Format tensor on cpu (#8548)

* Format tensor on cpu

* use tensor.detach

python/oneflow/framework/tensor_str.py

@@ -339,6 +339,14 @@ def get_summarized_data(self):
         )
 
 
+def _format_tensor_on_cpu(tensor):
+    if tensor.is_global:
+        device = tensor.placement.type
+    else:
+        device = tensor.device.type
+    return device != "cpu" and device != "cuda"
+
+
 def _gen_tensor_str_template(tensor, is_meta):
     is_meta = is_meta or tensor.is_lazy
     prefix = "tensor("
@@ -349,10 +357,8 @@ def _gen_tensor_str_template(tensor, is_meta):
     if tensor.is_global:
         suffixes.append(f"placement={str(tensor.placement)}")
         suffixes.append(f"sbp={str(tensor.sbp)}")
-    elif tensor.device.type == "cuda":
-        suffixes.append("device='" + str(tensor.device) + "'")
     elif tensor.device.type != "cpu":
-        raise RunTimeError("unknow device type")
+        suffixes.append("device='" + str(tensor.device) + "'")
     if tensor.is_lazy:
         suffixes.append("is_lazy='True'")
 
@@ -366,7 +372,10 @@ def _gen_tensor_str_template(tensor, is_meta):
         tensor_str = "..."
         suffixes.append("size=" + str(tuple(tensor.shape)))
     else:
-        tensor_str = _tensor_str(tensor, indent)
+        if _format_tensor_on_cpu(tensor):
+            tensor_str = _tensor_str(tensor.detach().to("cpu"), indent)
+        else:
+            tensor_str = _tensor_str(tensor, indent)
 
     suffixes.append("dtype=" + str(tensor.dtype))
     if tensor.grad_fn is not None: