diff --git a/src/llmtuner/dsets/preprocess.py b/src/llmtuner/dsets/preprocess.py
index c42b2047..320a54ef 100644
--- a/src/llmtuner/dsets/preprocess.py
+++ b/src/llmtuner/dsets/preprocess.py
@@ -44,10 +44,10 @@ def preprocess_dataset(
         tokenized_examples = tokenizer(examples["prompt"], **kwargs)
         concatenated_examples = {k: list(chain(*tokenized_examples[k])) for k in tokenized_examples.keys()}
         total_length = len(concatenated_examples[list(concatenated_examples.keys())[0]])
-        block_size = data_args.max_source_length
+        block_size = data_args.cutoff_len
         # we drop the small remainder, and if the total_length < block_size, we exclude this batch
         total_length = (total_length // block_size) * block_size
-        # split by chunks of max_source_length
+        # split by chunks of cutoff_len
         result = {
             k: [t[i: i + block_size] for i in range(0, total_length, block_size)]
             for k, t in concatenated_examples.items()
@@ -58,7 +58,6 @@ def preprocess_dataset(
         # build inputs with format `<bos> X Y <eos>` and labels with format `<ignore> ... <ignore> Y <eos>`
         # for multiturn examples, we only mask the prompt part in each prompt-response pair.
         model_inputs = {"input_ids": [], "attention_mask": [], "labels": []}
-        max_length = data_args.max_source_length + data_args.max_target_length
 
         for query, response, history, system in construct_example(examples):
             input_ids, labels = [], []
@@ -66,13 +65,14 @@ def preprocess_dataset(
             for turn_idx, (source_ids, target_ids) in enumerate(template.encode_multiturn(
                 tokenizer, query, response, history, system
             )):
-                if len(source_ids) > data_args.max_source_length:
-                    source_ids = source_ids[:data_args.max_source_length]
-                if len(target_ids) > data_args.max_target_length:
-                    target_ids = target_ids[:data_args.max_target_length]
+                total_len = len(source_ids) + len(target_ids)
+                max_source_len = int(data_args.cutoff_len * (len(source_ids) / total_len))
+                max_target_len = int(data_args.cutoff_len * (len(target_ids) / total_len))
 
-                if len(input_ids) + len(source_ids) + len(target_ids) > max_length:
-                    break
+                if len(source_ids) > max_source_len:
+                    source_ids = source_ids[:max_source_len]
+                if len(target_ids) > max_target_len:
+                    target_ids = target_ids[:max_target_len]
 
                 if turn_idx != 0 and template.efficient_eos:
                     source_mask = [tokenizer.eos_token_id] + [IGNORE_INDEX] * (len(source_ids) - 1)
@@ -86,6 +86,10 @@ def preprocess_dataset(
                 input_ids += [tokenizer.eos_token_id]
                 labels += [tokenizer.eos_token_id]
 
+            if len(input_ids) > data_args.cutoff_len:
+                input_ids = input_ids[:data_args.cutoff_len]
+                labels = labels[:data_args.cutoff_len]
+
             model_inputs["input_ids"].append(input_ids)
             model_inputs["attention_mask"].append([1] * len(input_ids))
             model_inputs["labels"].append(labels)
@@ -97,19 +101,19 @@ def preprocess_dataset(
         model_inputs = {"input_ids": [], "attention_mask": [], "labels": []}
 
         for query, response, history, system in construct_example(examples):
-            source_ids, target_ids = template.encode_oneturn(tokenizer, query, response, history, system)
-
-            if len(source_ids) > data_args.max_source_length:
-                source_ids = source_ids[:data_args.max_source_length]
-            if len(target_ids) > data_args.max_target_length:
-                target_ids = target_ids[:data_args.max_target_length]
+            input_ids, labels = template.encode_oneturn(tokenizer, query, response, history, system)
 
             if template.efficient_eos:
-                target_ids += [tokenizer.eos_token_id]
+                labels += [tokenizer.eos_token_id]
 
-            model_inputs["input_ids"].append(source_ids)
-            model_inputs["attention_mask"].append([1] * len(source_ids))
-            model_inputs["labels"].append(target_ids)
+            if len(input_ids) > data_args.cutoff_len:
+                input_ids = input_ids[:data_args.cutoff_len]
+            if len(labels) > data_args.cutoff_len:
+                labels = labels[:data_args.cutoff_len]
+
+            model_inputs["input_ids"].append(input_ids)
+            model_inputs["attention_mask"].append([1] * len(input_ids))
+            model_inputs["labels"].append(labels)
 
         return model_inputs
 
@@ -120,17 +124,21 @@ def preprocess_dataset(
             prompt_ids, chosen_ids = template.encode_oneturn(tokenizer, query, response[0], history, system)
             _, rejected_ids = template.encode_oneturn(tokenizer, query, response[1], history, system)
 
-            if len(prompt_ids) > data_args.max_source_length:
-                prompt_ids = prompt_ids[:data_args.max_source_length]
-            if len(chosen_ids) > data_args.max_target_length:
-                chosen_ids = chosen_ids[:data_args.max_target_length]
-            if len(rejected_ids) > data_args.max_target_length:
-                rejected_ids = rejected_ids[:data_args.max_target_length]
-
             if template.efficient_eos:
                 chosen_ids += [tokenizer.eos_token_id]
                 rejected_ids += [tokenizer.eos_token_id]
 
+            total_len = len(prompt_ids) + max(len(chosen_ids), len(rejected_ids))
+            max_source_len = int(data_args.cutoff_len * (len(prompt_ids) / total_len))
+            max_target_len = int(data_args.cutoff_len * (max(len(chosen_ids), len(rejected_ids)) / total_len))
+
+            if len(prompt_ids) > max_source_len:
+                prompt_ids = prompt_ids[:max_source_len]
+            if len(chosen_ids) > max_target_len:
+                chosen_ids = chosen_ids[:max_target_len]
+            if len(rejected_ids) > max_target_len:
+                rejected_ids = rejected_ids[:max_target_len]
+
             model_inputs["prompt_ids"].append(prompt_ids)
             model_inputs["chosen_ids"].append(chosen_ids)
             model_inputs["rejected_ids"].append(rejected_ids)
diff --git a/src/llmtuner/hparams/data_args.py b/src/llmtuner/hparams/data_args.py
index 2a044076..02a603f0 100644
--- a/src/llmtuner/hparams/data_args.py
+++ b/src/llmtuner/hparams/data_args.py
@@ -42,12 +42,16 @@ class DataArguments:
         default="train",
         metadata={"help": "Which dataset split to use for training and evaluation."}
     )
+    cutoff_len: Optional[int] = field(
+        default=1024,
+        metadata={"help": "The maximum length of the model inputs after tokenization."}
+    )
     streaming: Optional[bool] = field(
         default=False,
         metadata={"help": "Enable streaming mode."}
     )
     buffer_size: Optional[int] = field(
-        default=1024,
+        default=16384,
         metadata={"help": "Size of the buffer to randomly sample examples from in streaming mode."}
     )
     mix_strategy: Optional[Literal["concat", "interleave_under", "interleave_over"]] = field(
@@ -66,14 +70,6 @@ class DataArguments:
         default=None,
         metadata={"help": "The number of processes to use for the preprocessing."}
     )
-    max_source_length: Optional[int] = field(
-        default=512,
-        metadata={"help": "The maximum total input sequence length after tokenization."}
-    )
-    max_target_length: Optional[int] = field(
-        default=512,
-        metadata={"help": "The maximum total output sequence length after tokenization."}
-    )
     max_samples: Optional[int] = field(
         default=None,
         metadata={"help": "For debugging purposes, truncate the number of examples for each dataset."}
diff --git a/src/llmtuner/hparams/model_args.py b/src/llmtuner/hparams/model_args.py
index f8dc207d..0d7a3d52 100644
--- a/src/llmtuner/hparams/model_args.py
+++ b/src/llmtuner/hparams/model_args.py
@@ -63,18 +63,10 @@ class ModelArguments:
         default=None,
         metadata={"help": "Auth token to log in with Hugging Face Hub."}
     )
-    compute_dtype: Optional[torch.dtype] = field(
-        default=None,
-        metadata={"help": "Used in quantization configs. Do not specify this argument manually."}
-    )
-    model_max_length: Optional[int] = field(
-        default=None,
-        metadata={"help": "Used in rope scaling. Do not specify this argument manually."}
-    )
 
     def __post_init__(self):
-        if self.compute_dtype is not None or self.model_max_length is not None:
-            raise ValueError("These arguments cannot be specified.")
+        self.compute_dtype = None
+        self.model_max_length = None
 
         if self.checkpoint_dir is not None: # support merging multiple lora weights
             self.checkpoint_dir = [cd.strip() for cd in self.checkpoint_dir.split(",")]
diff --git a/src/llmtuner/tuner/core/loader.py b/src/llmtuner/tuner/core/loader.py
index a14e02a7..911b0c5d 100644
--- a/src/llmtuner/tuner/core/loader.py
+++ b/src/llmtuner/tuner/core/loader.py
@@ -173,7 +173,7 @@ def load_model_and_tokenizer(
     )
 
     # Disable custom generate method (for Qwen)
-    if "GenerationMixin" not in str(model.generate.__func__):
+    if isinstance(model, PreTrainedModel) and "GenerationMixin" not in str(model.generate.__func__):
         model.generate = MethodType(PreTrainedModel.generate, model)
 
     # Fix LM head (for ChatGLM2)
diff --git a/src/llmtuner/tuner/core/parser.py b/src/llmtuner/tuner/core/parser.py
index 47fb8b2d..e5ebcb78 100644
--- a/src/llmtuner/tuner/core/parser.py
+++ b/src/llmtuner/tuner/core/parser.py
@@ -213,7 +213,7 @@ def get_train_args(
     else:
         model_args.compute_dtype = torch.float32
 
-    model_args.model_max_length = data_args.max_source_length + data_args.max_target_length
+    model_args.model_max_length = data_args.cutoff_len
 
     # Log on each process the small summary:
     logger.info("Process rank: {}, device: {}, n_gpu: {}\n  distributed training: {}, compute dtype: {}".format(
diff --git a/src/llmtuner/tuner/ppo/trainer.py b/src/llmtuner/tuner/ppo/trainer.py
index 767e85ce..ce5ecb98 100644
--- a/src/llmtuner/tuner/ppo/trainer.py
+++ b/src/llmtuner/tuner/ppo/trainer.py
@@ -2,13 +2,13 @@ import os
 import math
 import torch
 from tqdm import tqdm
-from typing import TYPE_CHECKING, Any, Callable, Dict, List, Optional, Tuple
+from typing import TYPE_CHECKING, Any, Dict, List, Optional, Tuple
 
 from transformers import GenerationConfig, Trainer, TrainerState, TrainerControl
 from transformers.trainer_utils import PREFIX_CHECKPOINT_DIR
 
 from trl import PPOTrainer
-from trl.core import LengthSampler, PPODecorators, logprobs_from_logits
+from trl.core import PPODecorators, logprobs_from_logits
 
 from llmtuner.extras.logging import get_logger
 from llmtuner.extras.misc import AverageMeter, count_parameters, get_logits_processor
@@ -47,7 +47,7 @@ class CustomPPOTrainer(PPOTrainer, Trainer):
         self.state = TrainerState()
         self.control = TrainerControl()
 
-    def ppo_train(self, max_target_length: int) -> None:
+    def ppo_train(self) -> None:
         r"""
         Implements training loop for the PPO stage, like _inner_training_loop() in Huggingface's Trainer.
         """
@@ -81,9 +81,7 @@ class CustomPPOTrainer(PPOTrainer, Trainer):
             pad_token_id=self.tokenizer.pad_token_id
         ))
 
-        length_sampler = LengthSampler(max_target_length // 2, max_target_length)
         unwrapped_model: "AutoModelForCausalLMWithValueHead" = self.accelerator.unwrap_model(self.model)
-
         dataiter = iter(self.dataloader)
         steps_trained = 0
         loss_meter = AverageMeter()
@@ -100,7 +98,7 @@ class CustomPPOTrainer(PPOTrainer, Trainer):
             self.model.eval()
 
             # Get inputs
-            queries, responses = self.get_inputs(batch, length_sampler, generating_args)
+            queries, responses = self.get_inputs(batch, generating_args)
             self.tokenizer.padding_side = "right" # change padding side
             rewards = self.get_rewards(queries, responses, unwrapped_model)
 
@@ -156,13 +154,11 @@ class CustomPPOTrainer(PPOTrainer, Trainer):
     def get_inputs(
         self,
         batch: Dict[str, torch.Tensor],
-        length_sampler: Callable,
         generating_args: Dict[str, Any]
     ) -> Tuple[List[torch.Tensor], List[torch.Tensor]]:
         r"""
         Generates model's responses given queries.
         """
-        generating_args["max_new_tokens"] = length_sampler()
         gen_kwargs = dict(
             generation_config=GenerationConfig(**generating_args),
             logits_processor=get_logits_processor(),
diff --git a/src/llmtuner/tuner/ppo/workflow.py b/src/llmtuner/tuner/ppo/workflow.py
index 4cfec75b..be8fca5d 100644
--- a/src/llmtuner/tuner/ppo/workflow.py
+++ b/src/llmtuner/tuner/ppo/workflow.py
@@ -79,7 +79,7 @@ def run_ppo(
 
     # Training
     if training_args.do_train:
-        ppo_trainer.ppo_train(max_target_length=data_args.max_target_length)
+        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:
diff --git a/src/llmtuner/webui/components/eval.py b/src/llmtuner/webui/components/eval.py
index cbc71daf..d37fe746 100644
--- a/src/llmtuner/webui/components/eval.py
+++ b/src/llmtuner/webui/components/eval.py
@@ -28,12 +28,16 @@ def create_eval_tab(top_elems: Dict[str, "Component"], runner: "Runner") -> Dict
     )
 
     with gr.Row():
-        max_source_length = gr.Slider(value=512, minimum=4, maximum=4096, step=1)
-        max_target_length = gr.Slider(value=512, minimum=4, maximum=4096, step=1)
+        cutoff_len = gr.Slider(value=1024, minimum=4, maximum=8192, step=1)
         max_samples = gr.Textbox(value="100000")
         batch_size = gr.Slider(value=8, minimum=1, maximum=512, step=1)
         predict = gr.Checkbox(value=True)
 
+    with gr.Row():
+        max_new_tokens = gr.Slider(10, 2048, value=128, step=1)
+        top_p = gr.Slider(0.01, 1, value=0.7, step=0.01)
+        temperature = gr.Slider(0.01, 1.5, value=0.95, step=0.01)
+
     with gr.Row():
         cmd_preview_btn = gr.Button()
         start_btn = gr.Button()
@@ -55,11 +59,13 @@ def create_eval_tab(top_elems: Dict[str, "Component"], runner: "Runner") -> Dict
         top_elems["system_prompt"],
         dataset_dir,
         dataset,
-        max_source_length,
-        max_target_length,
+        cutoff_len,
         max_samples,
         batch_size,
-        predict
+        predict,
+        max_new_tokens,
+        top_p,
+        temperature
     ]
 
     output_components = [
@@ -78,11 +84,13 @@ def create_eval_tab(top_elems: Dict[str, "Component"], runner: "Runner") -> Dict
         preview_count=preview_count,
         preview_samples=preview_samples,
         close_btn=close_btn,
-        max_source_length=max_source_length,
-        max_target_length=max_target_length,
+        cutoff_len=cutoff_len,
         max_samples=max_samples,
         batch_size=batch_size,
         predict=predict,
+        max_new_tokens=max_new_tokens,
+        top_p=top_p,
+        temperature=temperature,
         cmd_preview_btn=cmd_preview_btn,
         start_btn=start_btn,
         stop_btn=stop_btn,
diff --git a/src/llmtuner/webui/components/train.py b/src/llmtuner/webui/components/train.py
index 5d054d64..cc58def9 100644
--- a/src/llmtuner/webui/components/train.py
+++ b/src/llmtuner/webui/components/train.py
@@ -35,11 +35,11 @@ def create_train_tab(top_elems: Dict[str, "Component"], runner: "Runner") -> Dic
     )
 
     with gr.Row():
-        max_source_length = gr.Slider(value=512, minimum=4, maximum=4096, step=1)
-        max_target_length = gr.Slider(value=512, minimum=4, maximum=4096, step=1)
+        cutoff_len = gr.Slider(value=1024, minimum=4, maximum=8192, step=1)
         learning_rate = gr.Textbox(value="5e-5")
         num_train_epochs = gr.Textbox(value="3.0")
         max_samples = gr.Textbox(value="100000")
+        compute_type = gr.Radio(choices=["fp16", "bf16"], value="fp16")
 
     with gr.Row():
         batch_size = gr.Slider(value=4, minimum=1, maximum=512, step=1)
@@ -55,7 +55,8 @@ def create_train_tab(top_elems: Dict[str, "Component"], runner: "Runner") -> Dic
             logging_steps = gr.Slider(value=5, minimum=5, maximum=1000, step=5)
             save_steps = gr.Slider(value=100, minimum=10, maximum=5000, step=10)
             warmup_steps = gr.Slider(value=0, minimum=0, maximum=5000, step=1)
-            compute_type = gr.Radio(choices=["fp16", "bf16"], value="fp16")
+            flash_attn = gr.Checkbox(value=False)
+            rope_scaling = gr.Checkbox(value=False)
 
     with gr.Accordion(label="LoRA config", open=False) as lora_tab:
         with gr.Row():
@@ -107,11 +108,11 @@ def create_train_tab(top_elems: Dict[str, "Component"], runner: "Runner") -> Dic
         training_stage,
         dataset_dir,
         dataset,
-        max_source_length,
-        max_target_length,
+        cutoff_len,
         learning_rate,
         num_train_epochs,
         max_samples,
+        compute_type,
         batch_size,
         gradient_accumulation_steps,
         lr_scheduler_type,
@@ -120,7 +121,8 @@ def create_train_tab(top_elems: Dict[str, "Component"], runner: "Runner") -> Dic
         logging_steps,
         save_steps,
         warmup_steps,
-        compute_type,
+        flash_attn,
+        rope_scaling,
         lora_rank,
         lora_dropout,
         lora_target,
@@ -151,11 +153,11 @@ def create_train_tab(top_elems: Dict[str, "Component"], runner: "Runner") -> Dic
         preview_count=preview_count,
         preview_samples=preview_samples,
         close_btn=close_btn,
-        max_source_length=max_source_length,
-        max_target_length=max_target_length,
+        cutoff_len=cutoff_len,
         learning_rate=learning_rate,
         num_train_epochs=num_train_epochs,
         max_samples=max_samples,
+        compute_type=compute_type,
         batch_size=batch_size,
         gradient_accumulation_steps=gradient_accumulation_steps,
         lr_scheduler_type=lr_scheduler_type,
@@ -165,7 +167,8 @@ def create_train_tab(top_elems: Dict[str, "Component"], runner: "Runner") -> Dic
         logging_steps=logging_steps,
         save_steps=save_steps,
         warmup_steps=warmup_steps,
-        compute_type=compute_type,
+        flash_attn=flash_attn,
+        rope_scaling=rope_scaling,
         lora_tab=lora_tab,
         lora_rank=lora_rank,
         lora_dropout=lora_dropout,
diff --git a/src/llmtuner/webui/locales.py b/src/llmtuner/webui/locales.py
index 773ba03d..5ac3cd2e 100644
--- a/src/llmtuner/webui/locales.py
+++ b/src/llmtuner/webui/locales.py
@@ -147,26 +147,16 @@ LOCALES = {
             "value": "关闭"
         }
     },
-    "max_source_length": {
+    "cutoff_len": {
         "en": {
-            "label": "Max source length",
-            "info": "Max tokens in source sequence."
+            "label": "Cutoff length",
+            "info": "Max tokens in input sequence."
         },
         "zh": {
-            "label": "输入序列最大长度",
+            "label": "截断长度",
             "info": "输入序列分词后的最大长度。"
         }
     },
-    "max_target_length": {
-        "en": {
-            "label": "Max target length",
-            "info": "Max tokens in target sequence."
-        },
-        "zh": {
-            "label": "输出序列最大长度",
-            "info": "输出序列分词后的最大长度。"
-        }
-    },
     "learning_rate": {
         "en": {
             "label": "Learning rate",
@@ -197,6 +187,16 @@ LOCALES = {
             "info": "每个数据集最多使用的样本数。"
         }
     },
+    "compute_type": {
+        "en": {
+            "label": "Compute type",
+            "info": "Whether to use fp16 or bf16 mixed precision training."
+        },
+        "zh": {
+            "label": "计算类型",
+            "info": "是否启用 FP16 或 BF16 混合精度训练。"
+        }
+    },
     "batch_size": {
         "en": {
             "label": "Batch size",
@@ -277,14 +277,20 @@ LOCALES = {
             "info": "学习率预热采用的步数。"
         }
     },
-    "compute_type": {
+    "flash_attn": {
         "en": {
-            "label": "Compute type",
-            "info": "Whether to use fp16 or bf16 mixed precision training."
+            "label": "Use FlashAttention-2"
         },
         "zh": {
-            "label": "计算类型",
-            "info": "是否启用 FP16 或 BF16 混合精度训练。"
+            "label": "使用 FlashAttention-2"
+        }
+    },
+    "rope_scaling": {
+        "en": {
+            "label": "Use RoPE scaling"
+        },
+        "zh": {
+            "label": "使用 RoPE 插值"
         }
     },
     "lora_tab": {
diff --git a/src/llmtuner/webui/runner.py b/src/llmtuner/webui/runner.py
index f1df34e3..e2945158 100644
--- a/src/llmtuner/webui/runner.py
+++ b/src/llmtuner/webui/runner.py
@@ -73,11 +73,11 @@ class Runner:
         training_stage: str,
         dataset_dir: str,
         dataset: List[str],
-        max_source_length: int,
-        max_target_length: int,
+        cutoff_len: int,
         learning_rate: str,
         num_train_epochs: str,
         max_samples: str,
+        compute_type: str,
         batch_size: int,
         gradient_accumulation_steps: int,
         lr_scheduler_type: str,
@@ -86,7 +86,8 @@ class Runner:
         logging_steps: int,
         save_steps: int,
         warmup_steps: int,
-        compute_type: str,
+        flash_attn: bool,
+        rope_scaling: bool,
         lora_rank: int,
         lora_dropout: float,
         lora_target: str,
@@ -120,8 +121,7 @@ class Runner:
             system_prompt=system_prompt,
             dataset_dir=dataset_dir,
             dataset=",".join(dataset),
-            max_source_length=max_source_length,
-            max_target_length=max_target_length,
+            cutoff_len=cutoff_len,
             learning_rate=float(learning_rate),
             num_train_epochs=float(num_train_epochs),
             max_samples=int(max_samples),
@@ -132,6 +132,8 @@ class Runner:
             logging_steps=logging_steps,
             save_steps=save_steps,
             warmup_steps=warmup_steps,
+            flash_attn=flash_attn,
+            rope_scaling="linear" if rope_scaling else None,
             lora_rank=lora_rank,
             lora_dropout=lora_dropout,
             lora_target=lora_target or DEFAULT_MODULE.get(model_name.split("-")[0], "q_proj,v_proj"),
@@ -168,11 +170,13 @@ class Runner:
         system_prompt: str,
         dataset_dir: str,
         dataset: List[str],
-        max_source_length: int,
-        max_target_length: int,
+        cutoff_len: int,
         max_samples: str,
         batch_size: int,
-        predict: bool
+        predict: bool,
+        max_new_tokens: int,
+        top_p: float,
+        temperature: float
     ) -> Tuple[str, str, List[str], str, Dict[str, Any]]:
         if checkpoints:
             checkpoint_dir = ",".join(
@@ -200,10 +204,12 @@ class Runner:
             system_prompt=system_prompt,
             dataset_dir=dataset_dir,
             dataset=",".join(dataset),
-            max_source_length=max_source_length,
-            max_target_length=max_target_length,
+            cutoff_len=cutoff_len,
             max_samples=int(max_samples),
             per_device_eval_batch_size=batch_size,
+            max_new_tokens=max_new_tokens,
+            top_p=top_p,
+            temperature=temperature,
             output_dir=output_dir
         )