Commit 70102d77 authored by Christian König's avatar Christian König
Browse files

drm/scheduler: add drm_sched_entity_error and use rcu for last_scheduled 



Switch to using RCU handling for the last scheduled job and add a
function to return the error code of it.

Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarLuben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230420115752.31470-2-christian.koenig@amd.com
parent 539f9ee4

drivers/gpu/drm/scheduler/sched_entity.c

+31 −8
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, 
	entity->num_sched_list = num_sched_list;

	entity->priority = priority;

	entity->sched_list = num_sched_list > 1 ? sched_list : NULL;

	entity->last_scheduled = NULL;

	RCU_INIT_POINTER(entity->last_scheduled, NULL);

	RB_CLEAR_NODE(&entity->rb_tree_node);



	if(num_sched_list)
@@ -140,6 +140,27 @@ bool drm_sched_entity_is_ready(struct drm_sched_entity *entity) 
	return true;

}



/**

 * drm_sched_entity_error - return error of last scheduled job

 * @entity: scheduler entity to check

 *

 * Opportunistically return the error of the last scheduled job. Result can

 * change any time when new jobs are pushed to the hw.

 */

int drm_sched_entity_error(struct drm_sched_entity *entity)

{

	struct dma_fence *fence;

	int r;



	rcu_read_lock();

	fence = rcu_dereference(entity->last_scheduled);

	r = fence ? fence->error : 0;

	rcu_read_unlock();



	return r;

}

EXPORT_SYMBOL(drm_sched_entity_error);



static void drm_sched_entity_kill_jobs_work(struct work_struct *wrk)

{

	struct drm_sched_job *job = container_of(wrk, typeof(*job), work);
@@ -191,7 +212,9 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity) 
	/* Make sure this entity is not used by the scheduler at the moment */

	wait_for_completion(&entity->entity_idle);



	prev = dma_fence_get(entity->last_scheduled);

	/* The entity is guaranteed to not be used by the scheduler */

	prev = rcu_dereference_check(entity->last_scheduled, true);

	dma_fence_get(prev);

	while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {

		struct drm_sched_fence *s_fence = job->s_fence;
@@ -278,8 +301,8 @@ void drm_sched_entity_fini(struct drm_sched_entity *entity) 
		entity->dependency = NULL;

	}



	dma_fence_put(entity->last_scheduled);

	entity->last_scheduled = NULL;

	dma_fence_put(rcu_dereference_check(entity->last_scheduled, true));

	RCU_INIT_POINTER(entity->last_scheduled, NULL);

}

EXPORT_SYMBOL(drm_sched_entity_fini);
@@ -421,9 +444,9 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) 
	if (entity->guilty && atomic_read(entity->guilty))

		dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED);



	dma_fence_put(entity->last_scheduled);



	entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished);

	dma_fence_put(rcu_dereference_check(entity->last_scheduled, true));

	rcu_assign_pointer(entity->last_scheduled,

			   dma_fence_get(&sched_job->s_fence->finished));



	/*

	 * If the queue is empty we allow drm_sched_entity_select_rq() to
@@ -477,7 +500,7 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) 
	 */

	smp_rmb();



	fence = entity->last_scheduled;

	fence = rcu_dereference_check(entity->last_scheduled, true);



	/* stay on the same engine if the previous job hasn't finished */

	if (fence && !dma_fence_is_signaled(fence))

include/drm/gpu_scheduler.h

+2 −1
Original line number Diff line number Diff line
@@ -201,7 +201,7 @@ struct drm_sched_entity { 
	 * by the scheduler thread, can be accessed locklessly from

	 * drm_sched_job_arm() iff the queue is empty.

	 */

	struct dma_fence                *last_scheduled;

	struct dma_fence __rcu		*last_scheduled;



	/**

	 * @last_user: last group leader pushing a job into the entity.
@@ -588,6 +588,7 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job); 
void drm_sched_entity_set_priority(struct drm_sched_entity *entity,

				   enum drm_sched_priority priority);

bool drm_sched_entity_is_ready(struct drm_sched_entity *entity);

int drm_sched_entity_error(struct drm_sched_entity *entity);



void drm_sched_fence_set_parent(struct drm_sched_fence *s_fence,

				struct dma_fence *fence);