reduce iter time to reduce exec time (#26388)

python/paddle/fluid/tests/unittests/parallel_executor_test_base.py

@@ -34,7 +34,7 @@ class TestParallelExecutorBase(unittest.TestCase):
     def check_network_convergence(cls,
                                   method,
                                   use_cuda=True,
-                                  iter=50,
+                                  iter=5,
                                   batch_size=None,
                                   feed_dict=None,
                                   feed_data_reader=None,

python/paddle/fluid/tests/unittests/seresnext_net.py

@@ -179,7 +179,7 @@ def batch_size(use_cuda):
 def iter(use_cuda):
     if use_cuda:
         return 10
-    return 2
+    return 1
 
 
 gpu_img, gpu_label = init_data(