Re: [PATCH v8 05/10] drm/sched: trace dependencies for gpu jobs

[Tvrtko Ursulin <tursulin@ursulin.net>]

On 20/03/2025 09:58, Pierre-Eric Pelloux-Prayer wrote:
> We can't trace dependencies from drm_sched_job_add_dependency
> because when it's called the job's fence is not available yet.
> 
> So instead each dependency is traced individually when
> drm_sched_entity_push_job is used.
> 
> Tracing the dependencies allows tools to analyze the dependencies
> between the jobs (previously it was only possible for fences
> traced by drm_sched_job_wait_dep).
> 
> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
> ---
>   .../gpu/drm/scheduler/gpu_scheduler_trace.h   | 24 ++++++++++++++++++-
>   drivers/gpu/drm/scheduler/sched_entity.c      |  8 +++++++
>   2 files changed, 31 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h b/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
> index 21a85ee59066..5d9992ad47d3 100644
> --- a/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
> +++ b/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
> @@ -54,7 +54,6 @@ DECLARE_EVENT_CLASS(drm_sched_job,
>   			   __assign_str(dev);
>   			   __entry->fence_context = sched_job->s_fence->finished.context;
>   			   __entry->fence_seqno = sched_job->s_fence->finished.seqno;
> -
>   			   ),
>   	    TP_printk("dev=%s, id=%llu, fence=%llu:%llu, ring=%s, job count:%u, hw job count:%d",
>   		      __get_str(dev), __entry->id,
> @@ -88,6 +87,29 @@ TRACE_EVENT(drm_sched_process_job,
>   		      __entry->fence_context, __entry->fence_seqno)
>   );
>   
> +TRACE_EVENT(drm_sched_job_add_dep,
> +	TP_PROTO(struct drm_sched_job *sched_job, struct dma_fence *fence),
> +	TP_ARGS(sched_job, fence),
> +	TP_STRUCT__entry(
> +		    __field(u64, fence_context)
> +		    __field(u64, fence_seqno)
> +		    __field(u64, id)
> +		    __field(u64, ctx)
> +		    __field(u64, seqno)
> +		    ),
> +
> +	TP_fast_assign(
> +		    __entry->fence_context = sched_job->s_fence->finished.context;
> +		    __entry->fence_seqno = sched_job->s_fence->finished.seqno;
> +		    __entry->id = sched_job->id;
> +		    __entry->ctx = fence->context;
> +		    __entry->seqno = fence->seqno;
> +		    ),
> +	TP_printk("fence=%llu:%llu, id=%llu depends on fence=%llu:%llu",
> +		  __entry->fence_context, __entry->fence_seqno, __entry->id,
> +		  __entry->ctx, __entry->seqno)
> +);
> +
>   TRACE_EVENT(drm_sched_job_wait_dep,
>   	    TP_PROTO(struct drm_sched_job *sched_job, struct dma_fence *fence),
>   	    TP_ARGS(sched_job, fence),
> diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
> index a6d2a4722d82..047e42cfb129 100644
> --- a/drivers/gpu/drm/scheduler/sched_entity.c
> +++ b/drivers/gpu/drm/scheduler/sched_entity.c
> @@ -580,6 +580,14 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
>   	ktime_t submit_ts;
>   
>   	trace_drm_sched_job(sched_job, entity);
> +
> +	if (trace_drm_sched_job_add_dep_enabled()) {
> +		struct dma_fence *entry;
> +		unsigned long index;
> +
> +		xa_for_each(&sched_job->dependencies, index, entry)
> +			trace_drm_sched_job_add_dep(sched_job, entry);
> +	}
>   	atomic_inc(entity->rq->sched->score);
>   	WRITE_ONCE(entity->last_user, current->group_leader);
>   

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>

Regards,

Tvrtko