disentangle model from tuner and rename modules

src/llmtuner/train/ppo/workflow.py

@@ -0,0 +1,92 @@
+# Inspired by: https://github.com/lvwerra/trl/blob/main/examples/research_projects/stack_llama/scripts/rl_training.py
+
+import math
+from trl import PPOConfig
+from torch.optim import AdamW
+from typing import TYPE_CHECKING, Optional, List
+from transformers import DataCollatorWithPadding
+from transformers.optimization import get_scheduler
+
+from llmtuner.data import get_dataset, preprocess_dataset
+from llmtuner.extras.callbacks import SavePeftModelCallback
+from llmtuner.extras.ploting import plot_loss
+from llmtuner.model import load_model_and_tokenizer
+from llmtuner.train.ppo.trainer import CustomPPOTrainer
+
+if TYPE_CHECKING:
+    from transformers import Seq2SeqTrainingArguments, TrainerCallback
+    from llmtuner.hparams import ModelArguments, DataArguments, FinetuningArguments, GeneratingArguments
+
+
+def run_ppo(
+    model_args: "ModelArguments",
+    data_args: "DataArguments",
+    training_args: "Seq2SeqTrainingArguments",
+    finetuning_args: "FinetuningArguments",
+    generating_args: "GeneratingArguments",
+    callbacks: Optional[List["TrainerCallback"]] = None
+):
+    dataset = get_dataset(model_args, data_args)
+    model, tokenizer = load_model_and_tokenizer(model_args, finetuning_args, training_args.do_train, stage="ppo")
+    dataset = preprocess_dataset(dataset, tokenizer, data_args, training_args, stage="ppo")
+
+    tokenizer.padding_side = "left" # use left-padding in generation while using right-padding in training
+    data_collator = DataCollatorWithPadding(tokenizer=tokenizer)
+
+    ppo_config = PPOConfig(
+        model_name=model_args.model_name_or_path,
+        learning_rate=training_args.learning_rate,
+        mini_batch_size=training_args.per_device_train_batch_size,
+        batch_size=training_args.per_device_train_batch_size * training_args.gradient_accumulation_steps,
+        gradient_accumulation_steps=training_args.gradient_accumulation_steps,
+        ppo_epochs=1,
+        max_grad_norm=training_args.max_grad_norm,
+        seed=training_args.seed,
+        optimize_device_cache=True,
+        target=finetuning_args.ppo_target,
+        log_with=finetuning_args.ppo_logger,
+        use_score_scaling=finetuning_args.ppo_score_norm,
+        use_score_norm=finetuning_args.ppo_score_norm,
+        accelerator_kwargs={"step_scheduler_with_optimizer": False}
+    )
+
+    optimizer = AdamW(filter(lambda p: p.requires_grad, model.parameters()), lr=training_args.learning_rate)
+    if training_args.max_steps > 0:
+        num_training_steps = training_args.max_steps
+    else:
+        total_train_batch_size = (
+            training_args.per_device_train_batch_size * training_args.gradient_accumulation_steps * training_args.world_size
+        )
+        num_training_steps = training_args.num_train_epochs * math.ceil(len(dataset) / total_train_batch_size)
+
+    lr_scheduler = get_scheduler(
+        training_args.lr_scheduler_type,
+        optimizer=optimizer,
+        num_warmup_steps=training_args.get_warmup_steps(num_training_steps),
+        num_training_steps=num_training_steps
+    )
+
+    # Initialize our Trainer
+    ppo_trainer = CustomPPOTrainer(
+        model_args=model_args,
+        training_args=training_args,
+        finetuning_args=finetuning_args,
+        generating_args=generating_args,
+        callbacks=callbacks + [SavePeftModelCallback()],
+        config=ppo_config,
+        model=model,
+        ref_model=None,
+        tokenizer=tokenizer,
+        dataset=dataset,
+        data_collator=data_collator,
+        optimizer=optimizer,
+        lr_scheduler=lr_scheduler
+    )
+
+    # Training
+    if training_args.do_train:
+        ppo_trainer.ppo_train()
+        ppo_trainer.save_model()
+        ppo_trainer.save_state() # must be called after save_model to have a folder
+        if ppo_trainer.is_world_process_zero() and model_args.plot_loss:
+            plot_loss(training_args.output_dir, keys=["loss", "reward"])