[RFC v4 10/16] drm/sched: Free all finished jobs at once

[Tvrtko Ursulin]

On 12/05/2025 13:56, Philipp Stanner wrote:
> On Fri, 2025-04-25 at 11:20 +0100, Tvrtko Ursulin wrote:
>> To implement fair scheduling we will need as accurate as possible
>> view
>> into per entity GPU time utilisation. Because sched fence execution
>> time
>> are only adjusted for accuracy in the free worker we need to process
>> completed jobs as soon as possible so the metric is most up to date
>> when
>> view from the submission side of things.
>>
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
>> Cc: Christian König <christian.koenig at amd.com>
>> Cc: Danilo Krummrich <dakr at kernel.org>
>> Cc: Matthew Brost <matthew.brost at intel.com>
>> Cc: Philipp Stanner <phasta at kernel.org>
>> ---
>>   drivers/gpu/drm/scheduler/sched_main.c | 15 ++-------------
>>   1 file changed, 2 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/scheduler/sched_main.c
>> b/drivers/gpu/drm/scheduler/sched_main.c
>> index 8950c7705f57..22428a1569dd 100644
>> --- a/drivers/gpu/drm/scheduler/sched_main.c
>> +++ b/drivers/gpu/drm/scheduler/sched_main.c
>> @@ -865,13 +865,12 @@ drm_sched_select_entity(struct
>> drm_gpu_scheduler *sched)
>>    * drm_sched_get_finished_job - fetch the next finished job to be
>> destroyed
>>    *
>>    * @sched: scheduler instance
>> - * @have_more: are there more finished jobs on the list
>>    *
>>    * Returns the next finished job from the pending list (if there is
>> one)
>>    * ready for it to be destroyed.
>>    */
>>   static struct drm_sched_job *
>> -drm_sched_get_finished_job(struct drm_gpu_scheduler *sched, bool
>> *have_more)
>> +drm_sched_get_finished_job(struct drm_gpu_scheduler *sched)
>>   {
>>   	struct drm_sched_job *job, *next;
>>   
>> @@ -886,7 +885,6 @@ drm_sched_get_finished_job(struct
>> drm_gpu_scheduler *sched, bool *have_more)
>>   		/* cancel this job's TO timer */
>>   		cancel_delayed_work(&sched->work_tdr);
>>   
>> -		*have_more = false;
>>   		next = list_first_entry_or_null(&sched-
>>> pending_list,
>>   						typeof(*next),
>> list);
>>   		if (next) {
>> @@ -896,10 +894,6 @@ drm_sched_get_finished_job(struct
>> drm_gpu_scheduler *sched, bool *have_more)
>>   				next->s_fence->scheduled.timestamp =
>>   					dma_fence_timestamp(&job-
>>> s_fence->finished);
>>   
>> -			if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
>> -				     &next->s_fence-
>>> finished.flags))
>> -				*have_more = true;
>> -
>>   			/* start TO timer for next job */
>>   			drm_sched_start_timeout(sched);
>>   		}
>> @@ -958,14 +952,9 @@ static void drm_sched_free_job_work(struct
>> work_struct *w)
>>   	struct drm_gpu_scheduler *sched =
>>   		container_of(w, struct drm_gpu_scheduler,
>> work_free_job);
>>   	struct drm_sched_job *job;
>> -	bool have_more;
>>   
>> -	job = drm_sched_get_finished_job(sched, &have_more);
>> -	if (job) {
>> +	while ((job = drm_sched_get_finished_job(sched)))
>>   		sched->ops->free_job(job);
>> -		if (have_more)
>> -			__drm_sched_run_free_queue(sched);
>> -	}
> 
> Are there any have_more users left after that?
> 
> Removing here what was added before IMO makes it more questionable
> adding that improvement in the first place.

Yep, it is definitely not typical to add and then remove stuff in the 
same series. Reason is series was not intended (or expected) to get 
accepted as one. I was expecting easy cleanups to get in fast and the 
rest to keep iterating for who knows how long.

Regards,

Tvrtko