Re: [PATCH 1/2] workqueue: Catch more locking problems withflush_work()

[Yong Zhang]

On Thu, Apr 19, 2012 at 11:36:32AM -0700, Stephen Boyd wrote:
> Does looking at the second patch help? Basically schedule_work() can run
> the callback right between the time the mutex is acquired and
> flush_work() is called:
> 
> CPU0                        CPU1
> 
> <irq>
>   schedule_work()           mutex_lock(&mutex)
> <irq return>
>     my_work()               flush_work() 
>       mutex_lock(&mutex)    
>       <deadlock>

Get you point. It is a problem. But your patch could introduece false
positive since when flush_work() is called that very work may finish
running already.

So I think we need the lock_map_acquire()/lock_map_release() only when
the work is under processing, no?

Thanks,
Yong
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