Setting seeds for TestRoiPool backward. (#4763)

test/test_ops.py

@@ -46,9 +46,11 @@ class RoIOpTester(ABC):
         tol = 1e-3 if (x_dtype is torch.half or rois_dtype is torch.half) else 1e-5
         torch.testing.assert_close(gt_y.to(y), y, rtol=tol, atol=tol)
 
+    @pytest.mark.parametrize("seed", range(10))
     @pytest.mark.parametrize("device", cpu_and_gpu())
     @pytest.mark.parametrize("contiguous", (True, False))
-    def test_backward(self, device, contiguous):
+    def test_backward(self, seed, device, contiguous):
+        torch.random.manual_seed(seed)
         pool_size = 2
         x = torch.rand(1, 2 * (pool_size ** 2), 5, 5, dtype=self.dtype, device=device, requires_grad=True)
         if not contiguous: