[Intel-gfx] [PATCH 10/11] drm/i915/execlists: Skip direct submission if only lite-restore

[Tvrtko Ursulin]

On 26/02/2019 10:24, Chris Wilson wrote:
> If we resubmitting the active context, simply skip the submission as

we are

> performing the submission from the interrupt handler has higher

 From the tasklet? You mean wait for ctx complete and then 
execlists_dequeue, instead of lite-restore?

Regards,

Tvrtko

> throughput than continually provoking lite-restores. If however, we find
> ourselves with a new client, we check whether or not we can dequeue into
> the second port or to resolve preemption.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/intel_lrc.c | 24 +++++++++++++++++++-----
>   1 file changed, 19 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 2268860cca44..3e9f7103f31f 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -1205,12 +1205,26 @@ static void __submit_queue_imm(struct intel_engine_cs *engine)
>   		tasklet_hi_schedule(&execlists->tasklet);
>   }
>   
> -static void submit_queue(struct intel_engine_cs *engine, int prio)
> +static bool inflight(const struct intel_engine_execlists *execlists,
> +		     const struct i915_request *rq)
>   {
> -	if (prio > engine->execlists.queue_priority_hint) {
> -		engine->execlists.queue_priority_hint = prio;
> +	const struct i915_request *active = port_request(execlists->port);
> +
> +	return active && active->hw_context == rq->hw_context;
> +}
> +
> +static void submit_queue(struct intel_engine_cs *engine,
> +			 const struct i915_request *rq)
> +{
> +	struct intel_engine_execlists *execlists = &engine->execlists;
> +
> +	if (rq_prio(rq) <= execlists->queue_priority_hint)
> +		return;
> +
> +	execlists->queue_priority_hint = rq_prio(rq);
> +
> +	if (!inflight(execlists, rq))
>   		__submit_queue_imm(engine);
> -	}
>   }
>   
>   static void execlists_submit_request(struct i915_request *request)
> @@ -1226,7 +1240,7 @@ static void execlists_submit_request(struct i915_request *request)
>   	GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root));
>   	GEM_BUG_ON(list_empty(&request->sched.link));
>   
> -	submit_queue(engine, rq_prio(request));
> +	submit_queue(engine, request);
>   
>   	spin_unlock_irqrestore(&engine->timeline.lock, flags);
>   }
>