Fix syncbn (#29013)

* fix syncbn

* add unittest

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

@@ -228,9 +228,15 @@ class TestConvertSyncBatchNorm(unittest.TestCase):
 
         with program_guard(Program(), Program()):
             compare_model = paddle.nn.Sequential(
-                paddle.nn.Conv2D(3, 5, 3), paddle.nn.BatchNorm2D(5))
+                paddle.nn.Conv2D(3, 5, 3),
+                paddle.nn.BatchNorm2D(5), paddle.nn.BatchNorm2D(5))
             model = paddle.nn.Sequential(
-                paddle.nn.Conv2D(3, 5, 3), paddle.nn.BatchNorm2D(5))
+                paddle.nn.Conv2D(3, 5, 3),
+                paddle.nn.BatchNorm2D(5),
+                paddle.nn.BatchNorm2D(
+                    5,
+                    weight_attr=fluid.ParamAttr(name='bn.scale'),
+                    bias_attr=fluid.ParamAttr(name='bn.bias')))
             model = paddle.nn.SyncBatchNorm.convert_sync_batchnorm(model)
             for idx, sublayer in enumerate(compare_model.sublayers()):
                 if isinstance(sublayer, paddle.nn.BatchNorm2D):

python/paddle/nn/layer/norm.py

@@ -1103,6 +1103,13 @@ class SyncBatchNorm(_BatchNormBase):
         """
         layer_output = layer
         if isinstance(layer, _BatchNormBase):
+            if layer._weight_attr != None and not isinstance(layer._weight_attr,
+                                                             bool):
+                layer._weight_attr.name = layer._weight_attr.name + '_sync'
+            if layer._bias_attr != None and not isinstance(layer._weight_attr,
+                                                           bool):
+                layer._bias_attr.name = layer._bias_attr.name + '_sync'
+
             layer_output = SyncBatchNorm(layer._num_features, layer._momentum,
                                          layer._epsilon, layer._weight_attr,
                                          layer._bias_attr, layer._data_format,