Re: [PATCH] ps3: Remove deprecated create_singlethread_workqueue

From: Tejun Heo
Date: Wed Aug 31 2016 - 10:23:55 EST


On Tue, Aug 30, 2016 at 10:44:51PM +0530, Bhaktipriya Shridhar wrote:
> The workqueue "ps3av->wq" queues a single work item &ps3av->work and hence
> doesn't require ordering. It is involved in waking up ps3avd to do the
> video mode setting and hence it's not being used on a memory reclaim
> path. Hence, it has been converted to use 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.
>
> The work item has been flushed in ps3av_remove 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