drm/amdgpu: fix unnecessary wake up

decrease CPU extra overhead.

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

2 files changed, 7 insertions, 4 deletions

diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
index 5017c71ba700..3d45ff29eaa8 100644
--- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
+++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
@@ -158,7 +158,7 @@ exit:
         if (sched->current_entity && (sched->current_entity != tmp))
                 wake_entity = sched->current_entity;
         sched->current_entity = tmp;
-        if (wake_entity)
+        if (wake_entity && wake_entity->need_wakeup)
                 wake_up(&wake_entity->wait_queue);
         return tmp;
 }
@@ -195,6 +195,7 @@ int amd_sched_entity_init(struct amd_gpu_scheduler *sched,
         entity->fence_context = fence_context_alloc(1);
         snprintf(name, sizeof(name), "c_entity[%llu]", entity->fence_context);
         memcpy(entity->name, name, 20);
+        entity->need_wakeup = false;
         if(kfifo_alloc(&entity->job_queue,
                        jobs * sizeof(void *),
                        GFP_KERNEL))
@@ -257,7 +258,7 @@ int amd_sched_entity_fini(struct amd_gpu_scheduler *sched,
 
         if (!is_context_entity_initialized(sched, entity))
                 return 0;
-
+        entity->need_wakeup = true;
         /**
          * The client will not queue more IBs during this fini, consume existing
          * queued IBs
@@ -323,8 +324,9 @@ int amd_sched_push_job(struct amd_gpu_scheduler *sched,
                 */
                 schedule();
         }
-
-        wake_up_interruptible(&sched->wait_queue);
+        /* first job wake up scheduler */
+        if ((kfifo_len(&c_entity->job_queue) / sizeof(void *)) == 1)
+                wake_up_interruptible(&sched->wait_queue);
         return 0;
 }
 
diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
index 5e35018ad7b8..47823b4a71e0 100644
--- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
+++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
@@ -54,6 +54,7 @@ struct amd_sched_entity {
         bool                            is_pending;
         uint64_t                        fence_context;
         char                            name[20];
+        bool                            need_wakeup;
 };
 
 /**