[Speculative Decoding][MTP] Support static CacheKV C8 quantization and optimize memory usage (#5155)

* support static cachekv c8 quantization in mtp mode

* optimize memory allocation

fastdeploy/config.py

@@ -198,6 +198,8 @@ class ModelConfig:
         self.pooler_config: Optional["PoolerConfig"] = field(init=False)
         self.override_pooler_config: Optional[Union[dict, "PoolerConfig"]] = None
         self.revision = None
+        self.prefix_layer_name = "layers"
+        self.kv_cache_quant_scale_path = ""
 
         self.partial_rotary_factor: float = 1.0
         self.num_nextn_predict_layers = 0
@@ -244,6 +246,7 @@ class ModelConfig:
 
         self.enable_mm = is_multimodal_model
 
+        self.kv_cache_quant_scale_path = os.path.join(self.model, "kv_cache_scale.json")
         if self.runner_type == "pooling":
             os.environ["FD_USE_GET_SAVE_OUTPUT_V1"] = "1"
 
@@ -1589,6 +1592,10 @@ class FDConfig:
                 else:
                     self.scheduler_config.max_num_batched_tokens = self.model_config.max_model_len
 
+        self.scheduler_config.max_chunk_len = (
+            self.scheduler_config.max_num_batched_tokens + self.scheduler_config.max_extra_num_batched_tokens
+        )
+
         if self.long_prefill_token_threshold == 0:
             self.long_prefill_token_threshold = int(self.model_config.max_model_len * 0.04)