Re: [PATCH] [media] pvrusb2: Remove deprecated create_singlethread_workqueue

[Tejun Heo]

On Sat, Jul 16, 2016 at 02:02:34PM +0530, Bhaktipriya Shridhar wrote:
> The workqueue "workqueue" is involved in polling the pvrusb2 hardware
> (pvr2_hdw).
> 
> It has a single work item(&hdw->workpoll) and hence doesn't require
> ordering. Also, it is not being used on a memory reclaim path.
> Hence, the singlethreaded workqueue has been replaced with the use of
> system_wq.
> 
> System workqueues have been able to handle high level of concurrency
> for a long time now and hence it's not required to have a singlethreaded
> workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue
> created with create_singlethread_workqueue(), system_wq allows multiple
> work items to overlap executions even on the same CPU; however, a
> per-cpu workqueue doesn't have any CPU locality or global ordering
> guarantee unless the target CPU is explicitly specified and thus the
> increase of local concurrency shouldn't make any difference.
> 
> Work item has been flushed in pvr2_hdw_destroy to ensure that there are no
> pending tasks while disconnecting the driver.
> 
> Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@xxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks.

-- 
tejun