffff > > -> #4 (setup_lock){+.+.+.}: > [] __lock_acquire+0xc64/0x10a0 > [] lock_acquire+0x98/0x140 > [] __mutex_lock_common+0x4c/0x3b0 > [] mutex_lock_nested+0x46/0x60 > [] stop_machine_create+0x17/0xb0 > [] disable_nonboot_cpus+0x26/0x130 > [] suspend_devices_and_enter+0xbd/0x1b0 > [] enter_state+0x107/0x170 > [] state_store+0x99/0x100 > [] kobj_attr_store+0x17/0x20 > [] sysfs_write_file+0xd9/0x160 > [] vfs_write+0xb8/0x180 > [] sys_write+0x51/0x90 > [] system_call_fastpath+0x16/0x1b > [] 0xffffffffffffffff > > -> #3 (dpm_list_mtx){+.+.+.}: > [] __lock_acquire+0xc64/0x10a0 > [] lock_acquire+0x98/0x140 > [] __mutex_lock_common+0x4c/0x3b0 > [] mutex_lock_nested+0x46/0x60 > [] device_pm_add+0x1f/0xe0 > [] device_add+0x45f/0x570 > [] wiphy_register+0x158/0x280 [cfg80211] > [] ieee80211_register_hw+0xbc/0x410 [mac80211] > [] iwl3945_pci_probe+0xa1c/0x1080 [iwl3945] > [] local_pci_probe+0x17/0x20 > [] pci_device_probe+0x88/0xb0 > [] driver_probe_device+0x89/0x180 > [] __driver_attach+0x9b/0xa0 > [] bus_for_each_dev+0x6c/0xa0 > [] driver_attach+0x1e/0x20 > [] bus_add_driver+0xd5/0x290 > [] driver_register+0x78/0x140 > [] __pci_register_driver+0x66/0xe0 > [] 0xffffffffa00bd05c > [] do_one_initcall+0x3f/0x1c0 > [] sys_init_module+0xb1/0x200 > [] system_call_fastpath+0x16/0x1b > [] 0xffffffffffffffff > > -> #2 (cfg80211_mutex){+.+.+.}: > [] __lock_acquire+0xc64/0x10a0 > [] lock_acquire+0x98/0x140 > [] __mutex_lock_common+0x4c/0x3b0 > [] mutex_lock_nested+0x46/0x60 > [] reg_todo+0x19a/0x590 [cfg80211] > [] worker_thread+0x1e8/0x3a0 > [] kthread+0x5a/0xa0 > [] child_rip+0xa/0x20 > [] 0xffffffffffffffff > > -> #1 (reg_work){+.+.+.}: > [] __lock_acquire+0xc64/0x10a0 > [] lock_acquire+0x98/0x140 > [] worker_thread+0x1e2/0x3a0 > [] kthread+0x5a/0xa0 > [] child_rip+0xa/0x20 > [] 0xffffffffffffffff > > -> #0 (events){+.+.+.}: > [] __lock_acquire+0xd36/0x10a0 > [] lock_acquire+0x98/0x140 > [] cleanup_workqueue_thread+0x4d/0xd0 > [] workqueue_cpu_callback+0xc9/0x10f > [] notifier_call_chain+0x68/0xa0 > [] raw_notifier_call_chain+0x16/0x20 > [] _cpu_down+0x1cc/0x2d0 > [] disable_nonboot_cpus+0xb0/0x130 > [] suspend_devices_and_enter+0xbd/0x1b0 > [] enter_state+0x107/0x170 > [] state_store+0x99/0x100 > [] kobj_attr_store+0x17/0x20 > [] sysfs_write_file+0xd9/0x160 > [] vfs_write+0xb8/0x180 > [] sys_write+0x51/0x90 > [] system_call_fastpath+0x16/0x1b > [] 0xffffffffffffffff > > other info that might help us debug this: > > 4 locks held by pm-suspend/12129: > #0: (&buffer->mutex){+.+.+.}, at: [] > sysfs_write_file+0x44/0x160 > #1: (pm_mutex){+.+.+.}, at: [] enter_state+0x54/0x170 > #2: (dpm_list_mtx){+.+.+.}, at: [] device_pm_lock+0x17/0x20 > #3: (cpu_add_remove_lock){+.+.+.}, at: [] > cpu_maps_update_begin+0x17/0x20 > > stack backtrace: > Pid: 12129, comm: pm-suspend Not tainted 2.6.30-rc5-00097-gd665355 #59 > Call Trace: > [] print_circular_bug_tail+0x9d/0xe0 > [] __lock_acquire+0xd36/0x10a0 > [] ? mark_lock+0x3e0/0x400 > [] lock_acquire+0x98/0x140 > [] ? cleanup_workqueue_thread+0x26/0xd0 > [] cleanup_workqueue_thread+0x4d/0xd0 > [] ? cleanup_workqueue_thread+0x26/0xd0 > [] ? trace_hardirqs_on+0xd/0x10 > [] workqueue_cpu_callback+0xc9/0x10f > [] ? cpu_callback+0x12/0x280 > [] notifier_call_chain+0x68/0xa0 > [] raw_notifier_call_chain+0x16/0x20 > [] _cpu_down+0x1cc/0x2d0 > [] disable_nonboot_cpus+0xb0/0x130 > [] suspend_devices_and_enter+0xbd/0x1b0 > [] enter_state+0x107/0x170 > [] state_store+0x99/0x100 > [] kobj_attr_store+0x17/0x20 > [] sysfs_write_file+0xd9/0x160 > [] vfs_write+0xb8/0x180 > [] ? audit_syscall_entry+0x21c/0x240 > [] sys_write+0x51/0x90 > [] system_call_fastpath+0x16/0x1b > CPU1 is down > Extended CMOS year: 2000 > x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106 > Back to C! > -- > 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/