[Intel-gfx] [PATCH 01/11] drm/i915: Skip scanning for signalers if we are already inflight

[Tvrtko Ursulin]

On 26/02/2019 10:23, Chris Wilson wrote:
> When a request has its priority changed, we traverse the graph of all of
> its signalers to raise their priorities to match (priority inheritance).
> If the request has already started executing its payload, we know that
> all of its signalers must have signaled and we do not need to process
> our list of signalers.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/i915_scheduler.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
> index 8bc042551692..38efefd22dce 100644
> --- a/drivers/gpu/drm/i915/i915_scheduler.c
> +++ b/drivers/gpu/drm/i915/i915_scheduler.c
> @@ -18,6 +18,11 @@ node_to_request(const struct i915_sched_node *node)
>   	return container_of(node, const struct i915_request, sched);
>   }
>   
> +static inline bool node_started(const struct i915_sched_node *node)
> +{
> +	return i915_request_started(node_to_request(node));
> +}
> +
>   static inline bool node_signaled(const struct i915_sched_node *node)
>   {
>   	return i915_request_completed(node_to_request(node));
> @@ -301,6 +306,10 @@ static void __i915_schedule(struct i915_request *rq,
>   	list_for_each_entry(dep, &dfs, dfs_link) {
>   		struct i915_sched_node *node = dep->signaler;
>   
> +		/* If we are already flying, we know we have no signalers */
> +		if (node_started(node))
> +			continue;
> +
>   		/*
>   		 * Within an engine, there can be no cycle, but we may
>   		 * refer to the same dependency chain multiple times
> 

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

Regards,

Tvrtko