[algo] add ASFT (#10174)

examples/extras/asft/llama2_full_asft.yaml

@@ -0,0 +1,45 @@
+### model
+model_name_or_path: models/Llama-2-7b
+trust_remote_code: true
+
+### method
+stage: sft
+do_train: true
+finetuning_type: full
+deepspeed: examples/deepspeed/ds_z0_config.json
+use_asft_loss: true
+asft_alpha: 0.1
+
+### dataset
+dataset: med
+template: llama2
+cutoff_len: 2048
+max_samples: 10000
+overwrite_cache: true
+preprocessing_num_workers: 16
+dataloader_num_workers: 4
+
+### output
+output_dir: saves/llama2-7b/full/asft2
+logging_steps: 1
+save_steps: 500
+plot_loss: true
+overwrite_output_dir: true
+save_only_model: false
+report_to: none  # choices: [none, wandb, tensorboard, swanlab, mlflow]
+
+### train
+per_device_train_batch_size: 4
+gradient_accumulation_steps: 8
+learning_rate: 2.0e-5
+num_train_epochs: 3.0
+lr_scheduler_type: cosine
+warmup_ratio: 0.1
+bf16: true
+ddp_timeout: 180000000
+
+### eval
+# val_size: 0.1
+# per_device_eval_batch_size: 1
+# eval_strategy: steps
+# eval_steps: 500

examples/extras/asft/qwen2_full_asft.yaml

@@ -0,0 +1,45 @@
+### model
+model_name_or_path: models/Qwen2.5-7B
+trust_remote_code: true
+
+### method
+stage: sft
+do_train: true
+finetuning_type: full
+deepspeed: examples/deepspeed/ds_z0_config.json
+use_asft_loss: true
+asft_alpha: 0.05
+
+### dataset
+dataset: math
+template: qwen
+cutoff_len: 2048
+max_samples: 10000
+overwrite_cache: true
+preprocessing_num_workers: 16
+dataloader_num_workers: 4
+
+### output
+output_dir: saves/qwen2-7b/full/asft
+logging_steps: 10
+save_steps: 500
+plot_loss: true
+overwrite_output_dir: true
+save_only_model: false
+report_to: none  # choices: [none, wandb, tensorboard, swanlab, mlflow]
+
+### train
+per_device_train_batch_size: 4
+gradient_accumulation_steps: 8
+learning_rate: 5.0e-5
+num_train_epochs: 1.0
+lr_scheduler_type: cosine
+warmup_ratio: 0.1
+bf16: true
+ddp_timeout: 180000000
+
+### eval
+# val_size: 0.1
+# per_device_eval_batch_size: 1
+# eval_strategy: steps
+# eval_steps: 500

examples/v1/train_freeze/train_freeze_sft.yaml

@@ -0,0 +1,38 @@
+model: Qwen/Qwen3-4B
+trust_remote_code: true
+model_class: llm
+
+template: qwen3_nothink
+
+# Freeze Configuration
+peft_config:
+  name: freeze
+  freeze_trainable_layers: 2      # Train the last 2 layers
+  freeze_trainable_modules: all       # In these layers, train specific modules
+  freeze_extra_modules: null      # Extra modules to train (e.g. embed_tokens, lm_head)
+
+# Kernel Config
+kernel_config:
+  name: auto
+  include_kernels: auto
+
+# FSDP Config
+dist_config:
+  name: fsdp2
+  dcp_path: null
+
+### data
+train_dataset: data/v1_sft_demo.yaml
+
+### training
+output_dir: ./outputs/test_freeze
+micro_batch_size: 1
+global_batch_size: 4
+cutoff_len: 2048
+learning_rate: 2.0e-5
+bf16: false
+max_steps: 10
+
+### sample
+sample_backend: hf
+max_new_tokens: 128

examples/v1/train_lora/export_lora.yaml

@@ -0,0 +1,7 @@
+model: Qwen/Qwen3-4B
+peft_config:
+  name: lora
+  adapter_name_or_path: ./outputs/test_lora
+  export_dir: ./merge_lora_model
+  export_size: 5
+  infer_dtype: auto

examples/v1/train_lora/train_lora_sft.yaml

@@ -0,0 +1,39 @@
+model: Qwen/Qwen3-4B
+trust_remote_code: true
+model_class: llm
+
+template: qwen3_nothink
+
+# PEFT Configuration
+peft_config:
+  name: lora
+  r: 16
+  lora_alpha: 32
+  lora_dropout: 0.05
+  target_modules: all
+
+# Kernel Config
+kernel_config:
+  name: auto
+  include_kernels: auto
+
+# FSDP Config
+dist_config:
+  name: fsdp2
+  dcp_path: null
+
+### data
+train_dataset: data/v1_sft_demo.yaml
+
+### training
+output_dir: ./outputs/test_lora
+micro_batch_size: 1
+global_batch_size: 4
+cutoff_len: 2048
+learning_rate: 1.0e-4
+bf16: true
+max_steps: 10
+
+### sample
+sample_backend: hf
+max_new_tokens: 128

src/llamafactory/hparams/finetuning_args.py

@@ -490,6 +490,14 @@ class FinetuningArguments(
         default=False,
         metadata={"help": "Whether to use the DFT loss."},
     )
+    use_asft_loss: bool = field(
+        default=False,
+        metadata={"help": "Whether to use the ASFT loss."},
+    )
+    asft_alpha: float = field(
+        default=0.1,
+        metadata={"help": "The alpha parameter for ASFT loss to control the power of adaptive weight."},
+    )
     use_eaft_loss: bool = field(
         default=False,
         metadata={"help": "Whether to use the EAFT loss."},

src/llamafactory/train/sft/trainer.py

@@ -17,6 +17,7 @@
 
 import json
 import os
+from functools import partial
 from types import MethodType
 from typing import TYPE_CHECKING, Any, Optional, Union
 
@@ -52,6 +53,7 @@ class CustomSeq2SeqTrainer(Seq2SeqTrainer):
         processor: Optional["ProcessorMixin"],
         model_args: Optional["ModelArguments"] = None,
         gen_kwargs: Optional[dict[str, Any]] = None,
+        ref_model: Optional["torch.nn.Module"] = None,
         **kwargs,
     ) -> None:
         kwargs["processing_class"] = kwargs.pop("tokenizer")
@@ -82,6 +84,27 @@ class CustomSeq2SeqTrainer(Seq2SeqTrainer):
             self.accelerator.clip_grad_norm_ = MethodType(clip_grad_norm_old_version, self.accelerator)
             self.add_callback(BAdamCallback)
 
+        self.ref_model = ref_model
+
+        if ref_model is not None:
+            from trl.models.utils import prepare_deepspeed, prepare_fsdp
+
+            if getattr(self.accelerator.state, "deepspeed_plugin", None) is not None:
+                if not (
+                    getattr(ref_model, "is_loaded_in_8bit", False) or getattr(ref_model, "is_loaded_in_4bit", False)
+                ):  # quantized models are already set on the correct device
+                    self.ref_model = prepare_deepspeed(self.ref_model, self.accelerator)
+            elif getattr(self.accelerator.state, "fsdp_plugin", None) is not None:
+                if self.accelerator.is_fsdp2:
+                    from accelerate.utils.fsdp_utils import fsdp2_prepare_model
+
+                    self.ref_model = fsdp2_prepare_model(self.accelerator, self.ref_model)
+                else:
+                    self.ref_model = prepare_fsdp(self.ref_model, self.accelerator)
+            else:
+                self.ref_model = self.accelerator.prepare_model(self.ref_model, evaluation_mode=True)
+                self.ref_model.eval()
+
         if finetuning_args.use_dft_loss:
             from ..trainer_utils import dft_loss_func
 
@@ -93,6 +116,13 @@ class CustomSeq2SeqTrainer(Seq2SeqTrainer):
             self.compute_loss_func = lambda outputs, labels, num_items_in_batch=None: eaft_loss_func(
                 outputs, labels, num_items_in_batch, finetuning_args.eaft_alpha
             )
+        elif finetuning_args.use_asft_loss:
+            from ..trainer_utils import asft_loss_func
+
+            self.compute_loss_func = partial(
+                asft_loss_func,
+                asft_alpha=finetuning_args.asft_alpha,
+            )
 
         if training_args.fp8 and hasattr(self, "accelerator"):  # verify FP8 status after trainer initialization
             verify_fp8_status(self.accelerator, training_args)
@@ -119,7 +149,17 @@ class CustomSeq2SeqTrainer(Seq2SeqTrainer):
 
     @override
     def compute_loss(self, model, inputs, *args, **kwargs):
-        return super().compute_loss(model, inputs, *args, **kwargs)
+        if self.finetuning_args.use_asft_loss:
+            with torch.no_grad():
+                ref_outputs = self.ref_model(
+                    input_ids=inputs["input_ids"],
+                    attention_mask=inputs.get("attention_mask", None),
+                )
+                ref_logits = ref_outputs.logits
+            outputs = model(**inputs)
+            return self.compute_loss_func(outputs, inputs["labels"], ref_logits)
+        else:
+            return super().compute_loss(model, inputs, *args, **kwargs)
 
     @override
     def prediction_step(

src/llamafactory/train/sft/workflow.py

@@ -24,7 +24,7 @@ from ...extras.misc import calculate_tps
 from ...extras.packages import is_transformers_version_greater_than
 from ...extras.ploting import plot_loss
 from ...model import load_model, load_tokenizer
-from ..trainer_utils import create_modelcard_and_push
+from ..trainer_utils import create_modelcard_and_push, create_ref_model
 from .metric import ComputeAccuracy, ComputeSimilarity, eval_logit_processor
 from .trainer import CustomSeq2SeqTrainer
 
@@ -52,6 +52,10 @@ def run_sft(
     dataset_module = get_dataset(template, model_args, data_args, training_args, stage="sft", **tokenizer_module)
     model = load_model(tokenizer, model_args, finetuning_args, training_args.do_train)
 
+    ref_model = None
+    if finetuning_args.use_asft_loss:
+        ref_model = create_ref_model(model_args, finetuning_args)
+
     if getattr(model, "is_quantized", False) and not training_args.do_train:
         setattr(model, "_hf_peft_config_loaded", True)  # hack here: make model compatible with prediction
 
@@ -124,6 +128,7 @@ def run_sft(
             data_collator=data_collator,
             callbacks=callbacks,
             gen_kwargs=gen_kwargs,
+            ref_model=ref_model,
             **dataset_module,
             **tokenizer_module,
             **metric_module,

src/llamafactory/train/trainer_utils.py

@@ -23,6 +23,7 @@ from collections.abc import Callable, Mapping
 from typing import TYPE_CHECKING, Any, Optional, Union
 
 import torch
+import torch.nn.functional as F
 from transformers import Trainer
 from transformers.integrations import is_deepspeed_zero3_enabled
 from transformers.modeling_utils import is_fsdp_enabled
@@ -681,6 +682,88 @@ def _dft_cross_entropy(
     return loss
 
 
+def asft_loss_func(
+    outputs,
+    labels: torch.Tensor,
+    ref_logits: torch.Tensor,
+    asft_alpha: float = 0.1,
+    ignore_index: int = -100,
+) -> torch.Tensor:
+    logits = outputs.get("logits")
+    if logits is None:
+        return outputs.get("loss", torch.tensor(0.0))
+
+    logits = logits.float()
+
+    # shift for causal LM
+    shift_logits = logits[..., :-1, :].contiguous()
+    shift_labels = labels[..., 1:].contiguous()
+    shift_ref_logits = ref_logits[..., :-1, :].contiguous()
+
+    vocab_size = shift_logits.size(-1)
+
+    # flatten
+    shift_logits = shift_logits.view(-1, vocab_size)
+    shift_ref_logits = shift_ref_logits.view(-1, vocab_size)
+    shift_labels = shift_labels.view(-1).to(shift_logits.device)
+
+    return _asft_cross_entropy(
+        policy_logits=shift_logits,
+        policy_labels=shift_labels,
+        ref_logits=shift_ref_logits,
+        asft_alpha=asft_alpha,
+        ignore_index=ignore_index,
+    )
+
+
+def _asft_cross_entropy(
+    policy_logits: torch.Tensor,
+    policy_labels: torch.Tensor,
+    ref_logits: torch.Tensor,
+    asft_alpha: float = 0.1,
+    ignore_index: int = -100,
+) -> torch.Tensor:
+    dft_loss = _dft_cross_entropy(
+        policy_logits,
+        policy_labels,
+        ignore_index=ignore_index,
+    )
+
+    kl_loss = _kl_divergence(
+        policy_logits,
+        ref_logits,
+        policy_labels,
+        ignore_index=ignore_index,
+    )
+
+    return dft_loss + asft_alpha * kl_loss
+
+
+def _kl_divergence(
+    policy_logits: torch.Tensor,
+    ref_logits: torch.Tensor,
+    labels: torch.Tensor,
+    ignore_index: int = -100,
+) -> torch.Tensor:
+    # log p(y|x)
+    log_p = F.log_softmax(policy_logits, dim=-1)
+
+    # q(y|x)
+    q = F.softmax(ref_logits, dim=-1)
+
+    # token-wise KL
+    kl = F.kl_div(
+        log_p,
+        q,
+        reduction="none",
+    ).sum(dim=-1)  # [N]
+
+    # mask padding tokens
+    mask = (labels != ignore_index).float()
+
+    return (kl * mask).sum() / mask.sum()
+
+
 def eaft_loss_func(
     outputs: "torch.Tensor",
     labels: "torch.Tensor",

src/llamafactory/v1/core/base_trainer.py

@@ -204,6 +204,16 @@ class BaseTrainer:
     def save_model(self) -> None:
         """Save the model."""
         model_to_save = self.model.module if hasattr(self.model, "module") else self.model
-        model_to_save.save_pretrained(self.args.output_dir)
+        state_dict = None
+        if self.args.dist_config is not None and self.args.dist_config.name == "fsdp2":
+            from torch.distributed.checkpoint.state_dict import StateDictOptions, get_model_state_dict
+
+            options = StateDictOptions(full_state_dict=True, cpu_offload=True)
+            state_dict = get_model_state_dict(self.model, options=options)
+
+        if DistributedInterface().get_rank() != 0:
+            return
+
+        model_to_save.save_pretrained(self.args.output_dir, state_dict=state_dict)
         self.renderer.processor.save_pretrained(self.args.output_dir)
         logger.info_rank0(f"Model saved to {self.args.output_dir}")

src/llamafactory/v1/launcher.py

@@ -125,6 +125,11 @@ def launch():
 
         run_chat()
 
+    elif command == "merge":
+        from llamafactory.v1.plugins.model_plugins.peft import merge_and_export_model
+
+        merge_and_export_model()
+
     elif command == "env":
         raise NotImplementedError("Environment information is not implemented yet.")
 

src/llamafactory/v1/plugins/model_plugins/peft.py

@@ -12,14 +12,22 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Literal, TypedDict
+import re
+from typing import Literal, TypedDict, Union
 
-from peft import LoraConfig, PeftModel, get_peft_model
+import torch
+from peft import LoraConfig, PeftModel, TaskType, get_peft_model
 
+from ...config import InputArgument, get_args
+from ...core.model_engine import ModelEngine
+from ...utils import logging
 from ...utils.plugin import BasePlugin
 from ...utils.types import HFModel
 
 
+logger = logging.get_logger(__name__)
+
+
 class LoraConfigDict(TypedDict, total=False):
     name: Literal["lora"]
     """Plugin name."""
@@ -27,8 +35,28 @@ class LoraConfigDict(TypedDict, total=False):
     """Lora rank."""
     lora_alpha: int
     """Lora alpha."""
-    target_modules: list[str]
+    lora_dropout: float
+    """Lora dropout."""
+    target_modules: Union[list[str], str]
     """Target modules."""
+    use_rslora: bool
+    """Use RS-LoRA."""
+    use_dora: bool
+    """Use DoRA."""
+    modules_to_save: list[str]
+    """Modules to save."""
+    adapter_name_or_path: Union[list[str], str]
+    """Path to the adapter(s)."""
+    export_dir: str
+    """Path to the export directory."""
+    export_size: int
+    """Shard size for the export model."""
+    export_hub_model_id: str
+    """Hub model ID for the export model."""
+    infer_dtype: Literal["auto", "float16", "float32", "bfloat16"]
+    """Inference data type for the export model."""
+    export_legacy_format: bool
+    """Use legacy format for the export model."""
 
 
 class FreezeConfigDict(TypedDict, total=False):
@@ -36,22 +64,280 @@ class FreezeConfigDict(TypedDict, total=False):
     """Plugin name."""
     freeze_trainable_layers: int
     """Freeze trainable layers."""
-    freeze_trainable_modules: list[str] | None
+    freeze_trainable_modules: Union[list[str], str]
     """Freeze trainable modules."""
+    freeze_extra_modules: list[str]
+    """Freeze extra modules."""
+    cast_trainable_params_to_fp32: bool
+    """Cast trainable params to fp32."""
 
 
 class PeftPlugin(BasePlugin):
     def __call__(self, model: HFModel, config: dict, is_train: bool) -> HFModel:
-        return super().__call__(model, config)
+        return super().__call__(model, config, is_train)
+
+
+def _find_all_linear_modules(model: HFModel) -> list[str]:
+    r"""Find all available modules to apply LoRA."""
+    forbidden_modules = {"lm_head", "output_layer", "output"}
+    module_names = set()
+    for name, module in model.named_modules():
+        if any(forbidden_module in name for forbidden_module in forbidden_modules):
+            continue
+
+        if "Linear" in module.__class__.__name__ and "Embedding" not in module.__class__.__name__:
+            module_names.add(name.split(".")[-1])
+
+    return list(module_names)
+
+
+def merge_adapters(model: HFModel, adapter_name_or_path: Union[list[str], str]) -> HFModel:
+    if not isinstance(adapter_name_or_path, list):
+        adapter_name_or_path = [adapter_name_or_path]
+
+    for adapter_path in adapter_name_or_path:
+        model = PeftModel.from_pretrained(model, adapter_path)
+        model = model.merge_and_unload()
+        logger.info_rank0(f"Merged adapter from {adapter_path}")
+
+    return model
+
+
+def load_adapter(model: HFModel, adapter_name_or_path: Union[list[str], str], is_train: bool) -> HFModel:
+    r"""Loads adapter(s) into the model.
+
+    Determine adapter usage based on mode:
+    - Training: Load the single adapter for continued training.
+    - Inference: Merge all adapters to clean up the model.
+    - Unmergeable: Keep the single adapter active without merging.
+    """
+    if not isinstance(adapter_name_or_path, list):
+        adapter_name_or_path = [adapter_name_or_path]
+
+    # TODO
+    # Adapters fix for deepspeed and quant
+    # Adapters fix for vision
+
+    if is_train and len(adapter_name_or_path) > 1:
+        raise ValueError(
+            "When `adapter_name_or_path` is provided for training, only a single LoRA adapter is supported. "
+            "Training will continue on the specified adapter. "
+            "Please merge multiple adapters before starting a new LoRA adapter."
+        )
+
+    if is_train:
+        adapter_to_merge = []
+        adapter_to_resume = adapter_name_or_path[0]
+    else:
+        adapter_to_merge = adapter_name_or_path
+        adapter_to_resume = None
+
+    if adapter_to_merge:
+        model = merge_adapters(model, adapter_to_merge)
+
+    if adapter_to_resume is not None:
+        model = PeftModel.from_pretrained(model, adapter_to_resume, is_trainable=is_train)
+        if is_train:
+            logger.info_rank0(
+                f"Resuming training from existing LoRA adapter at {adapter_to_resume}. "
+                "LoRA hyperparameters will be loaded from the adapter itself; "
+                "the current LoRA configuration will be ignored. "
+                "Merge the adapter into the base model before training if you want to start a new adapter."
+            )
+
+    return model
 
 
 @PeftPlugin("lora").register()
-def get_lora_model(model: HFModel, config: LoraConfigDict, is_train: bool) -> PeftModel:
-    peft_config = LoraConfig(**config)
+def get_lora_model(model: HFModel, config: LoraConfigDict, is_train: bool = False) -> HFModel:
+    adapter_name_or_path = config.get("adapter_name_or_path")
+
+    if adapter_name_or_path:
+        return load_adapter(model, adapter_name_or_path, is_train)
+
+    logger.info_rank0("Fine-tuning method: LoRA")
+
+    target_modules = config.get("target_modules", "all")
+
+    # Handle target modules
+    if target_modules == "all":
+        target_modules = _find_all_linear_modules(model)
+    elif isinstance(target_modules, str):
+        target_modules = [target_modules]
+
+    logger.info_rank0(f"LoRA target modules: {target_modules}")
+
+    peft_config = LoraConfig(
+        task_type=TaskType.CAUSAL_LM,
+        inference_mode=not is_train,
+        r=config.get("r", 8),
+        lora_alpha=config.get("lora_alpha", 16),
+        lora_dropout=config.get("lora_dropout", 0.05),
+        use_rslora=config.get("use_rslora", False),
+        use_dora=config.get("use_dora", False),
+        target_modules=target_modules,
+        modules_to_save=config.get("modules_to_save", None),
+    )
+
     model = get_peft_model(model, peft_config)
+
+    if is_train:
+        model.print_trainable_parameters()
+
     return model
 
 
 @PeftPlugin("freeze").register()
-def get_freeze_model(model: HFModel, config: FreezeConfigDict, is_train: bool) -> HFModel:
-    raise NotImplementedError()
+def get_freeze_model(model: HFModel, config: FreezeConfigDict, is_train: bool = False) -> HFModel:
+    logger.info_rank0("Fine-tuning method: Freeze")
+
+    if not is_train:
+        return model
+
+    freeze_trainable_layers = config.get("freeze_trainable_layers", 2)
+    freeze_trainable_modules = config.get("freeze_trainable_modules", ["all"])
+    freeze_extra_modules = config.get("freeze_extra_modules", [])
+    cast_trainable_params_to_fp32 = config.get("cast_trainable_params_to_fp32", True)
+
+    if isinstance(freeze_trainable_modules, str):
+        freeze_trainable_modules = [module.strip() for module in freeze_trainable_modules.split(",")]
+
+    if isinstance(freeze_extra_modules, str):
+        freeze_extra_modules = [module.strip() for module in freeze_extra_modules.split(",")]
+
+    # Get number of layers
+    num_layers = (
+        getattr(model.config, "num_hidden_layers", None)
+        or getattr(model.config, "num_layers", None)
+        or getattr(model.config, "n_layer", None)
+    )
+
+    if not num_layers:
+        raise ValueError("Current model does not support freeze tuning.")
+
+    if freeze_trainable_layers > 0:
+        # last n layers
+        trainable_layer_ids = range(max(0, num_layers - freeze_trainable_layers), num_layers)
+    else:
+        # first n layers
+        trainable_layer_ids = range(min(-freeze_trainable_layers, num_layers))
+
+    # Identify hidden and non-hidden modules
+    hidden_modules = set()
+    non_hidden_modules = set()
+    for name, _ in model.named_parameters():
+        if ".0." in name:
+            hidden_modules.add(name.split(".0.")[-1].split(".")[0])
+        elif ".1." in name:
+            hidden_modules.add(name.split(".1.")[-1].split(".")[0])
+
+        if re.search(r"\.\d+\.", name) is None:
+            non_hidden_modules.add(name.split(".")[-2])
+
+    # Build list of trainable layer patterns
+    trainable_layers = []
+    for module_name in freeze_trainable_modules:
+        if module_name == "all":
+            for idx in trainable_layer_ids:
+                trainable_layers.append(f".{idx:d}.")
+        elif module_name in hidden_modules:
+            for idx in trainable_layer_ids:
+                trainable_layers.append(f".{idx:d}.{module_name}")
+        else:
+            raise ValueError(f"Module {module_name} not found in hidden modules: {hidden_modules}")
+
+    # Add extra modules
+    if freeze_extra_modules:
+        for module_name in freeze_extra_modules:
+            if module_name in non_hidden_modules:
+                trainable_layers.append(module_name)
+            else:
+                raise ValueError(f"Module {module_name} not found in non-hidden modules: {non_hidden_modules}")
+
+    # TODO
+    # Multi-modal special handling
+
+    # Set requires_grad
+    forbidden_modules = {"quant_state", "quantization_weight", "qweight", "qzeros", "scales"}
+    for name, param in model.named_parameters():
+        if any(trainable_layer in name for trainable_layer in trainable_layers) and not any(
+            forbidden_module in name for forbidden_module in forbidden_modules
+        ):
+            param.requires_grad_(True)
+            if cast_trainable_params_to_fp32:
+                param.data = param.data.to(torch.float32)  # Cast to fp32 for stability
+        else:
+            param.requires_grad_(False)
+
+    logger.info_rank0(f"Set trainable layers: {trainable_layers}")
+
+    # Count trainable params for verification
+    trainable_params = sum(p.numel() for p in model.parameters() if p.requires_grad)
+    all_params = sum(p.numel() for p in model.parameters())
+    logger.info_rank0(
+        f"trainable params: {trainable_params} || all params: {all_params} || trainable%: {100 * trainable_params / all_params:.4f}"
+    )
+
+    return model
+
+
+def merge_and_export_model(args: InputArgument = None):
+    model_args, _, _, _ = get_args(args)
+
+    export_config = model_args.peft_config
+    if export_config is None:
+        raise ValueError("Please specify peft_config to merge and export model.")
+
+    export_dir = export_config.get("export_dir")
+    if export_dir is None:
+        raise ValueError("Please specify export_dir.")
+
+    export_size = export_config.get("export_size", 5)
+    export_hub_model_id = export_config.get("export_hub_model_id")
+    infer_dtype = export_config.get("infer_dtype", "auto")
+    export_legacy_format = export_config.get("export_legacy_format", False)
+
+    adapters = None
+    if export_config.get("name") == "lora":
+        adapters = export_config.get("adapter_name_or_path")
+    else:
+        raise ValueError("Currently merge and export model function is only supported for lora.")
+
+    if adapters is None:
+        raise ValueError("Please set adapter_name_or_path to merge adapters into base model.")
+
+    logger.info_rank0("Loading model for export...")
+    model_engine = ModelEngine(model_args, is_train=False)
+    model = model_engine.model
+    tokenizer = model_engine.processor
+
+    if infer_dtype == "auto":
+        if model.config.torch_dtype == torch.float32 and torch.cuda.is_bf16_supported():
+            model = model.to(torch.bfloat16)
+            logger.info_rank0("Converted model to bfloat16.")
+    else:
+        target_dtype = getattr(torch, infer_dtype)
+        model = model.to(target_dtype)
+        logger.info_rank0(f"Converted model to {infer_dtype}.")
+
+    logger.info_rank0(f"Exporting model to {export_dir}...")
+    model.save_pretrained(
+        export_dir,
+        max_shard_size=f"{export_size}GB",
+        safe_serialization=not export_legacy_format,
+    )
+    if tokenizer is not None:
+        try:
+            if hasattr(tokenizer, "padding_side"):
+                tokenizer.padding_side = "left"
+            tokenizer.save_pretrained(export_dir)
+        except Exception as e:
+            logger.warning(f"Failed to save tokenizer: {e}")
+
+    if export_hub_model_id:
+        logger.info_rank0(f"Pushing to hub: {export_hub_model_id}...")
+        model.push_to_hub(export_hub_model_id)
+        if tokenizer is not None:
+            tokenizer.push_to_hub(export_hub_model_id)
+
+    logger.info_rank0("Model exported successfully.")

src/llamafactory/v1/plugins/trainer_plugins/distributed/fsdp2.py

@@ -24,6 +24,7 @@ from torch.distributed.fsdp import (
     fully_shard,
 )
 from transformers import PreTrainedModel
+from peft.tuners.lora import LoraLayer
 
 from ....accelerator.helper import get_current_accelerator
 from ....accelerator.interface import DistributedInterface
@@ -93,6 +94,10 @@ class FSDP2Engine:
             reduce_dtype=reduce_dtype,
             cast_forward_inputs=True,
         )
+    
+
+    def is_lora_module_wrap(self, model) -> bool:
+        return any(isinstance(module, LoraLayer) for module in model.modules())
 
     def prepare_model(self, model: PreTrainedModel) -> PreTrainedModel:
         if self.fsdp_mesh is None:
@@ -110,6 +115,26 @@ class FSDP2Engine:
         else:
             logger.info(f"Applying per-layer FSDP to {layer_cls.__name__}")
             transformer_layer_cls_to_wrap = {layer_cls}
+        
+        if self.is_lora_module_wrap(model):
+            lora_modules = []
+            for module in model.modules():
+
+                if len(list(module.children())) != 0:
+                    continue
+                if any(param.requires_grad for param in module.parameters(recurse=False)):
+                    lora_modules.append(module)
+
+            for module in lora_modules:
+                fully_shard(
+                    module,
+                    mesh=self.fsdp_mesh,
+                    reshard_after_forward=self.reshard_after_forward,
+                    mp_policy=mp_policy,
+                    offload_policy=CPUOffloadPolicy(pin_memory=self.pin_memory) if self.offload_params else None,
+                )
+
+            logger.info(f"Applying FSDP wrap for LoRA layer separately.")
 
         for name, module in model.named_modules():
             should_wrap = False
@@ -154,7 +179,6 @@ class FSDP2Engine:
         )
 
         return model
-
     @torch.no_grad()
     def materialize_and_load(self, model: PreTrainedModel, hf_model_path: str, dcp_path: str = None):
         if self.rank == 0:

src/llamafactory/v1/trainers/sft_trainer.py

@@ -33,7 +33,7 @@ def run_sft(args: InputArgument = None):
     model_args, data_args, training_args, _ = get_args(args)
     DistributedInterface(training_args.dist_config)
     train_dataset = DataEngine(data_args.train_dataset)
-    model_engine = ModelEngine(model_args)
+    model_engine = ModelEngine(model_args, is_train=True)
     trainer = SFTTrainer(
         args=training_args,
         model=model_engine.model,

tests_v1/plugins/model_plugins/test_peft.py

@@ -0,0 +1,156 @@
+# Copyright 2025 the LlamaFactory team.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import pytest
+from peft import LoraConfig, PeftModel, get_peft_model
+from transformers import AutoModelForCausalLM, AutoTokenizer
+
+from llamafactory.v1.plugins.model_plugins import peft as peft_module
+from llamafactory.v1.plugins.model_plugins.peft import merge_and_export_model
+
+
+TINY_MODEL = "llamafactory/tiny-random-qwen3"
+
+
+@pytest.fixture(scope="module")
+def model_path():
+    return TINY_MODEL
+
+
+@pytest.fixture(scope="function")
+def model(model_path):
+    return AutoModelForCausalLM.from_pretrained(model_path)
+
+
+@pytest.fixture(scope="function")
+def tokenizer(model_path):
+    return AutoTokenizer.from_pretrained(model_path)
+
+
+@pytest.fixture(scope="function")
+def adapter_path(tmp_path):
+    # Create a dummy adapter
+    lora_config = LoraConfig(
+        r=8,
+        lora_alpha=16,
+        target_modules=["q_proj", "v_proj"],
+        lora_dropout=0.05,
+        bias="none",
+        task_type="CAUSAL_LM",
+    )
+
+    base_model = AutoModelForCausalLM.from_pretrained(TINY_MODEL)
+    peft_model = get_peft_model(base_model, lora_config)
+    save_path = tmp_path / "test_adapter"
+    peft_model.save_pretrained(save_path)
+    return str(save_path)
+
+
+def test_find_all_linear_modules(model):
+    """Verify linear modules are discoverable and include q_proj / v_proj for tiny-random-qwen3."""
+    modules = peft_module._find_all_linear_modules(model)
+    expected_subset = {"q_proj", "v_proj"}
+    assert expected_subset.issubset(set(modules))
+
+
+def test_get_lora_model(model):
+    """Verify a PeftModel is returned and LoRA config takes effect."""
+    config = {"name": "lora", "r": 8, "target_modules": "all", "lora_alpha": 16}
+    model = peft_module.get_lora_model(model, config, is_train=True)
+    assert isinstance(model, PeftModel)
+    assert model.peft_config["default"].r == 8
+    assert "q_proj" in model.peft_config["default"].target_modules
+
+
+def test_get_freeze_model_layers(model):
+    """Verify layer-wise freezing: only the last layer stays trainable."""
+    # Freeze all but last layer
+    config = {"name": "freeze", "freeze_trainable_layers": 1, "freeze_trainable_modules": "all"}
+
+    # Ensure we start with something known
+    model = peft_module.get_freeze_model(model, config, is_train=True)
+
+    num_layers = model.config.num_hidden_layers
+    assert num_layers > 0
+
+    for name, param in model.named_parameters():
+        if f"layers.{num_layers - 1}" in name:
+            assert param.requires_grad, f"{name} should be trainable"
+        elif "layers.0" in name and num_layers > 1:
+            assert not param.requires_grad, f"{name} should be frozen"
+
+
+def test_get_freeze_model_modules(model):
+    """Verify module-wise freezing: only last-layer self_attn is trainable."""
+    # Freeze specific modules (e.g. only self_attn)
+    config = {"name": "freeze", "freeze_trainable_layers": 1, "freeze_trainable_modules": "self_attn"}
+    model = peft_module.get_freeze_model(model, config, is_train=True)
+
+    num_layers = model.config.num_hidden_layers
+
+    for name, param in model.named_parameters():
+        if f"layers.{num_layers - 1}" in name and "self_attn" in name:
+            assert param.requires_grad, f"{name} should be trainable"
+        else:
+            assert not param.requires_grad, f"{name} should be frozen"
+
+
+def test_load_adapter_single_for_inference(model, adapter_path):
+    """Verify single adapter is merged+unloaded in inference mode."""
+    # Test loading single adapter for inference (merge and unload)
+    model_result = peft_module.load_adapter(model, adapter_path, is_train=False)
+    assert not isinstance(model_result, PeftModel)
+
+
+def test_load_adapter_resume_train(model, adapter_path):
+    """Verify training mode returns a trainable PeftModel."""
+    # Test loading for training
+    model_result = peft_module.load_adapter(model, adapter_path, is_train=True)
+    assert isinstance(model_result, PeftModel)
+
+
+def test_load_adapter_train_multiple_disallowed(model, adapter_path):
+    """Verify multiple adapters are rejected in training mode."""
+    with pytest.raises(ValueError, match="only a single LoRA adapter"):
+        peft_module.load_adapter(model, [adapter_path, adapter_path], is_train=True)
+
+
+def test_load_adapter_infer_multiple_merges(model, adapter_path):
+    """Verify multiple adapters are merged in inference mode."""
+    # Test merging multiple adapters
+    model_result = peft_module.load_adapter(model, [adapter_path, adapter_path], is_train=False)
+    assert not isinstance(model_result, PeftModel)
+
+
+def test_merge_and_export_model(tmp_path, adapter_path):
+    """Verify merge_and_export_model produces export artifacts."""
+    export_dir = tmp_path / "export"
+
+    args_dict = {
+        "model": TINY_MODEL,
+        "peft_config": {
+            "name": "lora",
+            "adapter_name_or_path": adapter_path,
+            "export_dir": str(export_dir),
+            "export_size": 1,
+            "infer_dtype": "float16",
+        },
+    }
+
+    merge_and_export_model(args_dict)
+
+    assert export_dir.exists()
+    assert (export_dir / "config.json").exists()
+    assert (export_dir / "model.safetensors").exists()
+    assert (export_dir / "tokenizer_config.json").exists()