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ColossalAI/colossalai/checkpoint_io/utils.py

424 lines
14 KiB

# coding=utf-8
import re
from pathlib import Path
from typing import Iterator, List, Mapping, Optional, OrderedDict, Tuple
import torch
import torch.nn as nn
from colossalai.tensor.d_tensor.d_tensor import DTensor
SAFE_WEIGHTS_NAME = "model.safetensors"
WEIGHTS_NAME = "pytorch_model.bin"
SAFE_WEIGHTS_INDEX_NAME = "model.safetensors.index.json"
WEIGHTS_INDEX_NAME = "pytorch_model.bin.index.json"
# ======================================
# General helper functions
# ======================================
def calculate_tensor_size(tensor: torch.Tensor) -> float:
"""
Calculate the size of a parameter in MB. Used to compute whether a group of params exceed the shard size.
If so, a new shard should be created.
Args:
tensor (torch.Tensor): the tensor to calculate size for.
Returns:
float: size of the tensor in MB.
"""
return tensor.numel() * tensor.element_size() / 1024 / 1024
def is_safetensors_available() -> bool:
"""
Check whether safetensors is available.
Returns:
bool: whether safetensors is available.
"""
try:
import safetensors
return True
except ImportError:
return False
def is_dtensor_checkpoint(checkpoint_file_path: str) -> bool:
"""
Check whether the checkpoint file is a dtensor checkpoint.
Args:
checkpoint_file_path (str): path to the checkpoint file.
Returns:
bool: whether the checkpoint file is a dtensor checkpoint.
"""
if checkpoint_file_path.endswith('.*.safetensors') or checkpoint_file_path.endswith('.*.bin'):
return True
else:
return False
def is_safetensor_checkpoint(checkpoint_file_path: str) -> bool:
"""
Check whether the checkpoint file is a safetensor checkpoint.
Args:
checkpoint_file_path (str): path to the checkpoint file.
Returns:
bool: whether the checkpoint file is a safetensor checkpoint.
"""
if checkpoint_file_path.endswith('.safetensors'):
return True
else:
return False
# ======================================
# Helper functions for saving shard file
# ======================================
def shard_checkpoint(state_dict: torch.Tensor, max_shard_size: int = 1024) -> Iterator[Tuple[OrderedDict, int]]:
"""
Splits a model state dictionary in sub-checkpoints so that the final size of each sub-checkpoint does not exceed a
given size.
"""
current_block = {}
current_block_size = 0
for key, weight in state_dict.items():
ret_block = None
ret_block_size = 0
if type(weight) != DTensor:
weight_size = calculate_tensor_size(weight)
# If this weight is going to tip up over the maximal size, we split.
if current_block_size + weight_size > max_shard_size:
ret_block = current_block
ret_block_size = current_block_size
current_block = {}
current_block_size = 0
current_block[key] = weight
current_block_size += weight_size
if ret_block != None:
yield ret_block, ret_block_size
yield current_block, current_block_size
def load_shard_state_dict(checkpoint_file: Path, use_safetensors: bool = False):
"""
load shard state dict into model
"""
if use_safetensors and not checkpoint_file.suffix == ".safetensors":
raise Exception("load the model using `safetensors`, but no file endwith .safetensors")
if use_safetensors:
from safetensors.torch import load_file as safe_load_file
from safetensors.torch import safe_open
with safe_open(checkpoint_file, framework="pt") as f:
metadata = f.metadata()
if metadata["format"] != "pt":
raise NotImplementedError(
f"Conversion from a {metadata['format']} safetensors archive to PyTorch is not implemented yet.")
return safe_load_file(checkpoint_file)
else:
return torch.load(checkpoint_file)
def load_state_dict_into_model(model: nn.Module,
state_dict: torch.Tensor,
missing_keys: List,
strict: bool = False,
load_sub_module: bool = True):
r"""Copies parameters and buffers from :attr:`state_dict` into
this module and its descendants.
Args:
state_dict (dict): a dict containing parameters and
persistent buffers.
"""
if not isinstance(state_dict, Mapping):
raise TypeError("Expected state_dict to be dict-like, got {}.".format(type(state_dict)))
unexpected_keys: List[str] = []
sub_missing_keys: List[str] = []
error_msgs: List[str] = []
# copy state_dict so _load_from_state_dict can modify it
metadata = getattr(state_dict, '_metadata', None)
state_dict = OrderedDict(state_dict)
if metadata is not None:
state_dict._metadata = metadata
def load(module: nn.Module, state_dict, prefix="", load_sub_module: bool = True):
local_metadata = {} if metadata is None else metadata.get(prefix[:-1], {})
args = (state_dict, prefix, local_metadata, True, sub_missing_keys, [], error_msgs)
# Parameters of module and children will start with prefix. We can exit early if there are none in this
# state_dict
if len([key for key in state_dict if key.startswith(prefix)]) > 0:
module._load_from_state_dict(*args)
if load_sub_module:
for name, child in module._modules.items():
if child is not None:
load(child, state_dict, prefix + name + ".")
load(model, state_dict, "", load_sub_module)
del load
missing_keys = missing_keys.append(sub_missing_keys)
if strict:
if len(unexpected_keys) > 0:
error_msgs = 'Unexpected key(s) in state_dict: {}. '.format(', '.join(
'"{}"'.format(k) for k in unexpected_keys))
raise RuntimeError('Error(s) in loading state_dict for {}:\n\t{}'.format(
model.__class__.__name__, "\n\t".join(error_msgs)))
# ======================================
# Helper functions for saving state dict
# ======================================
def save_state_dict(state_dict: dict, checkpoint_file_path: str, use_safetensors: bool) -> None:
"""
Save state dict to checkpoint.
Args:
state_dict (dict): state dict.
checkpoint_file_path (str): path to the checkpoint file.
use_safetensors (bool): whether to use safetensors to save the checkpoint.
"""
if use_safetensors:
assert is_safetensors_available(), "safetensors is not available."
assert checkpoint_file_path.endswith('.safetensors'), \
"safetensors only supports .safetensors suffix for checkpoint file."
from safetensors.torch import save_file as safe_save_file
safe_save_file(state_dict, checkpoint_file_path, metadata={"format": "pt"})
else:
torch.save(state_dict, checkpoint_file_path)
def save_dtensor(name: str, tensor: torch.Tensor, index_file: "CheckpointIndexFile", use_safetensors: bool) -> None:
"""
Save distributed tensor to checkpoint. This checkpoint will be a dictionary which contains
only one tensor.
Args:
tensor (Tensor): tensor to be saved.
index_file (CheckpointIndexFile): path to the checkpoint file.
size_per_shard (int): size per shard in MB.
"""
root_path = index_file.root_path
output_root_path = root_path.joinpath('dtensor')
# create directory
output_root_path.mkdir(exist_ok=True)
# save tensor to this directory
# TODO(YuliangLiu): get index of the tensor shard
# e.g. index =
index = 0
# save tensor to file
ckpt_file_name = generate_dtensor_file_name(name, index, use_safetensors)
ckpt_file_path = output_root_path.joinpath(ckpt_file_name)
# dtensor ckpt file always contains only one tensor
state_dict = {name: tensor}
save_state_dict(state_dict, str(ckpt_file_path), use_safetensors)
# update the weight map
# * means all shards
ckpt_file_name_in_weight_map = 'dtensor/' + generate_dtensor_file_name(name, '*', use_safetensors)
index_file.append_weight_map(name, ckpt_file_name_in_weight_map)
def get_checkpoint_file_suffix(use_safetensors: bool) -> str:
"""
Get checkpoint file suffix.
Args:
use_safetensors (bool): whether to use safetensors to save the checkpoint.
Returns:
str: checkpoint file suffix.
"""
if use_safetensors:
return '.safetensors'
else:
return '.bin'
def generate_checkpoint_shard_file_name(index: int,
total_number: int,
use_safetensors: bool,
prefix: str = None) -> str:
"""
Generate checkpoint shard file name.
Args:
index (int): index of the shard.
total_number (int): total number of shards.
use_safetensors (bool): whether to use safetensors to save the checkpoint.
prefix (str): prefix of the shard file name. Default: None.
Returns:
str: checkpoint shard file name.
"""
suffix = get_checkpoint_file_suffix(use_safetensors)
if prefix is None:
return f"{index:05d}-of-{total_number:05d}.{suffix}"
else:
return f"{prefix}-{index:05d}-of-{total_number:05d}.{suffix}"
def generate_dtensor_file_name(param_name: str, index: int, use_safetensors: bool) -> str:
"""
Generate dtensor file name.
Args:
param_name (str): name of the distributed parameter.
index (int): index of the shard.
use_safetensors (bool): whether to use safetensors to save the checkpoint.
Returns:
str: dtensor file name.
"""
suffix = get_checkpoint_file_suffix(use_safetensors)
return f'{param_name}.{index}.{suffix}'
def save_state_dict_as_shard(
state_dict: dict,
checkpoint_path: str,
index: int,
total_number: int,
use_safetensors: bool,
prefix: str = None,
) -> None:
"""
Save state dict as shard.
Args:
state_dict (dict): state dict.
checkpoint_path (str): path to the checkpoint file.
index (int): index of the shard.
total_number (int): total number of shards.
prefix (str): prefix of the shard file name.
use_safetensors (bool): whether to use safetensors to save the checkpoint.
"""
# generate the shard name
shard_file_name = generate_checkpoint_shard_file_name(index, total_number, use_safetensors, prefix)
shard_file_path = Path(checkpoint_path).joinpath(shard_file_name).absolute()
# save the shard
save_state_dict(state_dict, str(shard_file_path), use_safetensors)
# ========================================
# Helper functions for loading state dict
# ========================================
def has_index_file(checkpoint_path: str) -> Tuple[bool, Optional[Path]]:
"""
Check whether the checkpoint has an index file.
Args:
checkpoint_path (str): path to the checkpoint.
Returns:
Tuple[bool, Optional[Path]]: a tuple of (has_index_file, index_file_path)
"""
checkpoint_path = Path(checkpoint_path)
if checkpoint_path.is_file():
# check if it is .index.json
reg = re.compile("(.*?).index((\..*)?).json")
if reg.fullmatch(checkpoint_path.name) is not None:
return True, checkpoint_path
else:
return False, None
elif checkpoint_path.is_dir():
# check if there is only one a file ending with .index.json in this directory
index_files = list(checkpoint_path.glob('*.index.*json'))
# if we found a .index.json file, make sure there is only one
if len(index_files) > 0:
assert len(
index_files
) == 1, f'Expected to find one .index.json file in {checkpoint_path}, but found {len(index_files)}'
if len(index_files) == 1:
return True, index_files[0]
else:
return False, None
else:
raise RuntimeError(f'Invalid checkpoint path {checkpoint_path}. Expected a file or a directory.')
def load_state_dict(checkpoint_file_path: Path):
"""
Load state dict from checkpoint.
Args:
checkpoint_file_path (Path): path to the checkpoint file.
Returns:
dict: state dict.
"""
assert not is_dtensor_checkpoint(checkpoint_file_path), \
f'Cannot load state dict from dtensor checkpoint {checkpoint_file_path}, you should convert the distributed tensors to gathered tensors with our CLI offline.'
if is_safetensor_checkpoint(checkpoint_file_path):
assert is_safetensors_available(), \
f'Cannot load state dict from safetensor checkpoint {checkpoint_file_path}, because safetensors is not available. Please install safetensors first with pip install safetensors.'
# load with safetensors
from safetensors import safe_open
state_dict = {}
with safe_open(checkpoint_file_path, framework="pt", device="cpu") as f:
for k in f.keys():
state_dict[k] = f.get_tensor(k)
return state_dict
else:
# load with torch
return torch.load(checkpoint_file_path)
def add_variant(weights_name: str, variant: Optional[str] = None) -> str:
if variant is not None and len(variant) > 0:
splits = weights_name.split(".")
splits = splits[:-1] + [variant] + splits[-1:]
weights_name = ".".join(splits)
return weights_name
def get_base_filenames(variant: str = None, use_safetensors: bool = False):
"""
generate base weight filenames
"""
weights_name = SAFE_WEIGHTS_NAME if use_safetensors else WEIGHTS_NAME
weights_name = add_variant(weights_name, variant)
save_index_file = SAFE_WEIGHTS_INDEX_NAME if use_safetensors else WEIGHTS_INDEX_NAME
save_index_file = add_variant(save_index_file, variant)
return weights_name, save_index_file
def get_shard_filename(weights_name: str, idx: int):
"""
get shard file name
"""
shard_file = weights_name.replace(".bin", f"-{idx+1:05d}.bin")
shard_file = shard_file.replace(".safetensors", f"-{idx + 1:05d}.safetensors")
return shard_file