drm/amdgpu: minor optimize VM moved handling v2

Try to lock moved BOs if it's successful we can update the
PTEs directly to the new location.

v2: rebase

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@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 3632c69..c1c5ccd 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1697,18 +1697,31 @@ int amdgpu_vm_handle_moved(struct amdgpu_device *adev,
        spin_lock(&vm->status_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->status_lock);
 
+               resv = bo_va->base.bo->tbo.resv;
+
                /* Per VM BOs never need to bo cleared in the page tables */
-               clear = bo_va->base.bo->tbo.resv != vm->root.base.bo->tbo.resv;
+               if (resv == vm->root.base.bo->tbo.resv)
+                       clear = false;
+               /* Try to reserve the BO to avoid clearing its ptes */
+               else if (reservation_object_trylock(resv))
+                       clear = false;
+               /* Somebody else is using the BO right now */
+               else
+                       clear = true;
 
                r = amdgpu_vm_bo_update(adev, bo_va, clear);
                if (r)
                        return r;
 
+               if (!clear && resv != vm->root.base.bo->tbo.resv)
+                       reservation_object_unlock(resv);
+
                spin_lock(&vm->status_lock);
        }
        spin_unlock(&vm->status_lock);