From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Jenkins Subject: INFO: possible circular locking detected [when unloading the bonding driver] Date: Sun, 13 Sep 2009 13:26:22 +0100 Message-ID: <4AACE4EE.4080707@tuffmail.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: linux-kernel , netdev@vger.kernel.org, bonding-devel@lists.sourceforge.net To: Jay Vosburgh Return-path: Received: from mail-ew0-f206.google.com ([209.85.219.206]:44349 "EHLO mail-ew0-f206.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753305AbZIMM0X (ORCPT ); Sun, 13 Sep 2009 08:26:23 -0400 Sender: netdev-owner@vger.kernel.org List-ID: I found this warning after loading and unloading all the modules I had available. I can reproduce it by hibernating the system, then loading and unloading the bonding module. Regards Alan [ 123.484225] Ethernet Channel Bonding Driver: v3.5.0 (November 4, 2008) [ 123.484229] bonding: Warning: either miimon or arp_interval and arp_ip_target module parameters must be specified, otherwise bonding will not detect link failures! see bonding.txt for details. [ 125.790929] [ 125.790931] ======================================================= [ 125.790936] [ INFO: possible circular locking dependency detected ] [ 125.790940] 2.6.31-rc8debug #50 [ 125.790942] ------------------------------------------------------- [ 125.790946] modprobe/8372 is trying to acquire lock: [ 125.790948] (cpu_add_remove_lock){+.+.+.}, at: [] cpu_maps_update_begin+0x12/0x20 [ 125.790961] [ 125.790962] but task is already holding lock: [ 125.790965] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x12/0x20 [ 125.790974] [ 125.790975] which lock already depends on the new lock. [ 125.790976] [ 125.790978] [ 125.790979] the existing dependency chain (in reverse order) is: [ 125.790982] [ 125.790983] -> #3 (rtnl_mutex){+.+.+.}: [ 125.790989] [] validate_chain+0xb99/0x11d0 [ 125.790996] [] __lock_acquire+0x35e/0xa30 [ 125.791001] [] lock_acquire+0x97/0x110 [ 125.791006] [] mutex_lock_nested+0x56/0x310 [ 125.791012] [] rtnl_lock+0x12/0x20 [ 125.791016] [] linkwatch_event+0x9/0x40 [ 125.791021] [] worker_thread+0x23a/0x350 [ 125.791027] [] kthread+0xa6/0xb0 [ 125.791032] [] child_rip+0xa/0x20 [ 125.791037] [] 0xffffffffffffffff [ 125.791051] [ 125.791052] -> #2 ((linkwatch_work).work){+.+.+.}: [ 125.791058] [] validate_chain+0xb99/0x11d0 [ 125.791063] [] __lock_acquire+0x35e/0xa30 [ 125.791068] [] lock_acquire+0x97/0x110 [ 125.791073] [] worker_thread+0x234/0x350 [ 125.791077] [] kthread+0xa6/0xb0 [ 125.791082] [] child_rip+0xa/0x20 [ 125.791087] [] 0xffffffffffffffff [ 125.791092] [ 125.791093] -> #1 (events){+.+.+.}: [ 125.791098] [] validate_chain+0xb99/0x11d0 [ 125.791104] [] __lock_acquire+0x35e/0xa30 [ 125.791108] [] lock_acquire+0x97/0x110 [ 125.791114] [] cleanup_workqueue_thread+0x48/0xd0 [ 125.791119] [] workqueue_cpu_callback+0x9a/0x130 [ 125.791125] [] notifier_call_chain+0x5e/0xa0 [ 125.791130] [] __raw_notifier_call_chain+0x9/0x10 [ 125.791136] [] raw_notifier_call_chain+0x11/0x20 [ 125.791141] [] _cpu_down+0x173/0x2b0 [ 125.791145] [] disable_nonboot_cpus+0x98/0x130 [ 125.791150] [] hibernation_snapshot+0x187/0x250 [ 125.791156] [] hibernate+0x118/0x1c0 [ 125.791160] [] state_store+0xd3/0xf0 [ 125.791165] [] kobj_attr_store+0x17/0x20 [ 125.791172] [] sysfs_write_file+0xf4/0x150 [ 125.791178] [] vfs_write+0xc7/0x1a0 [ 125.791184] [] sys_write+0x50/0x90 [ 125.791189] [] system_call_fastpath+0x16/0x1b [ 125.791194] [] 0xffffffffffffffff [ 125.791205] [ 125.791205] -> #0 (cpu_add_remove_lock){+.+.+.}: [ 125.791211] [] validate_chain+0x5cd/0x11d0 [ 125.791216] [] __lock_acquire+0x35e/0xa30 [ 125.791221] [] lock_acquire+0x97/0x110 [ 125.791225] [] mutex_lock_nested+0x56/0x310 [ 125.791230] [] cpu_maps_update_begin+0x12/0x20 [ 125.791235] [] destroy_workqueue+0x22/0xc0 [ 125.791240] [] bond_uninit+0x3a/0x70 [bonding] [ 125.791252] [] rollback_registered+0xbd/0x120 [ 125.791258] [] unregister_netdevice+0x1d/0x70 [ 125.791262] [] bond_free_all+0x4f/0xa0 [bonding] [ 125.791273] [] bonding_exit+0x35/0x3c [bonding] [ 125.791283] [] sys_delete_module+0x176/0x230 [ 125.791288] [] system_call_fastpath+0x16/0x1b [ 125.791293] [] 0xffffffffffffffff [ 125.791298] [ 125.791299] other info that might help us debug this: [ 125.791300] [ 125.791304] 1 lock held by modprobe/8372: [ 125.791306] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x12/0x20 [ 125.791314] [ 125.791315] stack backtrace: [ 125.791319] Pid: 8372, comm: modprobe Not tainted 2.6.31-rc8debug #50 [ 125.791322] Call Trace: [ 125.791328] [] print_circular_bug_tail+0x94/0xe0 [ 125.791333] [] validate_chain+0x5cd/0x11d0 [ 125.791338] [] __lock_acquire+0x35e/0xa30 [ 125.791343] [] lock_acquire+0x97/0x110 [ 125.791349] [] ? cpu_maps_update_begin+0x12/0x20 [ 125.791354] [] mutex_lock_nested+0x56/0x310 [ 125.791358] [] ? cpu_maps_update_begin+0x12/0x20 [ 125.791363] [] ? release_sysfs_dirent+0x54/0xc0 [ 125.791368] [] cpu_maps_update_begin+0x12/0x20 [ 125.791373] [] destroy_workqueue+0x22/0xc0 [ 125.791383] [] bond_uninit+0x3a/0x70 [bonding] [ 125.791388] [] rollback_registered+0xbd/0x120 [ 125.791397] [] ? bond_work_cancel_all+0x16/0x130 [bonding] [ 125.791402] [] unregister_netdevice+0x1d/0x70 [ 125.791411] [] bond_free_all+0x4f/0xa0 [bonding] [ 125.791421] [] bonding_exit+0x35/0x3c [bonding] [ 125.791425] [] sys_delete_module+0x176/0x230 [ 125.791430] [] ? trace_hardirqs_on_caller+0x14d/0x1a0 [ 125.791435] [] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 125.791441] [] system_call_fastpath+0x16/0x1b