[PATCH] drm/sched: Re-queue run job worker when drm_sched_entity_pop_job() returns NULL

[Rodrigo Vivi]

On Tue, Jan 30, 2024 at 08:05:29AM +0100, Christian König wrote:
> Am 30.01.24 um 04:04 schrieb Matthew Brost:
> > Rather then loop over entities until one with a ready job is found,
> > re-queue the run job worker when drm_sched_entity_pop_job() returns NULL.
> > 
> > Fixes: 6dbd9004a55 ("drm/sched: Drain all entities in DRM sched run job worker")

First of all there's a small typo in this Fixes tag that needs to be fixed.
The correct one is:

Fixes: 66dbd9004a55 ("drm/sched: Drain all entities in DRM sched run job worker")

But I couldn't apply this right now in any of our drm-tip trees because it
is not clear where this is coming from originally.

likely amd tree?!

> > Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> 
> Reviewed-by: Christian König <christian.koenig at amd.com>

Christian, if this came from the amd, could you please apply it there and
propagate through your fixes flow?

Thanks,
Rodrigo.

> 
> > ---
> >   drivers/gpu/drm/scheduler/sched_main.c | 15 +++++++++------
> >   1 file changed, 9 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> > index 8acbef7ae53d..7e90c9f95611 100644
> > --- a/drivers/gpu/drm/scheduler/sched_main.c
> > +++ b/drivers/gpu/drm/scheduler/sched_main.c
> > @@ -1178,21 +1178,24 @@ static void drm_sched_run_job_work(struct work_struct *w)
> >   	struct drm_sched_entity *entity;
> >   	struct dma_fence *fence;
> >   	struct drm_sched_fence *s_fence;
> > -	struct drm_sched_job *sched_job = NULL;
> > +	struct drm_sched_job *sched_job;
> >   	int r;
> >   	if (READ_ONCE(sched->pause_submit))
> >   		return;
> >   	/* Find entity with a ready job */
> > -	while (!sched_job && (entity = drm_sched_select_entity(sched))) {
> > -		sched_job = drm_sched_entity_pop_job(entity);
> > -		if (!sched_job)
> > -			complete_all(&entity->entity_idle);
> > -	}
> > +	entity = drm_sched_select_entity(sched);
> >   	if (!entity)
> >   		return;	/* No more work */
> > +	sched_job = drm_sched_entity_pop_job(entity);
> > +	if (!sched_job) {
> > +		complete_all(&entity->entity_idle);
> > +		drm_sched_run_job_queue(sched);
> > +		return;
> > +	}
> > +
> >   	s_fence = sched_job->s_fence;
> >   	atomic_add(sched_job->credits, &sched->credit_count);
>