Re: APM lockups since 2.6.25

[Mikulas Patocka]

On Fri, 21 Mar 2008, Rafael J. Wysocki wrote:

> On Friday, 21 of March 2008, Mikulas Patocka wrote:
> > Hi
> 
> Hi,
>   
> > > > I have an old notebook with APM and I am experiencing occasional APMD 
> > > > lockups after resume, with kernels 2.6.25rc1 snd 2.6.25rc3. They didn't 
> > > > happen with 2.6.24 or before.
> > > > 
> > > > The bug happens about once a week or so.
> > > > 
> > > > If you have any idea how to debug it, you can send me a test code.
> > > 
> > > It is possible that the bug was fixed in -rc4.  Can you please test -rc6 and
> > > see if it's still present?
> > > 
> > > Thanks,
> > > Rafael
> > 
> > I'm now running on -rc6, so I'll see (it takes some days for the bug to 
> > appear). Where is that patch that went to -rc4 and that may fix it?
> 
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7a8d37a37380e2b1500592d40b7ec384dbebe7a0
> 
> Thanks,
> Rafael

So it didn't help, I just got this (2.6.25-rc8):

(I have turned lockdep on few days ago, and it seems to try to release a 
lock that's not held ... and then reacquire that lock again and deadlock)

=====================================
[ BUG: bad unlock balance detected! ]
-------------------------------------
kapmd/1643 is trying to release lock (pm_sleep_rwsem) at:
[<c01e3a75>] device_resume+0x129/0x12e
but there are no more locks to release!

other info that might help us debug this:
no locks held by kapmd/1643.

stack backtrace:
Pid: 1643, comm: kapmd Not tainted 2.6.25-rc8 #5
 [<c012f877>] print_unlock_inbalance_bug+0xd7/0xe1
 [<c0241465>] ? _spin_unlock_irqrestore+0x36/0x58
 [<c012e6d5>] ? trace_hardirqs_on+0xdf/0x100
 [<c012e560>] ? mark_held_locks+0x4e/0x66
 [<c024002c>] ? mutex_lock_nested+0x1f3/0x217
 [<c012e6d5>] ? trace_hardirqs_on+0xdf/0x100
 [<c01e3a75>] ? device_resume+0x129/0x12e
 [<c012fa36>] lock_release+0x90/0x132
 [<c0127f6c>] up_write+0x16/0x2a
 [<c01e3a75>] device_resume+0x129/0x12e
 [<c884e251>] apm+0x457/0x523 [apm]
 [<c01110a1>] ? default_wake_function+0x0/0xd
 [<c884ddfa>] ? apm+0x0/0x523 [apm]
 [<c0124cd5>] kthread+0x39/0x5e
 [<c0124c9c>] ? kthread+0x0/0x5e
 [<c0102fdf>] kernel_thread_helper+0x7/0x10
 =======================
INFO: task apmd:1813 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
apmd          D c6cb0260  2320  1813      1
       c7b06ea8 00000046 c6cb0000 c6cb0260 c003f081 0000a086 c6d13980 
c6cb0260
       c02e724c c02e724c ffffffff c79f1b60 c02e7248 c7b06ed0 c0240e71 
c7b06ed8
       c02e724c c02e7268 c6cb0000 c7b06eec c02e7248 c79f1b60 00000000 
c7b06eec
Call Trace:
 [<c0240e71>] rwsem_down_failed_common+0x122/0x140
 [<c0240eaa>] rwsem_down_write_failed+0x1b/0x23
 [<c0240f2a>] call_rwsem_down_write_failed+0x6/0x8
 [<c0240502>] ? down_write+0x3b/0x43
 [<c01e3a9f>] ? device_suspend+0x25/0x1ac
 [<c01e3a9f>] device_suspend+0x25/0x1ac
 [<c884d624>] suspend+0x66/0x12e [apm]
 [<c884d95a>] do_ioctl+0xd3/0x14b [apm]
 [<c0161588>] vfs_ioctl+0x50/0x69
 [<c01617e6>] do_vfs_ioctl+0x245/0x258
 [<c0161825>] sys_ioctl+0x2c/0x47
 [<c0102cd2>] syscall_call+0x7/0xb
 =======================
INFO: lockdep is turned off.

Mikulas
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