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2026-07-13 13:18:33 +08:00

104 lines
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Python

# Copyright (c) Microsoft Corporation.
# SPDX-License-Identifier: Apache-2.0
# DeepSpeed Team
from dataclasses import dataclass, field
from typing import Any, Dict, List, Tuple
from functools import reduce
import torch
from torch.fx import Graph, Node
from .fx import get_output_node
from .util import get_param_nodes, get_input_nodes
@dataclass
class DSGraphParam:
name: str
shape: torch.Size
dtype: torch.dtype
device: torch.device
node: Node
allgather_node: Node
release_node: Node
param: torch.Tensor
numel: int = field(init=False)
def __post_init__(self):
self.numel = reduce(lambda x, y: x * y, self.shape)
class DSGraphParamManager:
def __init__(self, fw_graph: Graph, sample_inputs: Any, index_to_ds_ids: List[Tuple[int, int, int]]):
self._fw_graph = fw_graph
self._bw_graph = None
self._params: Dict[str, DSGraphParam] = {}
self._param_name_to_grad: Dict[str, Node] = {}
self._ds_ids: Dict[str, int] = {}
param_nodes = get_param_nodes(fw_graph, index_to_ds_ids)
self._param_names = [pn.name for pn in param_nodes]
self._param_indices = [i for i, _, _ in index_to_ds_ids]
param_inputs = [sample_inputs[i] for i, _, _ in index_to_ds_ids]
ds_ids = [ds_id for _, ds_id, _ in index_to_ds_ids]
ds_shapes = [ds_shape for _, _, ds_shape in index_to_ds_ids]
for pn, pi, ds_id, ds_shape in zip(param_nodes, param_inputs, ds_ids, ds_shapes):
self._params[pn.name] = DSGraphParam(name=pn.name,
shape=ds_shape,
dtype=pi.dtype,
device=pi.device,
node=pn,
allgather_node=None,
release_node=None,
param=pi)
self._ds_ids[pn.name] = ds_id
def get_bwd_mapping(self, bw_graph: Graph):
self._bw_graph = bw_graph
output_node = get_output_node(bw_graph)
param_nodes_bw = [n for n in self._bw_graph.nodes if n.name in self.param_names]
grad_outputs = [output_node.args[0][i] for i in self._param_indices]
param_name_to_grad = {param_name: grad for param_name, grad in zip(self.param_names, grad_outputs)}
return param_nodes_bw, param_name_to_grad
@property
def param_names(self) -> List[str]:
return self._param_names
@property
def params(self) -> Dict[str, DSGraphParam]:
return self._params
@property
def ds_ids(self) -> Dict[str, int]:
return self._ds_ids
def get_grad_name(self, param_name) -> str:
assert self._param_name_to_grad is not None, "Backward graph is not added yet"
return self._param_name_to_grad[param_name]
def replace_fake_tensors_with_real_params(self, sample_inputs: List[Any], bw_graph: Graph) -> List[Any]:
"""Replace fake tensors in sample_inputs with real parameters from DSGraphParamManager
Args:
sample_inputs: The input tensors that may contain fake tensors
bw_graph: The backward graph to get parameter mapping from (if in backward pass)
"""
replaced_inputs = list(sample_inputs)
# For backward pass, get the parameter nodes and their mapping
param_nodes_bw, _ = self.get_bwd_mapping(bw_graph)
param_names_bw = [n.name for n in param_nodes_bw]
for i, inp in enumerate(get_input_nodes(bw_graph)):
if inp.name in param_names_bw:
replaced_inputs[i] = self._params[inp.name].param
return replaced_inputs