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

["Christian König" <christian.koenig@amd.com>]

Am 02.02.24 um 22:58 schrieb 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?!

No, this comes from Matthews work on the DRM scheduler.

Matthews patches were most likely merged through drm-misc.

Regards,
Christian.

>
>>> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
>> Reviewed-by: Christian König <christian.koenig@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);