2.6.33-rc3-mmotm0106 - BUG: MAX_LOCKDEP_KEYS too low!

2.6.33-rc3-mmotm0106 - BUG: MAX_LOCKDEP_KEYS too low!

[Valdis.Kletnieks]

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Seen in my dmesg output - I wasn't even home at the time, so my
laptop was basically idle.

[ 7777.019267] dell-wmi: Received unknown WMI event (0x11)
[ 8190.620401] BUG: MAX_LOCKDEP_KEYS too low!
[ 8190.620406] turning off the locking correctness validator.
[ 8190.620410] Pid: 4266, comm: firefox-bin Not tainted 2.6.33-rc3-mmotm0106 #8
[ 8190.620412] Call Trace:
[ 8190.620421]  [<ffffffff81064253>] register_lock_class+0x152/0x31f
[ 8190.620425]  [<ffffffff81065c9e>] __lock_acquire+0xbd/0xcfa
[ 8190.620430]  [<ffffffff810d41c7>] ? spin_lock+0x9/0xb
[ 8190.620434]  [<ffffffff810d40ef>] ? trace_kmalloc+0x3d/0x8c
[ 8190.620439]  [<ffffffff811bcebb>] ? kzalloc+0xf/0x11
[ 8190.620444]  [<ffffffff812105b3>] ? __percpu_counter_add+0x57/0xb4
[ 8190.620447]  [<ffffffff810669a6>] lock_acquire+0xcb/0xe8
[ 8190.620451]  [<ffffffff812105b3>] ? __percpu_counter_add+0x57/0xb4
[ 8190.620455]  [<ffffffff81065509>] ? debug_check_no_locks_freed+0x11a/0x12a
[ 8190.620460]  [<ffffffff81564ba9>] _raw_spin_lock+0x36/0x45
[ 8190.620464]  [<ffffffff812105b3>] ? __percpu_counter_add+0x57/0xb4
[ 8190.620468]  [<ffffffff812105b3>] __percpu_counter_add+0x57/0xb4
[ 8190.620473]  [<ffffffff814872d4>] tcp_v4_init_sock+0x18e/0x199
[ 8190.620477]  [<ffffffff81496cd7>] inet_create+0x31f/0x34a
[ 8190.620482]  [<ffffffff8142f9ba>] __sock_create+0x15d/0x1e5
[ 8190.620485]  [<ffffffff8142f954>] ? __sock_create+0xf7/0x1e5
[ 8190.620489]  [<ffffffff8142fa8e>] sock_create+0x2b/0x2d
[ 8190.620492]  [<ffffffff8142fc8b>] sys_socket+0x26/0x57
[ 8190.620497]  [<ffffffff810023ab>] system_call_fastpath+0x16/0x1b
[ 8438.412037] dell-wmi: Received unknown WMI event (0x11)

Triggered it another time as well at system shutdown:

[10912.842284] BUG: MAX_LOCKDEP_KEYS too low!
[10912.843251] turning off the locking correctness validator.
[10912.843251] Pid: 997, comm: hd-audio0 Not tainted 2.6.33-rc3-mmotm0106 #8
[10912.843251] Call Trace:
[10912.850465]  [<ffffffff81064253>] register_lock_class+0x152/0x31f
[10912.850465]  [<ffffffff81064f0c>] ? mark_lock+0x2d/0x226
[10912.850465]  [<ffffffff81065c9e>] __lock_acquire+0xbd/0xcfa
[10912.850465]  [<ffffffff8102dc35>] ? get_parent_ip+0x11/0x42
[10912.850465]  [<ffffffff81050193>] ? spin_lock_irq+0x9/0xb
[10912.850465]  [<ffffffff810514f5>] ? worker_thread+0x205/0x38b
[10912.850465]  [<ffffffff810669a6>] lock_acquire+0xcb/0xe8
[10912.850465]  [<ffffffff810514f5>] ? worker_thread+0x205/0x38b
[10912.850465]  [<ffffffff81051548>] worker_thread+0x258/0x38b
[10912.850465]  [<ffffffff810514f5>] ? worker_thread+0x205/0x38b
[10912.850465]  [<ffffffff8141ca37>] ? process_unsol_events+0x0/0x62
[10912.850465]  [<ffffffff81054c3d>] ? autoremove_wake_function+0x0/0x34
[10912.850465]  [<ffffffff810512f0>] ? worker_thread+0x0/0x38b
[10912.850465]  [<ffffffff8105477f>] kthread+0x7a/0x82
[10912.850465]  [<ffffffff810031d4>] kernel_thread_helper+0x4/0x10
[10912.850465]  [<ffffffff81565b00>] ? restore_args+0x0/0x30
[10912.850465]  [<ffffffff81054705>] ? kthread+0x0/0x82
[10912.850465]  [<ffffffff810031d0>] ? kernel_thread_helper+0x0/0x10

If I'm hitting MAX_LOCKDEP_KEYS after just a few hours on a mostly-idle
laptop, should it be set higher?

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Re: 2.6.33-rc3-mmotm0106 - BUG: MAX_LOCKDEP_KEYS too low!

[Peter Zijlstra]

On Wed, 2010-01-13 at 01:22 -0500, Valdis.Kletnieks@vt.edu wrote:
> Seen in my dmesg output - I wasn't even home at the time, so my
> laptop was basically idle.
> 
> [ 7777.019267] dell-wmi: Received unknown WMI event (0x11)
> [ 8190.620401] BUG: MAX_LOCKDEP_KEYS too low!

> If I'm hitting MAX_LOCKDEP_KEYS after just a few hours on a mostly-idle
> laptop, should it be set higher?

I'm wondering what's eating all those classes, it there a lot of module
loading/unloading happening?

Does something like the below give any clues?

---
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 5feaddc..90b9428 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -761,6 +761,7 @@ register_lock_class(struct lockdep_map *lock,
unsigned int subclass, int force)
 	debug_atomic_inc(&nr_unused_locks);
 	class->key = key;
 	class->name = lock->name;
+	printk(KERN_EMERG "LOCK CLASS: %s\n", lock->name);
 	class->subclass = subclass;
 	INIT_LIST_HEAD(&class->lock_entry);
 	INIT_LIST_HEAD(&class->locks_before);