[Intel-gfx] [PATCH 1/5] drm/i915: Mark semaphores as complete on unsubmit out if payload was started

[Tvrtko Ursulin]

On 15/05/2019 14:00, Chris Wilson wrote:
> Avoid charging us for the presumed busywait if the request was preempted
> after successfully using semaphores to reduce inter-engine latency.
> 
> v2: Bump the priority to reflect the lack of semaphores now required.
> 
> References: ca6e56f654e7 ("drm/i915: Disable semaphore busywaits on saturated systems")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_request.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
> index bed213148cbb..11670774cd25 100644
> --- a/drivers/gpu/drm/i915/i915_request.c
> +++ b/drivers/gpu/drm/i915/i915_request.c
> @@ -509,6 +509,12 @@ void __i915_request_unsubmit(struct i915_request *request)
>   	/* Transfer back from the global per-engine timeline to per-context */
>   	move_to_timeline(request, request->timeline);
>   
> +	/* We've already spun, don't charge on resubmitting. */
> +	if (request->sched.semaphores && i915_request_started(request)) {
> +		request->sched.attr.priority |= I915_PRIORITY_NOSEMAPHORE;
> +		request->sched.semaphores = 0;
> +	}
> +
>   	/*
>   	 * We don't need to wake_up any waiters on request->execute, they
>   	 * will get woken by any other event or us re-adding this request
> 

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

Regards,

Tvrtko