Add sanity checks to dtensor tests

ghstack-source-id: 0f3887b4a5b87ea63adb8d09a2edfabdd4868e0a
Pull Request resolved: #302

test/test_dtensor.py

@@ -248,6 +248,12 @@ def test_fp8_mlp_tensor_parallelism_base(
     x_fp32_sp_input = distribute_tensor(x_fp32.clone(), mesh, [Shard(0)])
 
     tp_out = tp_model(x_fp32_tp_input)
+    assert (
+        tp_model.ffn.w1.weight.requires_grad
+    ), "Expecting gradients to be enabled for TP model."
+    assert tp_out.requires_grad, "Expecting gradients to be enabled for TP model."
+    awaited_out = tp_out.wait()
+    assert awaited_out.requires_grad, "Expecting awaited out to require gradients"
     tp_out.sum().backward()
     sp_out = sp_model(x_fp32_sp_input)
     sp_out.sum().backward()