[Intel-gfx] [PATCH 1/4] drm/i915/gt: Always reset the timeslice after a context switch

[Tvrtko Ursulin]

On 13/01/2020 10:44, Chris Wilson wrote:
> Currently, we reset the timer after a pre-eemption event. This has the
> side-effect that the timeslice runs into the second context after the
> first is completed. To be more fair, we want to reset the clock after
> promotion as well.

You mean after completion? If so then it makes sense to me.
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   drivers/gpu/drm/i915/gt/intel_lrc.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index 9af1b2b493f4..a6ac37dece0a 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -2285,7 +2285,6 @@ static void process_csb(struct intel_engine_cs *engine)
>   
>   			/* Point active to the new ELSP; prevent overwriting */
>   			WRITE_ONCE(execlists->active, execlists->pending);
> -			set_timeslice(engine);
>   
>   			if (!inject_preempt_hang(execlists))
>   				ring_set_paused(engine, 0);
> @@ -2325,6 +2324,9 @@ static void process_csb(struct intel_engine_cs *engine)
>   		}
>   	} while (head != tail);
>   
> +	if (execlists_active(execlists))
> +		set_timeslice(engine);
> +
>   	execlists->csb_head = head;
>   
>   	/*
> 

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

Regards,

Tvrtko