fix unequal session_len of turbomind and pipeline

lmdeploy/turbomind/deploy/target_model/base.py

@@ -14,7 +14,6 @@
 from pydantic.dataclasses import dataclass
 
 from lmdeploy.messages import TurbomindEngineConfig
-from lmdeploy.model import MODELS
 
 from ..source_model.base import BaseInputModel, BaseReader
 
@@ -165,9 +164,11 @@ def __init__(self,
     def get_config(self, cfg: TurbomindModelConfig) -> TurbomindModelConfig:
         """Generate turbomind model config (config.ini)."""
         _, bos_id, eos_id = self.input_model.tokenizer_info()
-        model_info = self.input_model.model_info()
-        session_len = model_info.get('max_position_embeddings',
-                                     MODELS.get(cfg.model_name)().session_len)
+        from transformers import AutoConfig
+        hf_config = AutoConfig.from_pretrained(self.input_model.model_path,
+                                               trust_remote_code=True)
+        from lmdeploy.utils import _get_and_verify_max_len
+        session_len = _get_and_verify_max_len(hf_config, self.cfg.session_len)
         final_cfg = cfg.__dict__
         final_cfg.update(
             dict(start_id=bos_id, end_id=eos_id, session_len=session_len + 8))

lmdeploy/turbomind/turbomind.py

@@ -271,9 +271,6 @@ def _from_hf(self, model_source: ModelSource, model_path: str,
             input_model=input_model, cfg=cfg, to_file=False, out_dir='')
 
         cfg = output_model.cfg
-        if engine_config.session_len is not None:
-            cfg.session_len = engine_config.session_len
-
         cfg.update_prefill_conifg(engine_config)
         self.model_name = cfg.model_name
         self.config = cfg

lmdeploy/utils.py

@@ -268,6 +268,11 @@ def _get_and_verify_max_len(
     max_model_len: Optional[int],
 ) -> int:
     """Get and verify the model's maximum length."""
+    if not isinstance(hf_tm_config, PretrainedConfig) and \
+            hasattr(hf_tm_config, 'session_len'):
+        # turbomind backend already has session_len
+        return getattr(hf_tm_config, 'session_len')
+
     logger = get_logger('lmdeploy')
     derived_max_model_len = float('inf')
     possible_keys = [