[Intel-gfx] [PATCH 04/40] drm/i915: Check for no-op priority changes first

[Tvrtko Ursulin]

On 08/05/2019 09:06, Chris Wilson wrote:
> In all likelihood, the priority and node are already in the CPU cache
> and by checking them first, we can avoid having to chase the
> *request->hwsp for the current breadcrumb.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_scheduler.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
> index f32d0ee6d58c..5581c5004ff0 100644
> --- a/drivers/gpu/drm/i915/i915_scheduler.c
> +++ b/drivers/gpu/drm/i915/i915_scheduler.c
> @@ -200,10 +200,10 @@ static void __i915_schedule(struct i915_sched_node *node,
>   	lockdep_assert_held(&schedule_lock);
>   	GEM_BUG_ON(prio == I915_PRIORITY_INVALID);
>   
> -	if (node_signaled(node))
> +	if (prio <= READ_ONCE(node->attr.priority))
>   		return;
>   
> -	if (prio <= READ_ONCE(node->attr.priority))
> +	if (node_signaled(node))
>   		return;
>   
>   	stack.signaler = node;
> 

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko