drm/amdgpu: let the scheduler work more with jobs v2

v2: fix another race condition

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>

diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
index d99fe90991dc47344974f43e6d078f3314469308..205cb887d02320fc55d573de23f923f0be82139e 100644 (file)
--- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
+++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
@@ -27,6 +27,8 @@
 #include <drm/drmP.h>
 #include "gpu_scheduler.h"
 
+static struct amd_sched_job *
+amd_sched_entity_pop_job(struct amd_sched_entity *entity);
 static void amd_sched_wakeup(struct amd_gpu_scheduler *sched);
 
 /* Initialize a given run queue struct */
@@ -56,34 +58,36 @@ static void amd_sched_rq_remove_entity(struct amd_sched_rq *rq,
 }
 
 /**
- * Select next entity from a specified run queue with round robin policy.
- * It could return the same entity as current one if current is the only
- * available one in the queue. Return NULL if nothing available.
+ * Select next job from a specified run queue with round robin policy.
+ * Return NULL if nothing available.
  */
-static struct amd_sched_entity *
-amd_sched_rq_select_entity(struct amd_sched_rq *rq)
+static struct amd_sched_job *
+amd_sched_rq_select_job(struct amd_sched_rq *rq)
 {
        struct amd_sched_entity *entity;
+       struct amd_sched_job *job;
 
        spin_lock(&rq->lock);
 
        entity = rq->current_entity;
        if (entity) {
                list_for_each_entry_continue(entity, &rq->entities, list) {
-                       if (!kfifo_is_empty(&entity->job_queue)) {
+                       job = amd_sched_entity_pop_job(entity);
+                       if (job) {
                                rq->current_entity = entity;
                                spin_unlock(&rq->lock);
-                               return rq->current_entity;
+                               return job;
                        }
                }
        }
 
        list_for_each_entry(entity, &rq->entities, list) {
 
-               if (!kfifo_is_empty(&entity->job_queue)) {
+               job = amd_sched_entity_pop_job(entity);
+               if (job) {
                        rq->current_entity = entity;
                        spin_unlock(&rq->lock);
-                       return rq->current_entity;
+                       return job;
                }
 
                if (entity == rq->current_entity)
@@ -188,6 +192,17 @@ void amd_sched_entity_fini(struct amd_gpu_scheduler *sched,
        kfifo_free(&entity->job_queue);
 }
 
+static struct amd_sched_job *
+amd_sched_entity_pop_job(struct amd_sched_entity *entity)
+{
+       struct amd_sched_job *job;
+
+       if (!kfifo_out_peek(&entity->job_queue, &job, sizeof(job)))
+               return NULL;
+
+       return job;
+}
+
 /**
  * Helper to submit a job to the job queue
  *
@@ -260,22 +275,22 @@ static void amd_sched_wakeup(struct amd_gpu_scheduler *sched)
 }
 
 /**
- * Select next entity containing real IB submissions
+ * Select next to run
 */
-static struct amd_sched_entity *
-amd_sched_select_context(struct amd_gpu_scheduler *sched)
+static struct amd_sched_job *
+amd_sched_select_job(struct amd_gpu_scheduler *sched)
 {
-       struct amd_sched_entity *tmp;
+       struct amd_sched_job *job;
 
        if (!amd_sched_ready(sched))
                return NULL;
 
        /* Kernel run queue has higher priority than normal run queue*/
-       tmp = amd_sched_rq_select_entity(&sched->kernel_rq);
-       if (tmp == NULL)
-               tmp = amd_sched_rq_select_entity(&sched->sched_rq);
+       job = amd_sched_rq_select_job(&sched->kernel_rq);
+       if (job == NULL)
+               job = amd_sched_rq_select_job(&sched->sched_rq);
 
-       return tmp;
+       return job;
 }
 
 static void amd_sched_process_job(struct fence *f, struct fence_cb *cb)
@@ -301,22 +316,19 @@ static int amd_sched_main(void *param)
        sched_setscheduler(current, SCHED_FIFO, &sparam);
 
        while (!kthread_should_stop()) {
-               struct amd_sched_entity *c_entity = NULL;
+               struct amd_sched_entity *entity;
                struct amd_sched_job *job;
                struct fence *fence;
 
                wait_event_interruptible(sched->wake_up_worker,
                        kthread_should_stop() ||
-                       (c_entity = amd_sched_select_context(sched)));
+                       (job = amd_sched_select_job(sched)));
 
-               if (!c_entity)
+               if (!job)
                        continue;
 
-               r = kfifo_out(&c_entity->job_queue, &job, sizeof(void *));
-               if (r != sizeof(void *))
-                       continue;
+               entity = job->s_entity;
                atomic_inc(&sched->hw_rq_count);
-
                fence = sched->ops->run_job(job);
                if (fence) {
                        r = fence_add_callback(fence, &job->cb,
@@ -328,6 +340,7 @@ static int amd_sched_main(void *param)
                        fence_put(fence);
                }
 
+               kfifo_out(&entity->job_queue, &job, sizeof(job));
                wake_up(&sched->job_scheduled);
        }
        return 0;