From: Ben Greear <greearb@candelatech.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>
Subject: Re: Question on lockdep and MAX_LOCK_DEPTH
Date: Tue, 05 Feb 2013 18:26:25 -0800 [thread overview]
Message-ID: <5111BF51.5010607@candelatech.com> (raw)
In-Reply-To: <20130206015430.GA9161@home.goodmis.org>
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
next prev parent reply other threads:[~2013-02-06 2:26 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-06 1:10 Question on lockdep and MAX_LOCK_DEPTH Ben Greear
2013-02-06 1:54 ` Steven Rostedt
2013-02-06 2:17 ` Ben Greear
2013-02-06 2:26 ` Ben Greear [this message]
2013-02-06 2:52 ` Steven Rostedt
2013-02-06 3:30 ` Ben Greear
2013-02-06 4:36 ` Steven Rostedt
2013-02-06 6:23 ` Ben Greear
2013-02-06 13:21 ` Steven Rostedt
2013-02-06 15:56 ` Ben Greear
2013-02-06 16:07 ` Steven Rostedt
2013-02-06 16:39 ` Ingo Molnar
2013-02-06 16:46 ` Steven Rostedt
2013-02-06 16:58 ` Ben Greear
2013-02-06 17:03 ` Steven Rostedt
2013-02-06 4:26 ` Steven Rostedt
2013-02-06 6:20 ` Ben Greear
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5111BF51.5010607@candelatech.com \
--to=greearb@candelatech.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.