Re: [PATCH 18/27] drm/i915/guc: Update debugfs for GuC multi-lrc

[John Harrison <john.c.harrison@xxxxxxxxx>]

On 8/20/2021 15:44, Matthew Brost wrote:
> Display the workqueue status in debugfs for GuC contexts that are in
> parent-child relationship.
>
> Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
> ---
>   .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 51 ++++++++++++++-----
>   1 file changed, 37 insertions(+), 14 deletions(-)
>
> 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 e34e0ea9136a..07eee9a399c8 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -3673,6 +3673,26 @@ static void guc_log_context_priority(struct drm_printer *p,
>   	drm_printf(p, "\n");
>   }
>   
> +
> +static inline void guc_log_context(struct drm_printer *p,
> +				   struct intel_context *ce)
> +{
> +	drm_printf(p, "GuC lrc descriptor %u:\n", ce->guc_id.id);
> +	drm_printf(p, "\tHW Context Desc: 0x%08x\n", ce->lrc.lrca);
> +	drm_printf(p, "\t\tLRC Head: Internal %u, Memory %u\n",
> +		   ce->ring->head,
> +		   ce->lrc_reg_state[CTX_RING_HEAD]);
> +	drm_printf(p, "\t\tLRC Tail: Internal %u, Memory %u\n",
> +		   ce->ring->tail,
> +		   ce->lrc_reg_state[CTX_RING_TAIL]);
> +	drm_printf(p, "\t\tContext Pin Count: %u\n",
> +		   atomic_read(&ce->pin_count));
> +	drm_printf(p, "\t\tGuC ID Ref Count: %u\n",
> +		   atomic_read(&ce->guc_id.ref));
> +	drm_printf(p, "\t\tSchedule State: 0x%x\n\n",
> +		   ce->guc_state.sched_state);
> +}
> +
>   void intel_guc_submission_print_context_info(struct intel_guc *guc,
>   					     struct drm_printer *p)
>   {
> @@ -3682,22 +3702,25 @@ void intel_guc_submission_print_context_info(struct intel_guc *guc,
>   
>   	xa_lock_irqsave(&guc->context_lookup, flags);
>   	xa_for_each(&guc->context_lookup, index, ce) {
> -		drm_printf(p, "GuC lrc descriptor %u:\n", ce->guc_id.id);
> -		drm_printf(p, "\tHW Context Desc: 0x%08x\n", ce->lrc.lrca);
> -		drm_printf(p, "\t\tLRC Head: Internal %u, Memory %u\n",
> -			   ce->ring->head,
> -			   ce->lrc_reg_state[CTX_RING_HEAD]);
> -		drm_printf(p, "\t\tLRC Tail: Internal %u, Memory %u\n",
> -			   ce->ring->tail,
> -			   ce->lrc_reg_state[CTX_RING_TAIL]);
> -		drm_printf(p, "\t\tContext Pin Count: %u\n",
> -			   atomic_read(&ce->pin_count));
> -		drm_printf(p, "\t\tGuC ID Ref Count: %u\n",
> -			   atomic_read(&ce->guc_id.ref));
> -		drm_printf(p, "\t\tSchedule State: 0x%x\n\n",
> -			   ce->guc_state.sched_state);
> +		GEM_BUG_ON(intel_context_is_child(ce));
>   
> +		guc_log_context(p, ce);
>   		guc_log_context_priority(p, ce);
> +
> +		if (intel_context_is_parent(ce)) {
> +			struct guc_process_desc *desc = __get_process_desc(ce);
> +			struct intel_context *child;
> +
> +			drm_printf(p, "\t\tWQI Head: %u\n",
> +				   READ_ONCE(desc->head));
> +			drm_printf(p, "\t\tWQI Tail: %u\n",
> +				   READ_ONCE(desc->tail));
> +			drm_printf(p, "\t\tWQI Status: %u\n\n",
> +				   READ_ONCE(desc->wq_status));
> +
> +			for_each_child(ce, child)
> +				guc_log_context(p, child);
There should be some indication that this is a child context and/or how 
many children there are. Otherwise how does the reader differentiation 
between the list of child contexts and the next parent/single context?

John.

> +		}
>   	}
>   	xa_unlock_irqrestore(&guc->context_lookup, flags);
>   }