workqueues - how to use them correctly

Anish Kumar anish198519851985 at gmail.com
Tue Feb 10 12:24:46 EST 2015





> On Feb 10, 2015, at 12:50 AM, Roshan A <roshan.len at gmail.com> wrote:
> 
> hi all,
> 
> My question is regarding the correct use of workqueues. I have a
> driver which queues a work item in the interrupt handler. The bottom
> half function ( the workitem -function ) does have proper locking (
> mutex ) in place for atomicity.

Post the code snippet and why are you using
Mutex? If you want to synchronize between 
Interrupt handler and workqueue then you should
use spinlocks.
> 
> With this setup, since the interrupts are enabled, it's possible to
> have a scenario where, when one workitem is being executed, another
> can be queued up, which results in the workitems being executed in
> parallel, however since there is a mutex, one thread will sleep.

And precisely the reason not to use mutex locks.
> 
> is this particular scenario considered bad or discouraged ?

Now what do you think?
> 
> Thank you,
> -Roshan
> 
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