ColossalAI/colossalai/interface/model.py

137 lines
4.9 KiB
Python

import re
from typing import Dict, Set
import torch
import torch.nn as nn
from peft import PeftModel, PeftType
def extract_lora_layers(model: PeftModel, names: Set[str], adapter_name: str = "default"):
config = model.peft_config[adapter_name]
if config.peft_type != PeftType.LORA:
raise ValueError(f"Adapter {adapter_name} is not a LORA adapter.")
# to_return = lora_state_dict(model, bias=model.peft_config.bias)
# adapted from `https://github.com/microsoft/LoRA/blob/main/loralib/utils.py`
# to be used directly with the state dict which is necessary when using DeepSpeed or FSDP
bias = config.bias
if bias == "none":
to_return = {k for k in names if "lora_" in k}
elif bias == "all":
to_return = {k for k in names if "lora_" in k or "bias" in k}
elif bias == "lora_only":
to_return = set()
for k in names:
if "lora_" in k:
to_return.add(k)
bias_name = k.split("lora_")[0] + "bias"
if bias_name in names:
to_return.add(bias_name)
else:
raise NotImplementedError
to_return = {k for k in to_return if (("lora_" in k and adapter_name in k) or ("bias" in k))}
if config.use_dora:
# Here we take care of a refactor of DoRA which changed lora_magnitude_vector from a ParameterDict to a
# ModuleDict with a DoraLayer instance. The old parameter is now the "weight" attribute of that layer. Since
# we want the state_dict format not to change, we remove the "weight" part.
new_dora_suffix = f"lora_magnitude_vector.{adapter_name}.weight"
def renamed_dora_weights(k):
if k.endswith(new_dora_suffix):
k = k[:-7] # remove ".weight"
return k
to_return = {renamed_dora_weights(k) for k in to_return}
to_return = {re.sub(f"lora_\S\.{adapter_name}\.(weight|bias)", "base_layer", k) for k in to_return}
return to_return
class PeftUnwrapMixin:
def __init__(self, peft_model: PeftModel):
self.base_model = peft_model.get_base_model()
# peft does not affect buffers
self.lora_layers = extract_lora_layers(peft_model, set(n for n, p in self.base_model.named_parameters()))
potential_lora_weights = set()
for n in self.lora_layers:
potential_lora_weights.add(f"{n}.weight")
potential_lora_weights.add(f"{n}.bias")
self.lora_param_to_origin_param = {n: n.replace("base_layer.", "") for n in potential_lora_weights}
self.origin_param_to_lora_param = {v: k for k, v in self.lora_param_to_origin_param.items()}
def named_parameters(self):
for n, p in self.base_model.named_parameters():
if n in self.lora_param_to_origin_param:
n = self.lora_param_to_origin_param[n]
yield n, p
def named_buffers(self):
return self.base_model.named_buffers()
@property
def _modules(self):
return self.base_model._modules
@property
def _non_persistent_buffers_set(self):
return self.base_model._non_persistent_buffers_set
def patch_state_dict(self, state_dict: Dict[str, torch.Tensor]):
new_state_dict = {}
for k, v in state_dict.items():
if k in self.origin_param_to_lora_param:
k = self.origin_param_to_lora_param[k]
new_state_dict[k] = v
return new_state_dict
def state_dict(self):
state_dict = {}
for k, v in self.base_model.state_dict().items():
if k in self.lora_param_to_origin_param:
k = self.lora_param_to_origin_param[k]
state_dict[k] = v
return state_dict
def load_state_dict(self, state_dict, strict: bool = True, assign: bool = False):
state_dict = self.patch_state_dict(state_dict)
self.base_model.load_state_dict(state_dict, strict=strict, assign=assign)
def __hash__(self):
return hash(self.base_model)
class ModelWrapper(nn.Module):
"""
A wrapper class to define the common interface used by booster.
Args:
module (nn.Module): The model to be wrapped.
"""
def __init__(self, module: nn.Module) -> None:
super().__init__()
self.module = module
def unwrap(self, unwrap_peft: bool = True):
"""
Unwrap the model to return the original model for checkpoint saving/loading.
"""
if isinstance(self.module, ModelWrapper):
model = self.module.unwrap()
else:
model = self.module
if unwrap_peft and isinstance(model, PeftModel):
model = PeftUnwrapMixin(model)
return model
def forward(self, *args, **kwargs):
return self.module(*args, **kwargs)
class AMPModelMixin:
"""This mixin class defines the interface for AMP training."""
def update_master_params(self):
"""
Update the master parameters for AMP training.
"""