[PATCH 1/2] drm/scheduler: Add job dependency trace.

[Christian König]

Am 31.07.2018 um 16:56 schrieb Andrey Grodzovsky:
> During debug sessions I encountered a need to trace
> back a job dependecy a few steps back to the first failing
> job. This trace helpped me a lot.
>
> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>

Reviewed-by: Christian König <christian.koenig at amd.com> for the series.

> ---
>   drivers/gpu/drm/scheduler/gpu_scheduler.c       |  8 ++++++--
>   drivers/gpu/drm/scheduler/gpu_scheduler_trace.h | 24 ++++++++++++++++++++++++
>   2 files changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler.c b/drivers/gpu/drm/scheduler/gpu_scheduler.c
> index 3f2fc5e..45703b9 100644
> --- a/drivers/gpu/drm/scheduler/gpu_scheduler.c
> +++ b/drivers/gpu/drm/scheduler/gpu_scheduler.c
> @@ -506,9 +506,13 @@ drm_sched_entity_pop_job(struct drm_sched_entity *entity)
>   	if (!sched_job)
>   		return NULL;
>   
> -	while ((entity->dependency = sched->ops->dependency(sched_job, entity)))
> -		if (drm_sched_entity_add_dependency_cb(entity))
> +	while ((entity->dependency = sched->ops->dependency(sched_job, entity))) {
> +		if (drm_sched_entity_add_dependency_cb(entity)) {
> +
> +			trace_drm_sched_job_wait_dep(sched_job, entity->dependency);
>   			return NULL;
> +		}
> +	}
>   
>   	/* skip jobs from entity that marked guilty */
>   	if (entity->guilty && atomic_read(entity->guilty))
> diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h b/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
> index 4998ad9..1626f39 100644
> --- a/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
> +++ b/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
> @@ -74,6 +74,30 @@ TRACE_EVENT(drm_sched_process_job,
>   	    TP_printk("fence=%p signaled", __entry->fence)
>   );
>   
> +TRACE_EVENT(drm_sched_job_wait_dep,
> +	    TP_PROTO(struct drm_sched_job *sched_job, struct dma_fence *fence),
> +	    TP_ARGS(sched_job, fence),
> +	    TP_STRUCT__entry(
> +			     __field(const char *,name)
> +			     __field(uint64_t, id)
> +			     __field(struct dma_fence *, fence)
> +			     __field(uint64_t, ctx)
> +			     __field(unsigned, seqno)
> +			     ),
> +
> +	    TP_fast_assign(
> +			   __entry->name = sched_job->sched->name;
> +			   __entry->id = sched_job->id;
> +			   __entry->fence = fence;
> +			   __entry->ctx = fence->context;
> +			   __entry->seqno = fence->seqno;
> +			   ),
> +	    TP_printk("job ring=%s, id=%llu, depends fence=%p, context=%llu, seq=%u",
> +		      __entry->name, __entry->id,
> +		      __entry->fence, __entry->ctx,
> +		      __entry->seqno)
> +);
> +
>   #endif
>   
>   /* This part must be outside protection */