[PATCH 2/3] drm/atomic: Use kthread worker for nonblocking commits

[Hillf Danton]

Sat, 19 Sep 2020 12:37:25 -0700 Rob Clark wrote:
>  
> @@ -1797,6 +1797,7 @@ int drm_atomic_helper_commit(struct drm_device *dev,
>  			     struct drm_atomic_state *state,
>  			     bool nonblock)
>  {
> +	struct kthread_worker *worker = NULL;
>  	int ret;
>  
>  	if (state->async_update) {
> @@ -1814,7 +1815,7 @@ int drm_atomic_helper_commit(struct drm_device *dev,
>  	if (ret)
>  		return ret;
>  
> -	INIT_WORK(&state->commit_work, commit_work);
> +	kthread_init_work(&state->commit_kwork, commit_work);
>  
>  	ret = drm_atomic_helper_prepare_planes(dev, state);
>  	if (ret)
> @@ -1857,8 +1858,12 @@ int drm_atomic_helper_commit(struct drm_device *dev,
>  	 */
>  
>  	drm_atomic_state_get(state);
> +
>  	if (nonblock)
> -		queue_work(system_unbound_wq, &state->commit_work);
> +		worker = drm_atomic_pick_worker(state);
> +
> +	if (worker)
> +		kthread_queue_work(worker, &state->commit_kwork);
>  	else
>  		commit_tail(state);

A minor change in behavior: commit_tail() would have nothing to do with
either worker or work, rather than the fallback in case no worker is
available.