Re: [BUG] 2.6.28-git LOCKDEP: Possible recursive rq->lock

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

On Wed, 2009-01-07 at 17:59 +0530, Vaidyanathan Srinivasan wrote:

> =============================================
> [ INFO: possible recursive locking detected ]
> 2.6.28-autotest-tip-sv #1
> ---------------------------------------------
> klogd/5062 is trying to acquire lock:
>  (&rq->lock){++..}, at: [<ffffffff8022aca2>] task_rq_lock+0x45/0x7e
> 
> but task is already holding lock:
>  (&rq->lock){++..}, at: [<ffffffff805f7354>] schedule+0x158/0xa31
> 
> other info that might help us debug this:
> 1 lock held by klogd/5062:
>  #0:  (&rq->lock){++..}, at: [<ffffffff805f7354>] schedule+0x158/0xa31
> 
> stack backtrace:
> Pid: 5062, comm: klogd Not tainted 2.6.28-autotest-tip-sv #1
> Call Trace:
>  [<ffffffff80259ef1>] __lock_acquire+0xeb9/0x16a4
>  [<ffffffff8025a6c0>] ? __lock_acquire+0x1688/0x16a4
>  [<ffffffff8025a761>] lock_acquire+0x85/0xa9
>  [<ffffffff8022aca2>] ? task_rq_lock+0x45/0x7e
>  [<ffffffff805fa4d4>] _spin_lock+0x31/0x66
>  [<ffffffff8022aca2>] ? task_rq_lock+0x45/0x7e
>  [<ffffffff8022aca2>] task_rq_lock+0x45/0x7e
>  [<ffffffff80233363>] try_to_wake_up+0x88/0x27a
>  [<ffffffff80233581>] wake_up_process+0x10/0x12
>  [<ffffffff805f775c>] schedule+0x560/0xa31

I'd be most curious to know where in schedule we are.

Thanks