ColossalAI/colossalai/booster/plugin/low_level_zero_plugin.py

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import enum
import logging
import os
import warnings
from functools import partial
from pathlib import Path
from types import MethodType
from typing import Callable, Dict, Iterator, List, Optional, Tuple
import torch
import torch.nn as nn
from torch.nn import Parameter
from torch.optim import Optimizer
from torch.optim.lr_scheduler import _LRScheduler as LRScheduler
from torch.utils._pytree import tree_map
from torch.utils.data import DataLoader
from colossalai.accelerator import get_accelerator
from colossalai.checkpoint_io import CheckpointIndexFile, CheckpointIO
from colossalai.checkpoint_io.utils import (
get_optimizer_base_filenames,
get_shard_filename,
load_param_groups_into_optimizer,
load_shard_state_dict,
load_states_into_optimizer,
save_param_groups,
save_state_dict,
sharded_optimizer_loading_epilogue,
)
from colossalai.interface import AMPModelMixin, ModelWrapper, OptimizerWrapper
from colossalai.quantization import BnbQuantizationConfig, quantize_model
from colossalai.zero import LowLevelZeroOptimizer
from .dp_plugin_base import DPPluginBase
from .torch_ddp_plugin import TorchDDPCheckpointIO
__all__ = ["LowLevelZeroPlugin"]
def _convert_floating_point(x, dtype: torch.dtype = torch.float16):
if isinstance(x, torch.Tensor) and torch.is_floating_point(x):
return x.to(dtype)
return x
SUPPORTED_PRECISION = ["fp16", "bf16", "fp32"]
class OptimizerParamCheckState(enum.Enum):
ORIGIN_PARAM_FINDED = 0
ORIGIN_PARAM_NOT_FIND = -1
LORA_PARM_EXISTED = -2
class LowLevelZeroModel(ModelWrapper, AMPModelMixin):
def __init__(self, module: nn.Module, precision: str) -> None:
super().__init__(module)
self.dtype = None
if precision == "fp16":
self.dtype = torch.float16
elif precision == "bf16":
self.dtype = torch.bfloat16
if self.dtype is not None:
module = module.to(self.dtype)
module = module.to(get_accelerator().get_current_device())
self.module = module
self.convert_fn = None
if self.dtype is not None:
self.convert_fn = partial(_convert_floating_point, dtype=self.dtype)
def forward(self, *args, **kwargs):
if self.convert_fn is not None:
args = tree_map(self.convert_fn, args)
kwargs = tree_map(self.convert_fn, kwargs)
return super().forward(*args, **kwargs)
class LowLevelZeroCheckpointIO(TorchDDPCheckpointIO):
def save_unsharded_optimizer(self, optimizer: OptimizerWrapper, checkpoint: str, gather_dtensor: bool = False):
"""Save optimizer to checkpoint but only on master process.
Args:
optimizer (OptimizerWrapper): Optimizer to save state_dict
checkpoint (str): Path to save checkpoint
gather_dtensor (bool): Whether to gather_dtensor, not used
"""
assert isinstance(optimizer, LowLevelZeroOptimizer), "Please boost the optimizer before saving!"
# the `state_dict` in LowLevelZeroOptimizer has communication
# if only the master rank collect state_dict and save,
# the communication on each rank would not match
state_dict = optimizer.state_dict()
if self.coordinator.is_master():
save_state_dict(state_dict, checkpoint, use_safetensors=False)
def save_sharded_optimizer(
self,
optimizer: OptimizerWrapper,
checkpoint: str,
gather_dtensor: bool = False,
prefix: str = None,
size_per_shard: int = 1024,
):
"""
Save sharded Zero-optimizer checkpoint under the given checkpointing path.
The following files will be created under the path:
- An index file (pytorch_optim.bin.index.json) containing a map between optimizer states and file names
- A group file (pytorch_optim_group.bin) recording information of param_groups
- Multiple files (pytorch_optim-000XX.bin) that store state tensors of optimizer in a sharding way
Args:
optimizer (OptimizerWrapper): Optimizer to save sharded state_dict
checkpoint (str): Path to save optimizer state_dict
gather_dtensor (bool): Whether to gather_dtensor, not used
prefix (str): Perfix of file to save
size_per_shard (int): Max file size of each file that store state tensors
"""
assert isinstance(optimizer, LowLevelZeroOptimizer), "Please boost the optimizer before saving!"
if os.path.isfile(checkpoint):
logging.error(f"Provided path ({checkpoint}) should be a directory, not a file")
return
Path(checkpoint).mkdir(parents=True, exist_ok=True)
# state_dict only provide only 'param_groups'
state_dict = optimizer.optim.state_dict()
# state shard would be handled by the low-level zero optimizer
sharded_state = optimizer.state_dict_shard(max_shard_size=size_per_shard)
# Preparing file paths and index file.
states_name, save_index_file, param_group_file = get_optimizer_base_filenames(prefix)
index_file = CheckpointIndexFile(checkpoint)
index_file.append_meta_data("param_groups", param_group_file)
# Store the information of param groups to param_group_file.
if self.coordinator.is_master():
group_file_path = os.path.join(checkpoint, param_group_file)
save_param_groups(state_dict, group_file_path)
# Save shards of optimizer states.
total_size = 0
for idx, shard_pair in enumerate(sharded_state):
shard, current_size = shard_pair
shard_file = get_shard_filename(states_name, idx)
total_size = total_size + current_size
for param_id in shard.keys():
index_file.append_weight_map(str(param_id), shard_file)
checkpoint_file_path = os.path.join(checkpoint, shard_file)
if self.coordinator.is_master():
save_state_dict(shard, checkpoint_file_path, use_safetensors=False)
# Wrap up index file.
index_file.append_meta_data("total_size", total_size)
if self.coordinator.is_master():
index_file.write_index_file(save_index_file)
logging.info(
f"The optimizer is going to be split to checkpoint shards. "
f"You can find where each parameters has been saved in the "
f"index located at {save_index_file}."
)
def load_sharded_optimizer(self, optimizer: OptimizerWrapper, index_file_path: str, prefix: str):
"""Load sharded optimizer with the given path to index file.
Args:
optimizer (OptimizerWrapper): Optimizer to load state_dict
index_file_path (str): Path to the index file
prefix (str): Not used.
"""
assert isinstance(optimizer, LowLevelZeroOptimizer), "Please boost the optimizer before Loading!"
optimizer = optimizer.unwrap()
# Read checkpoint index file.
ckpt_index_file = CheckpointIndexFile.from_file(index_file_path)
# Load param_groups
param_group_path = ckpt_index_file.get_param_group_filename()
if param_group_path is None:
raise RuntimeError(
f"Invalid index file path {index_file_path} for an optimizer. \
Lacking param group file under current directory."
)
id_map = load_param_groups_into_optimizer(optimizer, param_group_path)
checkpoint_files, _ = ckpt_index_file.get_checkpoint_filenames()
for shard_file in checkpoint_files:
state_dict = load_shard_state_dict(Path(shard_file), use_safetensors=False)
# shard state dict
for param_idx, state in state_dict.items():
for k, v in state.items():
if isinstance(v, torch.Tensor) and k != "step":
padding_size = (
self.coordinator.world_size - v.numel() % self.coordinator.world_size
) % self.coordinator.world_size
with torch.no_grad():
v = v.flatten()
if padding_size > 0:
v = torch.nn.functional.pad(v, [0, padding_size])
v_list = v.split(v.numel() // self.coordinator.world_size)
state_dict[param_idx][k] = v_list[self.coordinator.rank].detach().clone()
load_states_into_optimizer(optimizer, state_dict, id_map)
sharded_optimizer_loading_epilogue(optimizer)
def load_unsharded_model(self, model: ModelWrapper, checkpoint: str, strict: bool = True):
assert isinstance(model, LowLevelZeroModel), "Please boost the model before loading!"
super().load_unsharded_model(model, checkpoint, strict)
model.update_master_params()
def load_sharded_model(
self,
model: ModelWrapper,
checkpoint_index_file: Path,
strict: bool = False,
use_safetensors: bool = False,
load_sub_module: bool = True,
):
assert isinstance(model, LowLevelZeroModel), "Please boost the model before loading!"
super().load_sharded_model(model, checkpoint_index_file, strict, use_safetensors, load_sub_module)
model.update_master_params()
def save_lora_as_pretrained(self, model, checkpoint, use_safetensors):
if os.path.isfile(checkpoint):
logging.error(f"Provided path ({checkpoint}) should be a directory, not a file")
return
from peft import PeftModel
assert isinstance(model, ModelWrapper), "Please boost the model before saving!"
peft_model = model.unwrap()
assert isinstance(
peft_model, PeftModel
), "The model doesn't have lora adapters, please enable lora before saving."
return peft_model.save_pretrained(checkpoint, safe_serialization=use_safetensors)
class LowLevelZeroPlugin(DPPluginBase):
"""
Plugin for low level zero.
```python
from colossalai.booster import Booster
from colossalai.booster.plugin import LowLevelZeroPlugin
model, train_dataset, optimizer, criterion = ...
plugin = LowLevelZeroPlugin()
train_dataloader = plugin.prepare_dataloader(train_dataset, batch_size=8)
booster = Booster(plugin=plugin)
model, optimizer, train_dataloader, criterion = booster.boost(model, optimizer, train_dataloader, criterion)
```
Args:
stage (int, optional): ZeRO stage. Defaults to 1.
precision (str, optional): precision. Support 'fp16', 'bf16' and 'fp32'. Defaults to 'fp16'.
initial_scale (float, optional): Initial scale used by DynamicGradScaler. Defaults to 2**32.
min_scale (float, optional): Min scale used by DynamicGradScaler. Defaults to 1.
growth_factor (float, optional): growth_factor used by DynamicGradScaler. Defaults to 2.
backoff_factor (float, optional): backoff_factor used by DynamicGradScaler. Defaults to 0.5.
growth_interval (float, optional): growth_interval used by DynamicGradScaler. Defaults to 1000.
hysteresis (float, optional): hysteresis used by DynamicGradScaler. Defaults to 2.
max_scale (int, optional): max_scale used by DynamicGradScaler. Defaults to 2**32.
max_norm (float, optional): max_norm used for `clip_grad_norm`. You should notice that you shall not do
clip_grad_norm by yourself when using ZeRO DDP. The ZeRO optimizer will take care of clip_grad_norm.
norm_type (float, optional): norm_type used for `clip_grad_norm`.
reduce_bucket_size_in_m (int, optional): grad reduce bucket size in M. Defaults to 12.
communication_dtype (torch.dtype, optional): communication dtype. If not specified, the dtype of param will be used. Defaults to None.
overlap_communication (bool, optional): whether to overlap communication and computation. Defaults to True.
cpu_offload (bool, optional): whether to offload grad, master weight and optimizer state to cpu. Defaults to False.
verbose (bool, optional): verbose mode. Debug info including grad overflow will be printed. Defaults to False.
"""
def __init__(
self,
stage: int = 1,
precision: str = "fp16",
initial_scale: float = 2**32,
min_scale: float = 1,
growth_factor: float = 2,
backoff_factor: float = 0.5,
growth_interval: int = 1000,
hysteresis: int = 2,
max_scale: float = 2**32,
max_norm: float = 0.0,
norm_type: float = 2.0,
reduce_bucket_size_in_m: int = 12,
communication_dtype: Optional[torch.dtype] = None,
overlap_communication: bool = True,
cpu_offload: bool = False,
master_weights: bool = True,
verbose: bool = False,
) -> None:
super().__init__()
assert stage in (1, 2), f"LowLevelZeroPlugin only supports stage 1/2 training"
assert precision in SUPPORTED_PRECISION, f"LowLevelZeroPlugin only supports {SUPPORTED_PRECISION} training"
assert norm_type == 2.0, f"LowLevelZeroPlugin only supports norm_type=2.0 now"
self.stage = stage
self.precision = precision
self.zero_optim_kwargs = dict(
initial_scale=initial_scale,
min_scale=min_scale,
growth_factor=growth_factor,
backoff_factor=backoff_factor,
growth_interval=growth_interval,
hysteresis=hysteresis,
max_scale=max_scale,
clip_grad_norm=max_norm,
reduce_bucket_size=reduce_bucket_size_in_m * 1024 * 1024,
communication_dtype=communication_dtype,
overlap_communication=overlap_communication,
partition_grad=(stage == 2),
cpu_offload=cpu_offload,
master_weights=master_weights,
)
self.lora_enabled = False
self.verbose = verbose
# set class name with stage, for better error message
setattr(self.__class__, "__name__", f"LowLevelZeroPlugin_ZeRO-{stage}")
def support_no_sync(self) -> bool:
return self.stage == 1
def support_lora(self) -> bool:
return False
def control_precision(self) -> bool:
return True
def supported_precisions(self) -> List[str]:
return SUPPORTED_PRECISION
def control_device(self) -> bool:
return True
def supported_devices(self) -> List[str]:
return ["cuda", "npu"]
def support_lora(self) -> bool:
return True
def enable_lora(
self,
model: nn.Module,
pretrained_dir: Optional[str] = None,
lora_config: Optional[Dict] = None,
bnb_quantization_config: Optional[BnbQuantizationConfig] = None,
) -> nn.Module:
from peft import PeftModel, get_peft_model
assert not isinstance(model, LowLevelZeroModel), "Lora should be enabled before boosting the model."
self.lora_enabled = True
warnings.warn("You have enabled LoRa training. Please check the hyperparameters such as lr")
if bnb_quantization_config is not None:
model = quantize_model(model, bnb_quantization_config)
if pretrained_dir is None:
peft_model = get_peft_model(model, lora_config)
else:
peft_model = PeftModel.from_pretrained(model, pretrained_dir, is_trainable=True)
return peft_model
def get_param_group_id(self, optimizer: Optimizer, origin_param: Parameter):
origin_param_id = id(origin_param)
for group_id, param_group in enumerate(optimizer.param_groups):
for p in param_group["params"]:
if id(p) == origin_param_id:
return group_id
return -1
def get_param_group_id(self, optimizer: Optimizer, origin_param: Parameter, lora_param: Parameter):
origin_param_id = id(origin_param)
lora_param_id = id(lora_param)
target_group_id = None
for group_id, param_group in enumerate(optimizer.param_groups):
for p in param_group["params"]:
if id(p) == lora_param_id:
# check if the lora parameter exists.
return target_group_id, OptimizerParamCheckState.LORA_PARM_EXISTED
if id(p) == origin_param_id:
target_group_id = group_id
if target_group_id is not None:
return target_group_id, OptimizerParamCheckState.ORIGIN_PARAM_FINDED
else:
return target_group_id, OptimizerParamCheckState.ORIGIN_PARAM_NOT_FIND
def add_lora_params_to_optimizer(self, model, optimizer):
"""add lora parameters to optimizer"""
name2param = {}
for name, param in model.named_parameters():
name2param[name] = param
for name, param in name2param.items():
if "lora_A" in name or "lora_B" in name:
origin_key = name.replace("lora_A.", "")
origin_key = origin_key.replace("lora_B.", "")
origin_key = origin_key.replace(f"{model.active_adapter}", "base_layer")
origin_param = name2param[origin_key]
group_id, check_state = self.get_param_group_id(optimizer, origin_param, param)
if check_state == OptimizerParamCheckState.ORIGIN_PARAM_NOT_FIND:
warnings.warn(
"Origin parameter {origin_key} related to {name} doesn't exist in optimizer param_groups."
)
elif (
check_state == OptimizerParamCheckState.ORIGIN_PARAM_FINDED
and group_id is not None
and group_id >= 0
):
optimizer.param_groups[group_id]["params"].append(param)
def configure(
self,
model: nn.Module,
optimizer: Optional[Optimizer] = None,
criterion: Optional[Callable] = None,
dataloader: Optional[DataLoader] = None,
lr_scheduler: Optional[LRScheduler] = None,
) -> Tuple[nn.Module, OptimizerWrapper, Callable, DataLoader, LRScheduler]:
if self.lora_enabled:
from peft import PeftModel
assert isinstance(
model, PeftModel
), "The model should have been wrapped as a PeftModel when self.lora_enabled is True"
if optimizer is not None:
self.add_lora_params_to_optimizer(model, optimizer)
if not isinstance(model, ModelWrapper):
model = LowLevelZeroModel(model, self.precision)
if optimizer is not None and not isinstance(optimizer, OptimizerWrapper):
optimizer: LowLevelZeroOptimizer = LowLevelZeroOptimizer(
optimizer, **self.zero_optim_kwargs, verbose=self.verbose
)
# inject update_master_params
model.update_master_params = MethodType(optimizer.update_master_params, model)
return model, optimizer, criterion, dataloader, lr_scheduler
def control_checkpoint_io(self) -> bool:
return True
def get_checkpoint_io(self) -> CheckpointIO:
return LowLevelZeroCheckpointIO()
def no_sync(self, model: nn.Module, optimizer: OptimizerWrapper) -> Iterator[None]:
assert isinstance(optimizer, LowLevelZeroOptimizer)
return optimizer.no_sync()