Fix latency benchmark (#557)

benchmark/latency_throughput/test_latency.py

 import argparse
-import random
 import time
 
 import requests
@@ -9,6 +8,7 @@ if __name__ == "__main__":
     parser.add_argument("--host", type=str, default="http://127.0.0.1")
     parser.add_argument("--port", type=int, default=None)
     parser.add_argument("--backend", type=str, default="srt")
+    parser.add_argument("--max-tokens", type=int, default=256)
     args = parser.parse_args()
 
     if args.port is None:
@@ -25,7 +25,7 @@ if __name__ == "__main__":
 
     url = f"{args.host}:{args.port}"
     a = 20
-    max_new_tokens = 256
+    max_new_tokens = args.max_tokens
     prompt = f"{a, }"
 
     tic = time.time()
@@ -37,6 +37,7 @@ if __name__ == "__main__":
                 "sampling_params": {
                     "temperature": 0,
                     "max_new_tokens": max_new_tokens,
+                    "ignore_eos": True,
                 },
             },
         )
@@ -48,6 +49,7 @@ if __name__ == "__main__":
                 "parameters": {
                     "temperature": 0,
                     "max_new_tokens": max_new_tokens,
+                    "ignore_eos": True,
                 },
             },
         )
@@ -58,6 +60,7 @@ if __name__ == "__main__":
                 "prompt": prompt,
                 "temperature": 0,
                 "max_tokens": max_new_tokens,
+                "ignore_eos": True,
             },
         )
     elif args.backend == "ginfer":