80 lines
3.0 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Utils for model executor."""
import copy
from typing import Any, Optional
import torch
def set_random_seed(seed: int) -> None:
from vllm.platforms import current_platform
current_platform.seed_everything(seed)
def set_weight_attrs(
weight: torch.Tensor,
weight_attrs: Optional[dict[str, Any]],
):
"""Set attributes on a weight tensor.
This method is used to set attributes on a weight tensor. This method
will not overwrite existing attributes.
Args:
weight: The weight tensor.
weight_attrs: A dictionary of attributes to set on the weight tensor.
"""
if weight_attrs is None:
return
for key, value in weight_attrs.items():
assert not hasattr(
weight, key), (f"Overwriting existing tensor attribute: {key}")
# NOTE(woosuk): During weight loading, we often do something like:
# narrowed_tensor = param.data.narrow(0, offset, len)
# narrowed_tensor.copy_(real_weight)
# expecting narrowed_tensor and param.data to share the same storage.
# However, on TPUs, narrowed_tensor will lazily propagate to the base
# tensor, which is param.data, leading to the redundant memory usage.
# This sometimes causes OOM errors during model loading. To avoid this,
# we sync the param tensor after its weight loader is called.
# TODO(woosuk): Remove this hack once we have a better solution.
from vllm.platforms import current_platform
if current_platform.is_tpu() and key == "weight_loader":
value = _make_synced_weight_loader(value)
setattr(weight, key, value)
def _make_synced_weight_loader(original_weight_loader):
def _synced_weight_loader(param, *args, **kwargs):
original_weight_loader(param, *args, **kwargs)
# torch._sync doesn't support, is not needed for CPU tensors.
if param.device != torch.device("cpu"):
torch._sync(param)
return _synced_weight_loader
def get_packed_modules_mapping(model: torch.nn.Module) -> dict[str, list[str]]:
parent_map = getattr(model, "packed_modules_mapping", None)
parent_map = copy.deepcopy(parent_map) if parent_map is not None else {}
# don't infer mapping if the model has defined it explicitly.
if parent_map:
return parent_map
# We only check main components instead of whole model submodules
for child in model.children():
child_map = getattr(child, "packed_modules_mapping", None)
child_map = copy.deepcopy(child_map) if child_map is not None else {}
if any((k in parent_map and parent_map[k] != v)
for k, v in child_map.items()):
raise ValueError(
f"Can't update {type(model).__name__}'s packed_modules_mapping "
f"safely because of conflicts from {type(child).__name__}.")
else:
parent_map.update(child_map)
return parent_map