Fix the default chunked prefill size (#2268)

python/sglang/srt/model_executor/model_runner.py

@@ -118,7 +118,7 @@ class ModelRunner:
             logger.info(
                 "Automatically turn off --chunked-prefill-size and adjust --mem-fraction-static for multimodal models."
             )
-            server_args.chunked_prefill_size = None
+            server_args.chunked_prefill_size = -1
             self.mem_fraction_static *= 0.95
             # TODO: qwen2-vl does not support radix cache now, set disable_radix_cache=True automatically
             if self.model_config.hf_config.architectures == [
@@ -148,12 +148,14 @@ class ModelRunner:
 
         set_cpu_offload_max_bytes(int(server_args.cpu_offload_gb * 1024**3))
 
-        # Init components
+        # Get memory before model loading
         min_per_gpu_memory = self.init_torch_distributed()
+
+        # Load the model
         self.sampler = Sampler()
         self.load_model()
 
-        # Apply torch TP if model supports it
+        # Apply torch TP if the model supports it
         supports_torch_tp = getattr(self.model, "supports_torch_tp", False)
         if self.tp_size > 1 and supports_torch_tp:
             self.apply_torch_tp()
@@ -161,6 +163,7 @@ class ModelRunner:
         else:
             self.torch_tp_applied = False
 
+        # Init memory pool and attention backends
         if server_args.lora_paths is not None:
             self.init_lora_manager()
         self.init_memory_pool(