init

model_executor/layers/quantization/utils/layer_utils.py

@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+from typing import Union
+
+import torch
+
+
+def update_tensor_inplace(dst: torch.Tensor, src: torch.Tensor):
+    assert dst.dtype == src.dtype, "Tensors must have the same dtype"
+
+    # update tensor shape and stride
+    dst.as_strided_(src.shape, src.stride())
+
+    # If not the same underlying storage move tensor data
+    if dst.data_ptr() != src.data_ptr():
+        dst.copy_(src)
+        del src
+
+
+# Newly generated tensors need to replace existing tensors that are
+# already registered as parameters by vLLM (and won't be freed)
+def replace_parameter(mod: torch.nn.Module, name: str,
+                      new: Union[torch.Tensor, torch.nn.Parameter]) -> None:
+
+    old = getattr(mod, name)
+    if type(old) is type(new) and old.dtype == new.dtype and \
+        old.untyped_storage().nbytes() == new.untyped_storage().nbytes():
+        # If we can just update in-place to avoid re-registering
+        #   can be faster if the underlying storage is the same
+        update_tensor_inplace(old, new)
+    else:
+        # Fallback re-register parameter, convert to Parameter if necessary
+        # this not only ensures we don't register a tensor as a parameter, but
+        # also ensures that all parameter subclasses get re-registered as
+        # parameters for `torch.compile` compatibility
+        if not isinstance(new, torch.nn.Parameter):
+            new = torch.nn.Parameter(new, requires_grad=False)
+        mod.register_parameter(name,
+                               torch.nn.Parameter(new, requires_grad=False))