drm/amdgpu: further optimize amdgpu_vm_handle_moved

Splice the moved list to a local one to avoid taking the lock over and
over again.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 3be4d5f..4d88b06 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1781,19 +1781,18 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
 int amdgpu_vm_handle_moved(struct amdgpu_device *adev,
                           struct amdgpu_vm *vm)
 {
+       struct amdgpu_bo_va *bo_va, *tmp;
+       struct list_head moved;
        bool clear;
-       int r = 0;
+       int r;
 
+       INIT_LIST_HEAD(&moved);
        spin_lock(&vm->moved_lock);
-       while (!list_empty(&vm->moved)) {
-               struct amdgpu_bo_va *bo_va;
-               struct reservation_object *resv;
-
-               bo_va = list_first_entry(&vm->moved,
-                       struct amdgpu_bo_va, base.vm_status);
-               spin_unlock(&vm->moved_lock);
+       list_splice_init(&vm->moved, &moved);
+       spin_unlock(&vm->moved_lock);
 
-               resv = bo_va->base.bo->tbo.resv;
+       list_for_each_entry_safe(bo_va, tmp, &moved, base.vm_status) {
+               struct reservation_object *resv = bo_va->base.bo->tbo.resv;
 
                /* Per VM BOs never need to bo cleared in the page tables */
                if (resv == vm->root.base.bo->tbo.resv)
@@ -1806,17 +1805,19 @@ int amdgpu_vm_handle_moved(struct amdgpu_device *adev,
                        clear = true;
 
                r = amdgpu_vm_bo_update(adev, bo_va, clear);
-               if (r)
+               if (r) {
+                       spin_lock(&vm->moved_lock);
+                       list_splice(&moved, &vm->moved);
+                       spin_unlock(&vm->moved_lock);
                        return r;
+               }
 
                if (!clear && resv != vm->root.base.bo->tbo.resv)
                        reservation_object_unlock(resv);
 
-               spin_lock(&vm->moved_lock);
        }
-       spin_unlock(&vm->moved_lock);
 
-       return r;
+       return 0;
 }
 
 /**