refactor pissa, improve llamaboard

Former-commit-id: 619556e46c19718f702c97df5d570a2a4c5fb13a

src/llamafactory/train/ppo/workflow.py

@@ -20,10 +20,9 @@ from typing import TYPE_CHECKING, List, Optional
 from transformers import DataCollatorWithPadding
 
 from ...data import get_dataset
-from ...extras.callbacks import FixValueHeadModelCallback
-from ...extras.misc import fix_valuehead_checkpoint
 from ...extras.ploting import plot_loss
 from ...model import load_model, load_tokenizer
+from ..callbacks import FixValueHeadModelCallback, fix_valuehead_checkpoint
 from ..trainer_utils import create_ref_model, create_reward_model
 from .trainer import CustomPPOTrainer
 
@@ -75,6 +74,7 @@ def run_ppo(
         ppo_trainer.save_model()
         if training_args.should_save:
             fix_valuehead_checkpoint(model, training_args.output_dir, training_args.save_safetensors)
+
         ppo_trainer.save_state()  # must be called after save_model to have a folder
         if ppo_trainer.is_world_process_zero() and finetuning_args.plot_loss:
             plot_loss(training_args.output_dir, keys=["loss", "reward"])