fix no attribute 'per_replica_batch_size' (#8406)

research/deep_speech/deep_speech.py

@@ -209,6 +209,35 @@ def generate_dataset(data_dir):
   speech_dataset = dataset.DeepSpeechDataset(train_data_conf)
   return speech_dataset
 
+def per_device_batch_size(batch_size, num_gpus):
+  """For multi-gpu, batch-size must be a multiple of the number of GPUs.
+
+
+  Note that distribution strategy handles this automatically when used with
+  Keras. For using with Estimator, we need to get per GPU batch.
+
+  Args:
+    batch_size: Global batch size to be divided among devices. This should be
+      equal to num_gpus times the single-GPU batch_size for multi-gpu training.
+    num_gpus: How many GPUs are used with DistributionStrategies.
+
+  Returns:
+    Batch size per device.
+
+  Raises:
+    ValueError: if batch_size is not divisible by number of devices
+  """
+  if num_gpus <= 1:
+    return batch_size
+
+  remainder = batch_size % num_gpus
+  if remainder:
+    err = ('When running with multiple GPUs, batch size '
+           'must be a multiple of the number of available GPUs. Found {} '
+           'GPUs with a batch size of {}; try --batch_size={} instead.'
+          ).format(num_gpus, batch_size, batch_size - remainder)
+    raise ValueError(err)
+  return int(batch_size / num_gpus)
 
 def run_deep_speech(_):
   """Run deep speech training and eval loop."""
@@ -257,8 +286,7 @@ def run_deep_speech(_):
       model_dir=flags_obj.model_dir,
       batch_size=flags_obj.batch_size)
 
-  per_replica_batch_size = distribution_utils.per_replica_batch_size(
-      flags_obj.batch_size, num_gpus)
+  per_replica_batch_size = per_device_batch_size(flags_obj.batch_size, num_gpus)
 
   def input_fn_train():
     return dataset.input_fn(