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From 34147464b6e29c6468a3bec16b2e1e2f8b3200eb Mon Sep 17 00:00:00 2001
From: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Date: Tue, 15 May 2018 14:42:20 -0400
Subject: [PATCH 4447/5725] 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 <andrey.grodzovsky@amd.com>
Acked-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
---
drivers/gpu/drm/scheduler/gpu_scheduler.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler.c b/drivers/gpu/drm/scheduler/gpu_scheduler.c
index 026e0d8..be5d321 100644
--- a/drivers/gpu/drm/scheduler/gpu_scheduler.c
+++ b/drivers/gpu/drm/scheduler/gpu_scheduler.c
@@ -138,7 +138,6 @@ 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);
@@ -412,6 +411,10 @@ 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,
@@ -422,11 +425,8 @@ 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 */
@@ -592,7 +592,12 @@ 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,
--
2.7.4
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