Files
LLaMA-Factory/src/llmtuner/tuner/core/trainer.py
2023-08-02 18:46:41 +08:00

96 lines
4.0 KiB
Python

import os
import torch
from typing import TYPE_CHECKING, Dict, Optional
from transformers import Seq2SeqTrainer
from transformers.trainer import TRAINING_ARGS_NAME, WEIGHTS_NAME
from transformers.modeling_utils import PreTrainedModel, unwrap_model
from peft import PeftModel
from trl import PreTrainedModelWrapper
from llmtuner.extras.constants import FINETUNING_ARGS_NAME, VALUE_HEAD_FILE_NAME
from llmtuner.extras.logging import get_logger
from llmtuner.extras.save_and_load import get_state_dict, load_trainable_params
if TYPE_CHECKING:
from llmtuner.hparams import FinetuningArguments
logger = get_logger(__name__)
class PeftTrainer(Seq2SeqTrainer):
r"""
Inherits Seq2SeqTrainer to support parameter-efficient checkpoints.
"""
def __init__(self, finetuning_args: "FinetuningArguments", **kwargs):
super().__init__(**kwargs)
self.finetuning_args = finetuning_args
self._remove_log()
def _remove_log(self):
if self.is_world_process_zero() and os.path.exists(os.path.join(self.args.output_dir, "trainer_log.jsonl")):
logger.warning("Previous log file in this folder will be deleted.")
os.remove(os.path.join(self.args.output_dir, "trainer_log.jsonl"))
def _save(self, output_dir: Optional[str] = None, state_dict: Optional[Dict[str, torch.Tensor]] = None) -> None:
r"""
Saves trainable parameters as model checkpoint.
This function will only be executed at the process zero.
Subclass and override to inject custom behavior. It should not be directly used by external scripts.
"""
output_dir = output_dir if output_dir is not None else self.args.output_dir
os.makedirs(output_dir, exist_ok=True)
logger.info(f"Saving model checkpoint to {output_dir}")
model = unwrap_model(self.model)
if isinstance(model, PreTrainedModelWrapper):
# Custom state dict: https://github.com/lvwerra/trl/blob/v0.4.7/trl/models/modeling_value_head.py#L200
model_state_dict = state_dict or model.state_dict()
v_head_state_dict = {
name.replace("v_head.", ""): model_state_dict[name].cpu().clone().detach()
for name in model_state_dict.keys() if name.startswith("v_head.")
}
torch.save(v_head_state_dict, os.path.join(output_dir, VALUE_HEAD_FILE_NAME))
model = model.pretrained_model
state_dict = state_dict or get_state_dict(model)
if isinstance(model, (PeftModel, PreTrainedModel)):
model.config.use_cache = True
model.save_pretrained(output_dir, state_dict=state_dict, safe_serialization=self.args.save_safetensors)
model.config.use_cache = False
else:
torch.save(state_dict, os.path.join(output_dir, WEIGHTS_NAME))
if self.finetuning_args.finetuning_type == "full" and self.tokenizer is not None:
self.tokenizer.save_pretrained(output_dir)
with open(os.path.join(output_dir, TRAINING_ARGS_NAME), "w", encoding="utf-8") as f:
f.write(self.args.to_json_string() + "\n")
self.finetuning_args.save_to_json(os.path.join(output_dir, FINETUNING_ARGS_NAME))
def _load_best_model(self):
r"""
Loads trainable parameters from model checkpoint.
Subclass and override to inject custom behavior. It should not be directly used by external scripts.
"""
logger.info(f"Loading best model from {self.state.best_model_checkpoint} (score: {self.state.best_metric}).")
model = unwrap_model(self.model)
if isinstance(model, PreTrainedModelWrapper):
model.v_head.load_state_dict(torch.load(
os.path.join(self.state.best_model_checkpoint, VALUE_HEAD_FILE_NAME), map_location="cpu"
))
model = model.pretrained_model
if isinstance(model, PeftModel):
model.load_adapter(self.state.best_model_checkpoint, model.active_adapter)
else: # freeze/full-tuning
load_trainable_params(model, self.state.best_model_checkpoint)