lkml.org 
[lkml]   [2013]   [Feb]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Question on lockdep and MAX_LOCK_DEPTH
On 02/05/2013 05:54 PM, Steven Rostedt wrote:
> On Tue, Feb 05, 2013 at 05:10:37PM -0800, Ben Greear wrote:
>> I'm debugging something that could be my own bug in my wanlink module (but then
>> again, haven't seen this on 3.5 kernels, and my module is
>> basically un-changed since then).
>>
>> I'm using lockdep, and keep seeing "BUG: MAX_LOCK_DEPTH too low".
>> I tried changing the depth to 96 from 48, but it still hits.
>>
>> I also added debug_show_all_locks(); when this error
>> case hits. I was assuming that if lockdep depth is large,
>> there would be lots of locks held..but that does not
>> seem to be the case??

> Perhaps what you want to do is add a:
>
> lockdep_print_held_locks(current);

Well, here it is..something is calling rcu_read_lock lots and lots,
it seems. Any way to get a better idea of where those calls are
made?

Showing all locks held in the system:
1 lock held by mingetty/2868:
#0: (&tty->atomic_read_lock){+.+...}, at: [<ffffffff8132d503>] n_tty_read+0x28d/0x785
1 lock held by mingetty/2870:
#0: (&tty->atomic_read_lock){+.+...}, at: [<ffffffff8132d503>] n_tty_read+0x28d/0x785
1 lock held by mingetty/2872:
#0: (&tty->atomic_read_lock){+.+...}, at: [<ffffffff8132d503>] n_tty_read+0x28d/0x785
1 lock held by mingetty/2874:
#0: (&tty->atomic_read_lock){+.+...}, at: [<ffffffff8132d503>] n_tty_read+0x28d/0x785
1 lock held by mingetty/2876:
#0: (&tty->atomic_read_lock){+.+...}, at: [<ffffffff8132d503>] n_tty_read+0x28d/0x785
1 lock held by mingetty/2878:
#0: (&tty->atomic_read_lock){+.+...}, at: [<ffffffff8132d503>] n_tty_read+0x28d/0x785
1 lock held by bash/3337:
#0: (&tty->atomic_read_lock){+.+...}, at: [<ffffffff8132d503>] n_tty_read+0x28d/0x785
1 lock held by bash/3369:
#0: (&tty->atomic_read_lock){+.+...}, at: [<ffffffff8132d503>] n_tty_read+0x28d/0x785

=============================================

96 locks held by swapper/0/0:
#0: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#1: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#2: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#3: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#4: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#5: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#6: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#7: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#8: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#9: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#10: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#11: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#12: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#13: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#14: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#15: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#16: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#17: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#18: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#19: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#20: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#21: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#22: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#23: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#24: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#25: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#26: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#27: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#28: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#29: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#30: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#31: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#32: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#33: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#34: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#35: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#36: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#37: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#38: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#39: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#40: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#41: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#42: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#43: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#44: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#45: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#46: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#47: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#48: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#49: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#50: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#51: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#52: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#53: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#54: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#55: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#56: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#57: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#58: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#59: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#60: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#61: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#62: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#63: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#64: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#65: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#66: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#67: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#68: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#69: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#70: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#71: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#72: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#73: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#74: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#75: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#76: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#77: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#78: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#79: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#80: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#81: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#82: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#83: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#84: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#85: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#86: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#87: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#88: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#89: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#90: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#91: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#92: (rcu_read_lock){.+.+..}, at: [<ffffffff81476836>] rcu_read_lock+0x0/0x6f
#93: (&(&wl->cfg_spin_lock)->rlock){..-...}, at: [<ffffffffa07bc4d0>] handle_rcv+0x15d/0x1dd [wanlink]
#94: (&wl_threads[q].my_wq){..-...}, at: [<ffffffff810abe4d>] __wake_up+0x1d/0x48
#95: (&p->pi_lock){-.-.-.}, at: [<ffffffff810b09c1>] try_to_wake_up+0x29/0x20b
BUG: MAX_LOCK_DEPTH too low, depth: 96 max: 96!
turning off the locking correctness validator.
Pid: 0, comm: swapper/0 Tainted: G C O 3.7.6+ #6
Call Trace:
<IRQ> [<ffffffff810cda86>] __lock_acquire+0xe8d/0xf13
[<ffffffff810cc3e8>] ? mark_lock+0x2d/0x231
[<ffffffff810cdb70>] lock_acquire+0x64/0x81
[<ffffffff810b09c1>] ? try_to_wake_up+0x29/0x20b
[<ffffffff81540435>] _raw_spin_lock_irqsave+0x4e/0x60
[<ffffffff810b09c1>] ? try_to_wake_up+0x29/0x20b
[<ffffffff810b09c1>] try_to_wake_up+0x29/0x20b
[<ffffffff810b0bb0>] default_wake_function+0xd/0xf
[<ffffffff810ab34d>] __wake_up_common+0x49/0x7f
[<ffffffff810abe64>] __wake_up+0x34/0x48
[<ffffffffa07bbe11>] handleRcvWlp+0xf4d/0xfd5 [wanlink]
[<ffffffff810ccf7c>] ? __lock_acquire+0x383/0xf13
[<ffffffffa07bc325>] wp_handle_rcv_pkt+0x1f5/0x243 [wanlink]
[<ffffffffa07bc51c>] handle_rcv+0x1a9/0x1dd [wanlink]
[<ffffffff814777f5>] deliver_skb+0x58/0x60
[<ffffffff81477d04>] __netif_receive_skb+0x507/0x63c
[<ffffffff810100b6>] ? read_tsc+0x9/0x1b
[<ffffffff81479b3d>] netif_receive_skb+0x56/0x8b
[<ffffffff8147a168>] ? __napi_gro_receive+0xf3/0x102
[<ffffffff81479c55>] napi_skb_finish+0x24/0x57
[<ffffffff8147a39d>] napi_gro_receive+0x91/0x96
[<ffffffffa0218d31>] e1000_receive_skb+0x50/0x5b [e1000e]
[<ffffffffa021c00c>] e1000_clean_rx_irq+0x29f/0x341 [e1000e]
[<ffffffffa021c5c6>] e1000e_poll+0x7d/0x239 [e1000e]
[<ffffffff8147a523>] net_rx_action+0xb2/0x1e2
[<ffffffff8108ee06>] ? __do_softirq+0x6d/0x17b
[<ffffffff8108ee44>] __do_softirq+0xab/0x17b
[<ffffffff815473bc>] call_softirq+0x1c/0x30
[<ffffffff8100bd46>] do_softirq+0x46/0x9e
[<ffffffff8108ec9f>] irq_exit+0x4e/0xcc
[<ffffffff8100b635>] do_IRQ+0x97/0xae
[<ffffffff81540f72>] common_interrupt+0x72/0x72
<EOI> [<ffffffff81011082>] ? mwait_idle+0x77/0x9f
[<ffffffff81011079>] ? mwait_idle+0x6e/0x9f
[<ffffffff81011379>] cpu_idle+0x68/0xbc
[<ffffffff81522b4c>] rest_init+0x130/0x137
[<ffffffff81522a1c>] ? csum_partial_copy_generic+0x16c/0x16c
[<ffffffff81ac3c87>] start_kernel+0x37f/0x38c
[<ffffffff81ac373d>] ? repair_env_string+0x58/0x58
[<ffffffff81ac32dd>] x86_64_start_reservations+0xb8/0xbd
[<ffffffff81ac33e3>] x86_64_start_kernel+0x101/0x110
BUG: sleeping function called from invalid context at /home/greearb/git/linux-3.7.dev.y/kernel/mutex.c:269
in_atomic(): 0, irqs_disabled(): 0, pid: 2476, name: kwanlink/0
INFO: lockdep is turned off.
Pid: 2476, comm: kwanlink/0 Tainted: G C O 3.7.6+ #6
Call Trace:
[<ffffffff810ac9b0>] __might_sleep+0x1a2/0x1ab
[<ffffffff8153e549>] mutex_lock_nested+0x20/0x3b
[<ffffffffa07bd4ac>] do_task+0x6d/0x248 [wanlink]
[<ffffffffa07bd7e0>] wl_thread_task+0x159/0x202 [wanlink]
[<ffffffffa07bd687>] ? do_task+0x248/0x248 [wanlink]
[<ffffffff810a350b>] kthread+0xc2/0xca
[<ffffffff810a3449>] ? __init_kthread_worker+0x56/0x56
[<ffffffff8154607c>] ret_from_fork+0x7c/0xb0
[<ffffffff810a3449>] ? __init_kthread_worker+0x56/0x56
BUG: sleeping function called from invalid context at /home/greearb/git/linux-3.7.dev.y/kernel/mutex.c:269



--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc http://www.candelatech.com



\
 
 \ /
  Last update: 2013-02-06 04:01    [W:0.087 / U:6.520 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site