Re: [RFC] Input: serio - convert to use workqueue instead of a thread

[Tejun Heo <tj@kernel.org>]

Hello,

On 09/15/2010 07:16 AM, Dmitry Torokhov wrote:
> Instead of creating an exclusive thread to handle serio events (which
> happen rarely), let's switch to using a workqueue. With the arrival of
> concurrency-managed workqueue infrastructure it should reduce total
> number of threads in the system.
> 
> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
> ---
> 
> If this makes sense I have a similar patch for gameport... Hopefully
> this will allow to get rid of kseriod, kgameportd, kpsmoused and
> ipolldevd...

Generally looks good to me.  Just some deatils.

> +	serio_wq = alloc_workqueue("kseriod", WQ_UNBOUND, 1);

I don't think there's any need to use WQ_UNBOUND + @max_active of 1.
The event handler seems to be handling synchornization itself and the
there's single work item.

Also, there's no reason to use a separate workqueue at all.  Just
schedule_work() and do cancel_work_sync() on serio_exit().  With the
worker pool sharing, there's no latency or execution advantage to
using a separate workqueue anymore unless you need a rescuer or want
to have a separate flush / attribute domain (not the case here).  I'll
soon push workqueue document upstream and also am preparing more
helpers (alloc_ordered_workqueue() and flush_work_sync()) and
conversions of various users for the next cycle.  Hopefully, what to
use when will get clearer with those.

Thank you for doing this.

-- 
tejun