fix

colossalai/checkpoint_io/utils.py

@@ -314,7 +314,7 @@ def save_state_dict(state_dict: dict, checkpoint_file_path: str, use_safetensors
         use_safetensors (bool): whether to use safetensors to save the checkpoint.
     """
     # Move all tensors in the state_dict to CPU before saving to avoid serialization issues
-    state_dict_cpu = tree_map(lambda x: x.cpu() if torch.is_tensor(x) else x, state_dict)
+    state_dict_cpu = tree_map(lambda x: x.data.cpu() if torch.is_tensor(x) else x, state_dict)
 
     if use_safetensors:
         assert is_safetensors_available(), "safetensors is not available."