[Intel-gfx] [PATCH] drm/i915/execlists: Hesitate before slicing

[Lionel Landwerlin]

On 27/06/2019 17:23, Chris Wilson wrote:
> Be a little more hesitant before injecting a timeslice, and try to take
> into account any change in priority that is due for the running task
> before switching to another task. This will allow us to arbitrarily
> prevent switching away from a request if we deem it necessarily to
> disable preemption, for instance.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>


Description sounds like what I'm looking for for perf queries with 
global counters.


Acked-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>


> ---
>   drivers/gpu/drm/i915/gt/intel_lrc.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index 471e134de186..9bbab7963951 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -899,7 +899,7 @@ need_timeslice(struct intel_engine_cs *engine, const struct i915_request *rq)
>   	hint = max(rq_prio(list_next_entry(rq, sched.link)),
>   		   engine->execlists.queue_priority_hint);
>   
> -	return hint >= rq_prio(rq);
> +	return hint >= effective_prio(rq);
>   }
>   
>   static bool