Update run_batch interface and max_prefill_tokens (#574)

docs/test_process.md

 ## SRT Unit Tests
 
-### Low-level API
+### Latency Alignment
 ```
-cd sglang/test/srt/model
-
-python3 test_llama_low_api.py
-python3 test_llama_extend.py
-python3 test_llava_low_api.py
-python3 bench_llama_low_api.py
+python -m sglang.bench_latency --model-path meta-llama/Llama-2-7b-chat-hf --mem-fraction-static 0.8 --batch 32 --input-len 512 --output-len 256
 ```
 
 ### High-level API

python/sglang/lang/ir.py

@@ -120,6 +120,7 @@ class SglFunction:
         argspec = inspect.getfullargspec(func)
         assert argspec.args[0] == "s", 'The first argument must be "s"'
         self.arg_names = argspec.args[1:]
+        self.arg_defaults = argspec.defaults if argspec.defaults is not None else []
 
     def bind(self, **kwargs):
         assert all(key in self.arg_names for key in kwargs)
@@ -178,7 +179,18 @@ class SglFunction:
         assert isinstance(batch_kwargs, (list, tuple))
         if len(batch_kwargs) == 0:
             return []
-        assert isinstance(batch_kwargs[0], dict)
+        if not isinstance(batch_kwargs[0], dict):
+            num_programs = len(batch_kwargs)
+            # change the list of argument values to dict of arg_name -> arg_value
+            batch_kwargs = [
+                {self.arg_names[i]: v for i, v in enumerate(arg_values)}
+                for arg_values in batch_kwargs
+                if isinstance(arg_values, (list, tuple)) and
+                   len(self.arg_names) - len(self.arg_defaults) <= len(arg_values) <= len(self.arg_names)
+            ]
+            # Ensure to raise an exception if the number of arguments mismatch
+            if len(batch_kwargs) != num_programs:
+                raise Exception("Given arguments mismatch the SGL function signature")
 
         default_sampling_para = SglSamplingParams(
             max_new_tokens=max_new_tokens,

python/sglang/srt/managers/controller/tp_worker.py

@@ -98,10 +98,7 @@ class ModelTpServer:
             )
         self.max_total_num_tokens = self.model_runner.max_total_num_tokens
         self.max_prefill_tokens = (
-            max(
-                self.model_config.context_len,
-                min(self.max_total_num_tokens // 6, 32768),
-            )
+            4096
             if server_args.max_prefill_tokens is None
             else server_args.max_prefill_tokens
         )
@@ -371,8 +368,9 @@ class ModelTpServer:
             if (
                 req.extend_input_len + req.max_new_tokens() + new_batch_total_tokens
                 < available_size
-                and req.extend_input_len + new_batch_input_tokens
-                < self.max_prefill_tokens
+                and (req.extend_input_len + new_batch_input_tokens
+                <= self.max_prefill_tokens
+                or len(can_run_list) == 0)
             ):
                 delta = self.tree_cache.inc_lock_ref(req.last_node)
                 available_size += delta