Re: [PATCH 7/8] drm/sched: Re-group and rename the entity run-queue lock

[Christian König <christian.koenig@xxxxxxx>]

Am 09.09.24 um 19:19 schrieb Tvrtko Ursulin:
> From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxx>
>
> Christian suggested to rename the lock and improve the documentation of
> what it protects. And to also re-order the structure members so all
> protected by the lock are together in a block.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxx>
> Cc: Christian König <christian.koenig@xxxxxxx>
> Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> Cc: Luben Tuikov <ltuikov89@xxxxxxxxx>
> Cc: Matthew Brost <matthew.brost@xxxxxxxxx>
> Cc: Philipp Stanner <pstanner@xxxxxxxxxx>

Reviewed-by: Christian König <christian.koenig@xxxxxxx>

> ---
>   drivers/gpu/drm/scheduler/sched_entity.c | 24 ++++++++++++------------
>   drivers/gpu/drm/scheduler/sched_main.c   |  6 +++---
>   include/drm/gpu_scheduler.h              | 15 ++++++++-------
>   3 files changed, 23 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
> index 2da677681291..b4c4f9923e0b 100644
> --- a/drivers/gpu/drm/scheduler/sched_entity.c
> +++ b/drivers/gpu/drm/scheduler/sched_entity.c
> @@ -105,7 +105,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity,
>   	/* We start in an idle state. */
>   	complete_all(&entity->entity_idle);
>   
> -	spin_lock_init(&entity->rq_lock);
> +	spin_lock_init(&entity->lock);
>   	spsc_queue_init(&entity->job_queue);
>   
>   	atomic_set(&entity->fence_seq, 0);
> @@ -133,10 +133,10 @@ void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
>   {
>   	WARN_ON(!num_sched_list || !sched_list);
>   
> -	spin_lock(&entity->rq_lock);
> +	spin_lock(&entity->lock);
>   	entity->sched_list = sched_list;
>   	entity->num_sched_list = num_sched_list;
> -	spin_unlock(&entity->rq_lock);
> +	spin_unlock(&entity->lock);
>   }
>   EXPORT_SYMBOL(drm_sched_entity_modify_sched);
>   
> @@ -244,10 +244,10 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity)
>   	if (!entity->rq)
>   		return;
>   
> -	spin_lock(&entity->rq_lock);
> +	spin_lock(&entity->lock);
>   	entity->stopped = true;
>   	drm_sched_rq_remove_entity(entity->rq, entity);
> -	spin_unlock(&entity->rq_lock);
> +	spin_unlock(&entity->lock);
>   
>   	/* Make sure this entity is not used by the scheduler at the moment */
>   	wait_for_completion(&entity->entity_idle);
> @@ -396,9 +396,9 @@ static void drm_sched_entity_wakeup(struct dma_fence *f,
>   void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
>   				   enum drm_sched_priority priority)
>   {
> -	spin_lock(&entity->rq_lock);
> +	spin_lock(&entity->lock);
>   	entity->priority = priority;
> -	spin_unlock(&entity->rq_lock);
> +	spin_unlock(&entity->lock);
>   }
>   EXPORT_SYMBOL(drm_sched_entity_set_priority);
>   
> @@ -555,14 +555,14 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
>   	if (fence && !dma_fence_is_signaled(fence))
>   		return;
>   
> -	spin_lock(&entity->rq_lock);
> +	spin_lock(&entity->lock);
>   	sched = drm_sched_pick_best(entity->sched_list, entity->num_sched_list);
>   	rq = sched ? sched->sched_rq[entity->priority] : NULL;
>   	if (rq != entity->rq) {
>   		drm_sched_rq_remove_entity(entity->rq, entity);
>   		entity->rq = rq;
>   	}
> -	spin_unlock(&entity->rq_lock);
> +	spin_unlock(&entity->lock);
>   
>   	if (entity->num_sched_list == 1)
>   		entity->sched_list = NULL;
> @@ -602,9 +602,9 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
>   		struct drm_sched_rq *rq;
>   
>   		/* Add the entity to the run queue */
> -		spin_lock(&entity->rq_lock);
> +		spin_lock(&entity->lock);
>   		if (entity->stopped) {
> -			spin_unlock(&entity->rq_lock);
> +			spin_unlock(&entity->lock);
>   
>   			DRM_ERROR("Trying to push to a killed entity\n");
>   			return;
> @@ -619,7 +619,7 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
>   		if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
>   			drm_sched_rq_update_fifo_locked(entity, submit_ts);
>   
> -		spin_unlock(&entity->rq_lock);
> +		spin_unlock(&entity->lock);
>   
>   		drm_sched_wakeup(sched, entity);
>   	}
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index 54c5fe7a7d1d..937e7d1cfc49 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -165,7 +165,7 @@ static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *enti
>   
>   void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity, ktime_t ts)
>   {
> -	lockdep_assert_held(&entity->rq_lock);
> +	lockdep_assert_held(&entity->lock);
>   
>   	spin_lock(&entity->rq->lock);
>   
> @@ -186,9 +186,9 @@ void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts)
>   	 * for entity from within concurrent drm_sched_entity_select_rq and the
>   	 * other to update the rb tree structure.
>   	 */
> -	spin_lock(&entity->rq_lock);
> +	spin_lock(&entity->lock);
>   	drm_sched_rq_update_fifo_locked(entity, ts);
> -	spin_unlock(&entity->rq_lock);
> +	spin_unlock(&entity->lock);
>   }
>   
>   /**
> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
> index d4a3ba333568..5a1e4c803b90 100644
> --- a/include/drm/gpu_scheduler.h
> +++ b/include/drm/gpu_scheduler.h
> @@ -96,6 +96,14 @@ struct drm_sched_entity {
>   	 */
>   	struct list_head		list;
>   
> +	/**
> +	 * @lock:
> +	 *
> +	 * Lock protecting the run-queue (@rq) to which this entity belongs,
> +	 * @priority and the list of schedulers (@sched_list, @num_sched_list).
> +	 */
> +	spinlock_t			lock;
> +
>   	/**
>   	 * @rq:
>   	 *
> @@ -140,13 +148,6 @@ struct drm_sched_entity {
>   	 */
>   	enum drm_sched_priority         priority;
>   
> -	/**
> -	 * @rq_lock:
> -	 *
> -	 * Lock to modify the runqueue to which this entity belongs.
> -	 */
> -	spinlock_t			rq_lock;
> -
>   	/**
>   	 * @job_queue: the list of jobs of this entity.
>   	 */