[legacy] move communication and nn to legacy and refactor logger (#4671)

* [legacy] move communication to legacy (#4640)

* [legacy] refactor logger and clean up legacy codes (#4654)

* [legacy] make logger independent to gpc

* [legacy] make optim independent to registry

* [legacy] move test engine to legacy

* [legacy] move nn to legacy (#4656)

* [legacy] move nn to legacy

* [checkpointio] fix save hf config

* [test] remove useledd rpc pp test

* [legacy] fix nn init

* [example] skip tutorial hybriad parallel example

* [devops] test doc check

* [devops] test doc check

colossalai/utils/common.py

@@ -470,3 +470,22 @@ def disposable(func: Callable) -> Callable:
             return func(*args, **kwargs)
 
     return wrapper
+
+
+def free_storage(data: torch.Tensor) -> None:
+    """Free underlying storage of a Tensor."""
+    if data.storage().size() > 0:
+        # Since we're modifying the Tensor's Storage directly, make sure the Tensor
+        # is the sole occupant of the Storage.
+        assert data.storage_offset() == 0
+        data.storage().resize_(0)
+
+
+def _cast_float(args, dtype: torch.dtype):
+    if isinstance(args, torch.Tensor) and torch.is_floating_point(args):
+        args = args.to(dtype)
+    elif isinstance(args, (list, tuple)):
+        args = type(args)(_cast_float(t, dtype) for t in args)
+    elif isinstance(args, dict):
+        args = {k: _cast_float(v, dtype) for k, v in args.items()}
+    return args