From 563e1e664d27292a3b55ca08366dc8c32db52450 Mon Sep 17 00:00:00 2001 From: Andrey Grodzovsky Date: Tue, 15 May 2018 14:42:20 -0400 Subject: [PATCH] drm/scheduler: Remove obsolete spinlock. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This spinlock is superfluous, any call to drm_sched_entity_push_job should already be under a lock together with matching drm_sched_job_init to match the order of insertion into queue with job's fence seqence number. v2: Improve patch description. Add functions documentation describing the locking considerations Signed-off-by: Andrey Grodzovsky Acked-by: Chunming Zhou Reviewed-by: Christian König Signed-off-by: Alex Deucher --- drivers/gpu/drm/scheduler/gpu_scheduler.c | 15 ++++++++++----- include/drm/gpu_scheduler.h | 1 - 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler.c b/drivers/gpu/drm/scheduler/gpu_scheduler.c index a364fc0b38c3..df1578d6f42e 100644 --- a/drivers/gpu/drm/scheduler/gpu_scheduler.c +++ b/drivers/gpu/drm/scheduler/gpu_scheduler.c @@ -139,7 +139,6 @@ int drm_sched_entity_init(struct drm_gpu_scheduler *sched, entity->last_scheduled = NULL; spin_lock_init(&entity->rq_lock); - spin_lock_init(&entity->queue_lock); spsc_queue_init(&entity->job_queue); atomic_set(&entity->fence_seq, 0); @@ -413,6 +412,10 @@ drm_sched_entity_pop_job(struct drm_sched_entity *entity) * * @sched_job The pointer to job required to submit * + * Note: To guarantee that the order of insertion to queue matches + * the job's fence sequence number this function should be + * called with drm_sched_job_init under common lock. + * * Returns 0 for success, negative error code otherwise. */ void drm_sched_entity_push_job(struct drm_sched_job *sched_job, @@ -423,11 +426,8 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job, trace_drm_sched_job(sched_job, entity); - spin_lock(&entity->queue_lock); first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node); - spin_unlock(&entity->queue_lock); - /* first job wakes up scheduler */ if (first) { /* Add the entity to the run queue */ @@ -593,7 +593,12 @@ void drm_sched_job_recovery(struct drm_gpu_scheduler *sched) } EXPORT_SYMBOL(drm_sched_job_recovery); -/* init a sched_job with basic field */ +/** + * Init a sched_job with basic field + * + * Note: Refer to drm_sched_entity_push_job documentation + * for locking considerations. + */ int drm_sched_job_init(struct drm_sched_job *job, struct drm_gpu_scheduler *sched, struct drm_sched_entity *entity, diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index 52380067a43f..dec655894d08 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -56,7 +56,6 @@ struct drm_sched_entity { spinlock_t rq_lock; struct drm_gpu_scheduler *sched; - spinlock_t queue_lock; struct spsc_queue job_queue; atomic_t fence_seq;