drm/amdgpu: Optimize mutex usage (v4)
In original function amdgpu_bo_list_get, the waiting
for result->lock can be quite long while mutex
bo_list_lock was holding. It can make other tasks
waiting for bo_list_lock for long period.
Secondly, this patch allows several tasks(readers of idr)
to proceed at the same time.
v2: use rcu and kref (Dave Airlie and Christian König)
v3: update v1 commit message (Michel Dänzer)
v4: rebase on upstream (Alex Deucher)
Signed-off-by: Alex Xie <AlexBin.Xie@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 9f827ac..12d61ed 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -869,6 +869,8 @@ struct amdgpu_fpriv {
struct amdgpu_bo_list {
struct mutex lock;
+ struct rcu_head rhead;
+ struct kref refcount;
struct amdgpu_bo *gds_obj;
struct amdgpu_bo *gws_obj;
struct amdgpu_bo *oa_obj;