[PATCH v6 4/7] drm/sched: cleanup gpu_scheduler trace events

[Steven Rostedt]

On Thu, 14 Nov 2024 11:01:07 +0100
Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer at amd.com> wrote:

> A fence uniquely identify a job, so this commits updates the places
> where a kernel pointer was used as an identifier by:
> 
>    "fence=(context:%llu, seqno:%lld)"
> 
> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer at amd.com>
> ---
>  .../gpu/drm/scheduler/gpu_scheduler_trace.h   | 39 +++++++++++--------
>  1 file changed, 22 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h b/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
> index c4ec28540656..24358c4d5bbe 100644
> --- a/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
> +++ b/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
> @@ -36,28 +36,29 @@ DECLARE_EVENT_CLASS(drm_sched_job,
>  	    TP_PROTO(struct drm_sched_job *sched_job, struct drm_sched_entity *entity),
>  	    TP_ARGS(sched_job, entity),
>  	    TP_STRUCT__entry(
> -			     __field(struct drm_sched_entity *, entity)
> -			     __field(struct dma_fence *, fence)
>  			     __string(name, sched_job->sched->name)

The __string() is a 4 byte meta field in the trace event structure. This
means if you have a 64bit (8 byte) field following it, there will likely be
a 4 byte hole between the two fields.

I would suggest swapping the name field with the id field, then you will
have four 4 byte fields in a row (name, job_count, hw_job_count, dev),
which should fill all the holes.

-- Steve


>  			     __field(uint64_t, id)
>  			     __field(u32, job_count)
>  			     __field(int, hw_job_count)
>  			     __string(dev, dev_name(sched_job->sched->dev))
> +			     __field(uint64_t, fence_context)
> +			     __field(uint64_t, fence_seqno)
>  			     ),
>  
>  	    TP_fast_assign(
> -			   __entry->entity = entity;
>  			   __entry->id = sched_job->id;
> -			   __entry->fence = &sched_job->s_fence->finished;
>  			   __assign_str(name);
>  			   __entry->job_count = spsc_queue_count(&entity->job_queue);
>  			   __entry->hw_job_count = atomic_read(
>  				   &sched_job->sched->credit_count);
>  			   __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, entity=%p, id=%llu, fence=%p, ring=%s, job count:%u, hw job count:%d",
> -		      __get_str(dev), __entry->entity, __entry->id,
> -		      __entry->fence, __get_str(name),
> +	    TP_printk("dev=%s, id=%llu, fence=(context:%llu, seqno:%lld), ring=%s, job count:%u, hw job count:%d",
> +		      __get_str(dev), __entry->id,
> +		      __entry->fence_context, __entry->fence_seqno, __get_str(name),
>  		      __entry->job_count, __entry->hw_job_count)
>  );
>