Commit 134e71bd authored by Tvrtko Ursulin's avatar Tvrtko Ursulin Committed by Philipp Stanner
Browse files

drm/sched: Further optimise drm_sched_entity_push_job 



Having removed one re-lock cycle on the entity->lock in a patch titled
"drm/sched: Optimise drm_sched_entity_push_job", with only a tiny bit
larger refactoring we can do the same optimisation on the rq->lock.
(Currently both drm_sched_rq_add_entity() and
drm_sched_rq_update_fifo_locked() take and release the same lock.)

To achieve this we make drm_sched_rq_update_fifo_locked() and
drm_sched_rq_add_entity() expect the rq->lock to be held.

We also align drm_sched_rq_update_fifo_locked(),
drm_sched_rq_add_entity() and
drm_sched_rq_remove_fifo_locked() function signatures, by adding rq as a
parameter to the latter.

v2:
 * Fix after rebase of the series.
 * Avoid naming inconsistency between drm_sched_rq_add/remove. (Christian)

Signed-off-by: default avatarTvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Philipp Stanner <pstanner@redhat.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarPhilipp Stanner <pstanner@redhat.com>
Signed-off-by: default avatarPhilipp Stanner <pstanner@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-6-tursulin@igalia.com
parent f93126f5

drivers/gpu/drm/scheduler/sched_entity.c

+9 −2
Original line number Diff line number Diff line
@@ -515,9 +515,14 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) 


		next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));

		if (next) {

			struct drm_sched_rq *rq;



			spin_lock(&entity->lock);

			drm_sched_rq_update_fifo_locked(entity,

			rq = entity->rq;

			spin_lock(&rq->lock);

			drm_sched_rq_update_fifo_locked(entity, rq,

							next->submit_ts);

			spin_unlock(&rq->lock);

			spin_unlock(&entity->lock);

		}

	}
@@ -616,11 +621,13 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job) 
		rq = entity->rq;

		sched = rq->sched;



		spin_lock(&rq->lock);

		drm_sched_rq_add_entity(rq, entity);



		if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)

			drm_sched_rq_update_fifo_locked(entity, submit_ts);

			drm_sched_rq_update_fifo_locked(entity, rq, submit_ts);



		spin_unlock(&rq->lock);

		spin_unlock(&entity->lock);



		drm_sched_wakeup(sched);

drivers/gpu/drm/scheduler/sched_main.c

+14 −15
Original line number Diff line number Diff line
@@ -153,17 +153,18 @@ static __always_inline bool drm_sched_entity_compare_before(struct rb_node *a, 
	return ktime_before(ent_a->oldest_job_waiting, ent_b->oldest_job_waiting);

}



static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *entity)

static void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *entity,

					    struct drm_sched_rq *rq)

{

	struct drm_sched_rq *rq = entity->rq;



	if (!RB_EMPTY_NODE(&entity->rb_tree_node)) {

		rb_erase_cached(&entity->rb_tree_node, &rq->rb_tree_root);

		RB_CLEAR_NODE(&entity->rb_tree_node);

	}

}



void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity, ktime_t ts)

void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity,

				     struct drm_sched_rq *rq,

				     ktime_t ts)

{

	/*

	 * Both locks need to be grabbed, one to protect from entity->rq change
@@ -171,17 +172,14 @@ void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity, ktime_t ts 
	 * other to update the rb tree structure.

	 */

	lockdep_assert_held(&entity->lock);

	lockdep_assert_held(&rq->lock);



	spin_lock(&entity->rq->lock);



	drm_sched_rq_remove_fifo_locked(entity);

	drm_sched_rq_remove_fifo_locked(entity, rq);



	entity->oldest_job_waiting = ts;



	rb_add_cached(&entity->rb_tree_node, &entity->rq->rb_tree_root,

	rb_add_cached(&entity->rb_tree_node, &rq->rb_tree_root,

		      drm_sched_entity_compare_before);



	spin_unlock(&entity->rq->lock);

}



/**
@@ -213,15 +211,14 @@ static void drm_sched_rq_init(struct drm_gpu_scheduler *sched, 
void drm_sched_rq_add_entity(struct drm_sched_rq *rq,

			     struct drm_sched_entity *entity)

{

	lockdep_assert_held(&entity->lock);

	lockdep_assert_held(&rq->lock);



	if (!list_empty(&entity->list))

		return;



	spin_lock(&rq->lock);



	atomic_inc(rq->sched->score);

	list_add_tail(&entity->list, &rq->entities);



	spin_unlock(&rq->lock);

}



/**
@@ -235,6 +232,8 @@ void drm_sched_rq_add_entity(struct drm_sched_rq *rq, 
void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,

				struct drm_sched_entity *entity)

{

	lockdep_assert_held(&entity->lock);



	if (list_empty(&entity->list))

		return;
@@ -247,7 +246,7 @@ void drm_sched_rq_remove_entity(struct drm_sched_rq *rq, 
		rq->current_entity = NULL;



	if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)

		drm_sched_rq_remove_fifo_locked(entity);

		drm_sched_rq_remove_fifo_locked(entity, rq);



	spin_unlock(&rq->lock);

}

include/drm/gpu_scheduler.h

+2 −1
Original line number Diff line number Diff line
@@ -596,7 +596,8 @@ void drm_sched_rq_add_entity(struct drm_sched_rq *rq, 
void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,

				struct drm_sched_entity *entity);



void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity, ktime_t ts);

void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity,

				     struct drm_sched_rq *rq, ktime_t ts);



int drm_sched_entity_init(struct drm_sched_entity *entity,

			  enum drm_sched_priority priority,