Re: [PATCH] fbdev: Remove deprecated create_singlethread_workqueue

From: Tejun Heo
Date: Sat Jul 02 2016 - 07:36:42 EST


On Sat, Jul 02, 2016 at 02:09:23PM +0530, Bhaktipriya Shridhar wrote:
> The workqueue "esd_wq" has only a single workitem(&md->esd_work)
> 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.
>
> mipid_esd_stop_check () calls cancel_delayed_work() in mipid_cleanup()
> 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