ColossalAI/colossalai/utils/model/colo_init_context.py

99 lines
3.6 KiB
Python

from .utils import InsertPostInitMethodToModuleSubClasses
import torch
from colossalai.tensor import ColoTensor, ColoParameter
from colossalai.nn.parallel.layers import register_colo_module, \
ColoLinear, ColoEmbedding
from torch import nn
from typing import Iterator, Tuple, Union
# find named_params includes replica
def _named_params_with_replica(
module: nn.Module,
prefix: str = '',
recurse: bool = True,
) -> Iterator[Tuple[str, Union[nn.Parameter, ColoTensor]]]:
modules = module.named_modules(prefix=prefix) if recurse else [(prefix, module)]
for mod_prefix, mod in modules:
for name, val in mod._parameters.items():
if val is None:
continue
name = mod_prefix + ('.' if mod_prefix else '') + name
yield name, val
def ColoModulize(module):
"""
Replacing the parameters() and named_parameters() with our customized ones
"""
module._colo_visited = True
class ColoInitContext(InsertPostInitMethodToModuleSubClasses):
def __init__(self, lazy_memory_allocate: bool = False, device: torch.device = torch.device('cpu')):
"""
Args:
lazy_memory_allocate (bool, optional): whether to allocate memory for the parameter tensors. Defaults to False.
device (torch.device, optional): the device parameters initialized are resident on. Defaults to torch.device('cpu').
"""
super().__init__()
self._lazy_memory_allocate = lazy_memory_allocate
self._device = device
self._register_colo_modules()
def _register_colo_modules(self):
register_colo_module(torch.nn.Linear, ColoLinear())
register_colo_module(torch.nn.Embedding, ColoEmbedding())
def _pre_context_exec(self):
pass
def _post_init_method(self, module: torch.nn.Module, *args, **kwargs):
"""
The function to call at the end of the constructor of each module.
FIXME(fjr) The module may be passed to this function multiple times?
"""
if hasattr(module, '_colo_visited'):
return
name_list = []
for name, param in _named_params_with_replica(module):
if isinstance(param, ColoTensor):
continue
split = name.rfind('.')
if split >= 0: # param in submodule
module_name = name[:split]
param_name = name[split + 1:]
else:
module_name = '' # param in current module
param_name = name
name_list.append((module_name, param_name))
replaced_tensors = dict(
) # record mapping between (torch.Tensor, ColoTensor) to distinguish the same reference
for module_name, param_name in name_list:
submodule = module.get_submodule(module_name)
param = submodule.get_parameter(param_name)
if param in replaced_tensors:
colo_param = replaced_tensors[param]
else:
save_torch_payload = True if not self._lazy_memory_allocate else False
# detaching tensor is necessary for optimizers.
requires_grad = param.requires_grad
# TODO(jiaruifang) we initialize a Default PG memory
colo_param = ColoParameter(param.to(self._device), requires_grad=requires_grad)
# add mapping record
replaced_tensors[param] = colo_param
delattr(submodule, param_name)
setattr(submodule, param_name, colo_param)
colo_param.shared_param_modules.append(submodule)
module.to(self._device)
ColoModulize(module)