fix random failed on GPU test=develop (#25293)

python/paddle/fluid/tests/unittests/dygraph_to_static/test_cycle_gan.py

@@ -32,6 +32,10 @@ import unittest
 import numpy as np
 from PIL import Image, ImageOps
 
+import os
+# Use GPU:0 to elimate the influence of other tasks.
+os.environ["CUDA_VISIBLE_DEVICES"] = "1"
+
 import paddle
 import paddle.fluid as fluid
 from paddle.fluid.dygraph import to_variable, declarative, ProgramTranslator
@@ -327,6 +331,11 @@ class conv2d(fluid.dygraph.Layer):
                 initializer=fluid.initializer.NormalInitializer(
                     loc=0.0, scale=stddev)),
             bias_attr=con_bias_attr)
+        # Note(Aurelius84): The calculation of GPU kernel in BN is non-deterministic, 
+        # failure rate is 1/100 in Dev but seems incremental in CE platform.
+        # If on GPU, we disable BN temporarily.
+        if fluid.is_compiled_with_cuda():
+            norm = False
         if norm:
             self.bn = BatchNorm(
                 use_global_stats=True,  # set True to use deterministic algorithm
@@ -383,6 +392,8 @@ class DeConv2D(fluid.dygraph.Layer):
                 initializer=fluid.initializer.NormalInitializer(
                     loc=0.0, scale=stddev)),
             bias_attr=de_bias_attr)
+        if fluid.is_compiled_with_cuda():
+            norm = False
         if norm:
             self.bn = BatchNorm(
                 use_global_stats=True,  # set True to use deterministic algorithm
@@ -606,8 +617,16 @@ class TestCycleGANModel(unittest.TestCase):
     def test_train(self):
         st_out = self.train(to_static=True)
         dy_out = self.train(to_static=False)
+
+        assert_func = np.allclose
+        # Note(Aurelius84): Because we disable BN on GPU, 
+        # but here we enhance the check on CPU by `np.array_equal`
+        # which means the dy_out and st_out shall be exactly same.
+        if not fluid.is_compiled_with_cuda():
+            assert_func = np.array_equal
+
         self.assertTrue(
-            np.allclose(dy_out, st_out),
+            assert_func(dy_out, st_out),
             msg="dy_out:\n {}\n st_out:\n{}".format(dy_out, st_out))