Re: [PATCH 3/3] i915/guc: Accumulate active runtime on gt reset

[John Harrison <john.c.harrison@intel.com>]

On 11/27/2024 09:40, Umesh Nerlige Ramappa wrote:
> On gt reset, if a context is running, then accumulate it's active time
> into the busyness counter since there will be no chance for the context
> to switch out and update it's run time.
>
> v2: Move comment right above the if (John)
>
> Fixes: 77cdd054dd2c ("drm/i915/pmu: Connect engine busyness stats from GuC to pmu")
> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>

> ---
>   drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 15 ++++++++++++++-
>   1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> index 56be9f385270..2876024041a7 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -1449,8 +1449,21 @@ static void __reset_guc_busyness_stats(struct intel_guc *guc)
>   
>   	guc_update_pm_timestamp(guc, &unused);
>   	for_each_engine(engine, gt, id) {
> +		struct intel_engine_guc_stats *stats = &engine->stats.guc;
> +
>   		guc_update_engine_gt_clks(engine);
> -		engine->stats.guc.prev_total = 0;
> +
> +		/*
> +		 * If resetting a running context, accumulate the active
> +		 * time as well since there will be no context switch.
> +		 */
> +		if (stats->running) {
> +			u64 clk = guc->timestamp.gt_stamp - stats->start_gt_clk;
> +
> +			stats->total_gt_clks += clk;
> +		}
> +		stats->prev_total = 0;
> +		stats->running = 0;
>   	}
>   
>   	spin_unlock_irqrestore(&guc->timestamp.lock, flags);