[Intel-gfx] [CI 04/20] drm/i915: Remove the dedicated hangcheck workqueue

[Tvrtko Ursulin]

On 19/05/16 12:32, Chris Wilson wrote:
> The queue only ever contains at most one item and has no special flags.
> It is just a very simple wrapper around the system-wq - a complication
> with no benefits.

How much time do we take in the reset case - is it acceptable to do that 
work from the system wq?

Hm, why was it an ordered queue so far - we only queue single work on it?

Regards,

Tvrtko

> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/i915_dma.c | 8 --------
>   drivers/gpu/drm/i915/i915_drv.h | 1 -
>   drivers/gpu/drm/i915/i915_irq.c | 6 +++---
>   3 files changed, 3 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> index a8c79f6512a4..aa312fd2bc10 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -1026,15 +1026,8 @@ static int i915_workqueues_init(struct drm_i915_private *dev_priv)
>   	if (dev_priv->hotplug.dp_wq == NULL)
>   		goto out_free_wq;
>
> -	dev_priv->gpu_error.hangcheck_wq =
> -		alloc_ordered_workqueue("i915-hangcheck", 0);
> -	if (dev_priv->gpu_error.hangcheck_wq == NULL)
> -		goto out_free_dp_wq;
> -
>   	return 0;
>
> -out_free_dp_wq:
> -	destroy_workqueue(dev_priv->hotplug.dp_wq);
>   out_free_wq:
>   	destroy_workqueue(dev_priv->wq);
>   out_err:
> @@ -1045,7 +1038,6 @@ out_err:
>
>   static void i915_workqueues_cleanup(struct drm_i915_private *dev_priv)
>   {
> -	destroy_workqueue(dev_priv->gpu_error.hangcheck_wq);
>   	destroy_workqueue(dev_priv->hotplug.dp_wq);
>   	destroy_workqueue(dev_priv->wq);
>   }
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 72f0b02a8372..42b8038bf998 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1366,7 +1366,6 @@ struct i915_gpu_error {
>   	/* Hang gpu twice in this window and your context gets banned */
>   #define DRM_I915_CTX_BAN_PERIOD DIV_ROUND_UP(8*DRM_I915_HANGCHECK_PERIOD, 1000)
>
> -	struct workqueue_struct *hangcheck_wq;
>   	struct delayed_work hangcheck_work;
>
>   	/* For reset and error_state handling. */
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 4818fcb5e960..984b575ba081 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3262,7 +3262,7 @@ out:
>
>   void i915_queue_hangcheck(struct drm_i915_private *dev_priv)
>   {
> -	struct i915_gpu_error *e = &dev_priv->gpu_error;
> +	unsigned long delay;
>
>   	if (!i915.enable_hangcheck)
>   		return;
> @@ -3272,8 +3272,8 @@ void i915_queue_hangcheck(struct drm_i915_private *dev_priv)
>   	 * we will ignore a hung ring if a second ring is kept busy.
>   	 */
>
> -	queue_delayed_work(e->hangcheck_wq, &e->hangcheck_work,
> -			   round_jiffies_up_relative(DRM_I915_HANGCHECK_JIFFIES));
> +	delay = round_jiffies_up_relative(DRM_I915_HANGCHECK_JIFFIES);
> +	schedule_delayed_work(&dev_priv->gpu_error.hangcheck_work, delay);
>   }
>
>   static void ibx_irq_reset(struct drm_device *dev)
>