diff --git a/python/examples/imdb/benchmark_batch.py b/python/examples/imdb/benchmark_batch.py
index 99b8ec56ca74e72cb58d81f3a55b0fe7c19e4902..57ee6816989d4a807a328342f188a7298b7772de 100644
--- a/python/examples/imdb/benchmark_batch.py
+++ b/python/examples/imdb/benchmark_batch.py
@@ -64,4 +64,4 @@ result = multi_thread_runner.run(single_func, args.thread, {})
 avg_cost = 0
 for cost in result[0]:
     avg_cost += cost
-print("total cost of each thread".format(avg_cost / args.thread))
+print("total cost {} s of each thread".format(avg_cost / args.thread))
diff --git a/python/paddle_serving_server_gpu/__init__.py b/python/paddle_serving_server_gpu/__init__.py
index 6f0ece74eeccc40eaf9676738e15e7b52b9da9ce..93a167b949cfaaabf900aba5c6f1376e9568ca60 100644
--- a/python/paddle_serving_server_gpu/__init__.py
+++ b/python/paddle_serving_server_gpu/__init__.py
@@ -116,7 +116,7 @@ class Server(object):
         self.reload_interval_s = 10
         self.module_path = os.path.dirname(paddle_serving_server.__file__)
         self.cur_path = os.getcwd()
-        self.check_cuda
+        self.check_cuda()
         self.use_local_bin = False
         self.gpuid = 0
 
@@ -144,7 +144,7 @@ class Server(object):
             self.bin_path = os.environ["SERVING_BIN"]
 
     def check_cuda(self):
-        r = os.system("whereis cuda")
+        r = os.system("whereis cuda > /dev/null")
         if r != 0:
             raise SystemExit(
                 "CUDA not found, please check your environment or use cpu version by \"pip install paddle_serving_server\""