refactor train.py

This commit is contained in:
Dan Saunders
2025-02-26 19:37:42 +00:00
parent 75cbd15301
commit c4104fc10c

View File

@@ -6,15 +6,15 @@ import signal
import sys
import weakref
from pathlib import Path
from typing import Tuple, Union
from typing import Any, Tuple, Union
import torch
import transformers.modelcard
from accelerate.logging import get_logger
from accelerate.utils import save_fsdp_model
from peft import PeftModel
from peft import PeftConfig, PeftModel
from pkg_resources import get_distribution # type: ignore
from transformers import PreTrainedModel, PreTrainedTokenizer
from transformers import PreTrainedModel, PreTrainedTokenizer, ProcessorMixin
from transformers.integrations.deepspeed import is_deepspeed_zero3_enabled
from axolotl.common.datasets import TrainDatasetMeta
@@ -27,11 +27,13 @@ from axolotl.utils.freeze import freeze_layers_except
from axolotl.utils.models import load_model, load_processor, load_tokenizer
from axolotl.utils.trainer import setup_trainer
# Optional imports with graceful fallbacks
try:
from optimum.bettertransformer import BetterTransformer
except ImportError:
BetterTransformer = None
# Project setup
project_root = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))
src_dir = os.path.join(project_root, "src")
sys.path.insert(0, src_dir)
@@ -40,9 +42,20 @@ configure_logging()
LOG = get_logger(__name__)
def train(
*, cfg: DictDefault, dataset_meta: TrainDatasetMeta
) -> Tuple[Union[PeftModel, PreTrainedModel], PreTrainedTokenizer]:
def setup_model_and_tokenizer(
cfg: DictDefault,
) -> Tuple[
PreTrainedTokenizer, ProcessorMixin | None, PreTrainedModel, PeftConfig | None
]:
"""
Load the tokenizer, processor (for multimodal models), and model based on configuration.
Args:
cfg: The configuration dictionary with training parameters
Returns:
Tuple containing tokenizer, processor (if multimodal, else None), model, and peft_config (if applicable, else None)
"""
# Load tokenizer
LOG.debug(
f"loading tokenizer... {cfg.tokenizer_config or cfg.base_model_config}",
@@ -55,11 +68,58 @@ def train(
if cfg.is_multimodal:
processor = load_processor(cfg, tokenizer)
# Get datasets
train_dataset = dataset_meta.train_dataset
eval_dataset = dataset_meta.eval_dataset
total_num_steps = dataset_meta.total_num_steps
# Load the model and peft_config
msg = "loading model"
if cfg.adapter:
msg += " and peft_config..."
LOG.debug(msg)
model, peft_config = load_model(cfg, tokenizer, processor=processor)
if model.generation_config is not None:
model.generation_config.do_sample = True
# Apply freezing if specified
if cfg.unfrozen_parameters:
freeze_layers_except(model, cfg.unfrozen_parameters)
return tokenizer, processor, model, peft_config
def setup_reference_model(
cfg: DictDefault, tokenizer: PreTrainedTokenizer
) -> PreTrainedModel | None:
"""
Set up the reference model for RL training if needed.
Args:
cfg: The configuration dictionary
tokenizer: The tokenizer to use for the reference model
Returns:
Reference model if needed for RL training, None otherwise
"""
model_ref = None
if cfg.rl and cfg.rl != "orpo":
if cfg.adapter and not cfg.rl_adapter_ref_model:
# use built-in trl autounwrap
LOG.debug("Passing model_ref: None to RL trainer")
model_ref = None # explicit setting to None
else:
# load the model again for model_ref/baseline
model_ref, _ = load_model(cfg, tokenizer, reference_model=True)
return model_ref
def determine_resume_checkpoint(cfg: DictDefault) -> str | None:
"""
Determine the checkpoint to resume from based on configuration.
Args:
cfg: The configuration dictionary
Returns:
Path to the checkpoint to resume from, or None if not resuming
"""
if cfg.resume_from_checkpoint is None and cfg.auto_resume_from_checkpoints:
possible_checkpoints = [
str(cp) for cp in Path(cfg.output_dir).glob("checkpoint-*")
@@ -73,77 +133,22 @@ def train(
LOG.info(
f"Using Auto-resume functionality to start with checkpoint at {cfg.resume_from_checkpoint}"
)
resume_from_checkpoint = cfg.resume_from_checkpoint
return cfg.resume_from_checkpoint
# Load the model and tokenizer
msg = "loading model"
if cfg.adapter:
msg += " and peft_config..."
LOG.debug(msg)
model, peft_config = load_model(cfg, tokenizer, processor=processor)
if model.generation_config is not None:
model.generation_config.do_sample = True
model_ref = None
if cfg.rl and cfg.rl != "orpo":
if cfg.adapter and not cfg.rl_adapter_ref_model:
# use built-in trl autounwrap
LOG.debug("Passing model_ref: None to RL trainer")
model_ref = None # explicit setting to None
else:
# load the model again for model_ref/baseline
model_ref, _ = load_model(cfg, tokenizer, reference_model=True)
def setup_signal_handler(
cfg: DictDefault, model: PreTrainedModel, safe_serialization: bool
):
"""
Set up signal handler for graceful termination.
safe_serialization = cfg.save_safetensors is True
if cfg.unfrozen_parameters:
freeze_layers_except(model, cfg.unfrozen_parameters)
trainer = setup_trainer(
cfg,
train_dataset,
eval_dataset,
(model, model_ref, peft_config),
tokenizer,
processor,
total_num_steps,
)
if cfg.fix_untrained_tokens:
# check if the `token_ids_to_fix` kwarg exists in the fix_untrained_tokens args
sig = inspect.signature(fix_untrained_tokens)
# if the function has the `token_ids_to_fix` arg, and fix_untrained_tokens is a list
if "token_ids_to_fix" in sig.parameters and isinstance(
cfg.fix_untrained_tokens, list
):
fix_untrained_tokens(
model,
tokenizer,
train_dataset,
token_ids_to_fix=cfg.fix_untrained_tokens,
)
else:
fix_untrained_tokens(model, tokenizer, train_dataset)
if cfg.local_rank == 0:
model.save_pretrained(
str(Path(cfg.output_dir)), safe_serialization=safe_serialization
)
# go ahead and presave, so we have the adapter config available to inspect
if peft_config:
LOG.info(f"Pre-saving adapter config to {cfg.output_dir}")
peft_config.save_pretrained(cfg.output_dir)
# additionally presave the tokenizer and model configs
if not Path(cfg.output_dir).is_dir():
os.makedirs(cfg.output_dir, exist_ok=True)
tokenizer.save_pretrained(str(Path(cfg.output_dir)))
if hasattr(model, "config"):
model.config.save_pretrained(str(Path(cfg.output_dir)))
# In case we want to stop early with ctrl+c, this is a nice to have to save the pretrained model
if (
cfg.local_rank == 0 and not cfg.use_ray
): # ray workers don't have access to this signal
Args:
cfg: The configuration dictionary
model: The model to save on termination
safe_serialization: Whether to use safe serialization when saving
"""
# ray workers don't have access to this signal
if cfg.local_rank == 0 and not cfg.use_ray:
def terminate_handler(_, __, model_weakref):
if model_weakref() is not None:
@@ -161,21 +166,22 @@ def train(
lambda signum, frame: terminate_handler(signum, frame, _model_weakref),
)
badge_markdown = """[<img src="https://raw.githubusercontent.com/axolotl-ai-cloud/axolotl/main/image/axolotl-badge-web.png" alt="Built with Axolotl" width="200" height="32"/>](https://github.com/axolotl-ai-cloud/axolotl)"""
transformers.modelcard.AUTOGENERATED_TRAINER_COMMENT += f"\n{badge_markdown}"
if getattr(cfg, "axolotl_config_path"):
raw_axolotl_cfg = Path(cfg.axolotl_config_path)
version = get_distribution("axolotl").version
if raw_axolotl_cfg.is_file():
transformers.modelcard.AUTOGENERATED_TRAINER_COMMENT += f"\n<details><summary>See axolotl config</summary>\n\naxolotl version: `{version}`\n```yaml\n{raw_axolotl_cfg.read_text(encoding='utf-8')}\n```\n\n</details><br>\n"
def execute_training(
cfg: DictDefault, trainer: Any, resume_from_checkpoint: str | None
):
"""
Execute the training process with appropriate backend configurations.
Args:
cfg: The configuration dictionary
trainer: The configured trainer object
resume_from_checkpoint: Path to checkpoint to resume from, if applicable
"""
LOG.info("Starting trainer...")
if cfg.group_by_length:
LOG.info("hang tight... sorting dataset for group_by_length")
pretrain_hooks(cfg, trainer)
if cfg.flash_optimum:
with torch.backends.cuda.sdp_kernel(
# TODO configure these from the YAML w/ sdp_kernel_kwargs: ...
@@ -187,15 +193,30 @@ def train(
else:
trainer.train(resume_from_checkpoint=resume_from_checkpoint)
post_train_hooks(cfg, trainer)
def save_trained_model(
cfg: DictDefault,
trainer: Any,
model: PreTrainedModel,
safe_serialization: bool,
):
"""
Save the trained model according to configuration and training setup.
Args:
cfg: The configuration dictionary
trainer: The trainer object
model: The trained model to save
safe_serialization: Whether to use safe serialization
"""
LOG.info(f"Training Completed!!! Saving pre-trained model to {cfg.output_dir}")
# post training
# Post training module hooks
for name, module in model.named_modules():
if hasattr(module, "_post_training"):
module._post_training(model, name) # pylint: disable=protected-access
# Handle FSDP state dict type
state_dict_type = "FULL_STATE_DICT"
if trainer.is_fsdp_enabled:
if cfg.fsdp_final_state_dict_type:
@@ -203,12 +224,13 @@ def train(
trainer.accelerator.state.fsdp_plugin.set_state_dict_type(state_dict_type)
LOG.info(f"Set FSDP state dict type to {state_dict_type} for saving.")
# Handle ReLoRA early return case
if cfg.relora_steps:
if cfg.adapter == "lora" and not (cfg.load_in_4bit or cfg.load_in_8bit):
model = model.merge_and_unload()
else:
# final model weights have already been saved by `ReLoRACallback.on_train_end`
return model, tokenizer
return
# TODO do we need this fix? https://huggingface.co/docs/accelerate/usage_guides/fsdp#saving-and-loading
# only save on rank 0, otherwise it corrupts output on multi-GPU when multiple processes attempt to write the same file
@@ -255,6 +277,15 @@ def train(
)
model.save_pretrained(cfg.output_dir, safe_serialization=safe_serialization)
def create_model_card(cfg: DictDefault, trainer: Any):
"""
Create a model card for the trained model if needed.
Args:
cfg: The configuration dictionary
trainer: The trainer object with model card creation capabilities
"""
if not cfg.hub_model_id:
try:
model_card_kwarg = {
@@ -291,22 +322,162 @@ def train(
# defensively push to the hub to ensure the model card is updated
trainer.push_to_hub()
def save_initial_configs(
cfg: DictDefault,
tokenizer: PreTrainedTokenizer,
model: PreTrainedModel,
peft_config: PeftConfig | None,
):
"""
Save initial configurations before training.
Args:
cfg: The configuration dictionary
tokenizer: The tokenizer to save
model: The model to save configuration for
peft_config: The PEFT configuration to save if applicable
"""
# go ahead and presave, so we have the adapter config available to inspect
if peft_config:
LOG.info(f"Pre-saving adapter config to {cfg.output_dir}")
peft_config.save_pretrained(cfg.output_dir)
# additionally presave the tokenizer and model configs
output_dir = Path(cfg.output_dir)
if not output_dir.is_dir():
os.makedirs(cfg.output_dir, exist_ok=True)
tokenizer.save_pretrained(str(output_dir))
if hasattr(model, "config"):
model.config.save_pretrained(str(output_dir))
def setup_badge_for_model_card():
"""Set up the Axolotl badge for the model card."""
badge_markdown = """[<img src="https://raw.githubusercontent.com/axolotl-ai-cloud/axolotl/main/image/axolotl-badge-web.png" alt="Built with Axolotl" width="200" height="32"/>](https://github.com/axolotl-ai-cloud/axolotl)"""
transformers.modelcard.AUTOGENERATED_TRAINER_COMMENT += f"\n{badge_markdown}"
def add_config_to_model_card(cfg: DictDefault):
"""
Add the Axolotl configuration to the model card if available.
Args:
cfg: The configuration dictionary with path to axolotl config file
"""
if getattr(cfg, "axolotl_config_path"):
raw_axolotl_cfg = Path(cfg.axolotl_config_path)
version = get_distribution("axolotl").version
if raw_axolotl_cfg.is_file():
transformers.modelcard.AUTOGENERATED_TRAINER_COMMENT += f"\n<details><summary>See axolotl config</summary>\n\naxolotl version: `{version}`\n```yaml\n{raw_axolotl_cfg.read_text(encoding='utf-8')}\n```\n\n</details><br>\n"
def handle_untrained_tokens_fix(
cfg: DictDefault,
model: PreTrainedModel,
tokenizer: PreTrainedTokenizer,
train_dataset: Any,
safe_serialization: bool,
):
"""
Apply fixes for untrained tokens if configured.
Args:
cfg: The configuration dictionary
model: The model to apply fixes to
tokenizer: The tokenizer for token identification
train_dataset: The training dataset to analyze
safe_serialization: Whether to use safe serialization when saving
"""
if not cfg.fix_untrained_tokens:
return
# check if the `token_ids_to_fix` kwarg exists in the fix_untrained_tokens args
sig = inspect.signature(fix_untrained_tokens)
# if the function has the `token_ids_to_fix` arg, and fix_untrained_tokens is a list
if "token_ids_to_fix" in sig.parameters and isinstance(
cfg.fix_untrained_tokens, list
):
fix_untrained_tokens(
model,
tokenizer,
train_dataset,
token_ids_to_fix=cfg.fix_untrained_tokens,
)
else:
fix_untrained_tokens(model, tokenizer, train_dataset)
if cfg.local_rank == 0:
model.save_pretrained(
str(Path(cfg.output_dir)), safe_serialization=safe_serialization
)
def train(
*, cfg: DictDefault, dataset_meta: TrainDatasetMeta
) -> Tuple[Union[PeftModel, PreTrainedModel], PreTrainedTokenizer]:
"""
Train a model on the given dataset.
Args:
cfg: The configuration dictionary with training parameters
dataset_meta: Metadata about the training dataset
Returns:
Tuple of (model, tokenizer) after training
"""
# Load tokenizer, processor and model
tokenizer, processor, model, peft_config = setup_model_and_tokenizer(cfg)
# Set up reference model for RL if needed
model_ref = setup_reference_model(cfg, tokenizer)
# Determine if we need to resume from a checkpoint
resume_from_checkpoint = determine_resume_checkpoint(cfg)
# Get datasets from metadata
train_dataset = dataset_meta.train_dataset
eval_dataset = dataset_meta.eval_dataset
total_num_steps = dataset_meta.total_num_steps
# Configuration for saving
safe_serialization = cfg.save_safetensors is True
# Set up trainer
trainer = setup_trainer(
cfg,
train_dataset,
eval_dataset,
(model, model_ref, peft_config),
tokenizer,
processor,
total_num_steps,
)
# Handle untrained tokens if configured
handle_untrained_tokens_fix(
cfg, model, tokenizer, train_dataset, safe_serialization
)
# Save initial configs
save_initial_configs(cfg, tokenizer, model, peft_config)
# Set up signal handler for graceful termination
setup_signal_handler(cfg, model, safe_serialization)
# Set up badges and config info for model card
setup_badge_for_model_card()
add_config_to_model_card(cfg)
# Execute the training
execute_training(cfg, trainer, resume_from_checkpoint)
# Save the trained model
save_trained_model(cfg, trainer, model, safe_serialization)
# Create model card
create_model_card(cfg, trainer)
return model, tokenizer
def pretrain_hooks(_cfg, _trainer):
"""
Run hooks right before kicking off the training
:param cfg:
:param trainer:
:return:
"""
def post_train_hooks(_cfg, _trainer):
"""
Run hooks right after training completes
:param cfg:
:param trainer:
:return:
"""