Re: [2.6.33-rc5] Weird deadlock when shutting down

["Américo Wang" <xiyou.wangcong@gmail.com>]

On Thu, Feb 18, 2010 at 5:36 PM, Johannes Berg
<johannes@sipsolutions.net> wrote:
> On Fri, 2010-01-29 at 15:41 +1100, Benjamin Herrenschmidt wrote:
>> Hi Ingo !
>>
>> Johannes and I see this on our quad G5s... it -could- be similar to
>> one reported a short while ago by Xiaotian Feng <xtfeng@gmail.com>
>> under the subject [2.6.33-rc4] sysfs lockdep warnings on cpu hotplug.
>>
>> Basically, the machine deadlocks right after printing the following
>> when doing a shutdown:
>>
>> halt/4071 is trying to acquire lock:
>>  (s_active){++++.+}, at: [<c0000000001ef868>]
>> .sysfs_addrm_finish+0x58/0xc0
>>
>> but task is already holding lock:
>>  (&per_cpu(cpu_policy_rwsem, cpu)){+.+.+.}, at: [<c0000000004cd6ac>]
>> .lock_policy_rwsem_write+0x84/0xf4
>>
>> which lock already depends on the new lock.
>>
>> the existing dependency chain (in reverse order) is:
>
> This is still happening with -rc8. Any news?
>

Hey, johannes

Not sure if you made some mistake here, the one you report here [1]
is _not_ the same with this one reported by Benjamin.

Please make sure what you are talking about here is the same one.

Thanks.

1. http://lkml.org/lkml/2010/2/18/33