def run(flags_obj):
"""Run ResNet ImageNet training and eval loop using native Keras APIs.
Args:
flags_obj: An object containing parsed flag values.
Raises:
ValueError: If fp16 is passed as it is not currently supported.
Returns:
Dictionary of training and eval stats.
"""
keras_utils.set_session_config(
enable_eager=flags_obj.enable_eager,
enable_xla=flags_obj.enable_xla)
# Execute flag override logic for better model performance
if flags_obj.tf_gpu_thread_mode:
keras_common.set_gpu_thread_mode_and_count(flags_obj)
if flags_obj.data_delay_prefetch:
keras_common.data_delay_prefetch()
keras_common.set_cudnn_batchnorm_mode()
dtype = flags_core.get_tf_dtype(flags_obj)
if dtype == 'float16':
policy = tf.keras.mixed_precision.experimental.Policy('infer_float32_vars')
tf.keras.mixed_precision.experimental.set_policy(policy)
data_format = flags_obj.data_format
if data_format is None:
data_format = ('channels_first'
if tf.test.is_built_with_cuda() else 'channels_last')
tf.keras.backend.set_image_data_format(data_format)
strategy = distribution_utils.get_distribution_strategy(
distribution_strategy=flags_obj.distribution_strategy,
num_gpus=flags_obj.num_gpus,
num_workers=distribution_utils.configure_cluster(),
all_reduce_alg=flags_obj.all_reduce_alg,
num_packs=flags_obj.num_packs)
if strategy:
# flags_obj.enable_get_next_as_optional controls whether enabling
# get_next_as_optional behavior in DistributedIterator. If true, last
# partial batch can be supported.
strategy.extended.experimental_enable_get_next_as_optional = (
flags_obj.enable_get_next_as_optional
)
strategy_scope = distribution_utils.get_strategy_scope(strategy)
# pylint: disable=protected-access
if flags_obj.use_synthetic_data:
distribution_utils.set_up_synthetic_data()
input_fn = keras_common.get_synth_input_fn(
height=imagenet_preprocessing.DEFAULT_IMAGE_SIZE,
width=imagenet_preprocessing.DEFAULT_IMAGE_SIZE,
num_channels=imagenet_preprocessing.NUM_CHANNELS,
num_classes=imagenet_preprocessing.NUM_CLASSES,
dtype=dtype,
drop_remainder=True)
else:
distribution_utils.undo_set_up_synthetic_data()
input_fn = imagenet_preprocessing.input_fn
# When `enable_xla` is True, we always drop the remainder of the batches
# in the dataset, as XLA-GPU doesn't support dynamic shapes.
drop_remainder = flags_obj.enable_xla
train_input_dataset = input_fn(
is_training=True,
data_dir=flags_obj.data_dir,
batch_size=flags_obj.batch_size,
num_epochs=flags_obj.train_epochs,
parse_record_fn=imagenet_preprocessing.parse_record,
datasets_num_private_threads=flags_obj.datasets_num_private_threads,
dtype=dtype,
drop_remainder=drop_remainder,
tf_data_experimental_slack=flags_obj.tf_data_experimental_slack,
)
eval_input_dataset = None
if not flags_obj.skip_eval:
eval_input_dataset = input_fn(
is_training=False,
data_dir=flags_obj.data_dir,
batch_size=flags_obj.batch_size,
num_epochs=flags_obj.train_epochs,
parse_record_fn=imagenet_preprocessing.parse_record,
dtype=dtype,
drop_remainder=drop_remainder)
lr_schedule = 0.1
if flags_obj.use_tensor_lr:
lr_schedule = keras_common.PiecewiseConstantDecayWithWarmup(
batch_size=flags_obj.batch_size,
epoch_size=imagenet_preprocessing.NUM_IMAGES['train'],
warmup_epochs=LR_SCHEDULE[0][1],
boundaries=list(p[1] for p in LR_SCHEDULE[1:]),
multipliers=list(p[0] for p in LR_SCHEDULE),
compute_lr_on_cpu=True)
with strategy_scope:
optimizer = keras_common.get_optimizer(lr_schedule)
if dtype == 'float16':
# TODO(reedwm): Remove manually wrapping optimizer once mixed precision
# can be enabled with a single line of code.
optimizer = tf.keras.mixed_precision.experimental.LossScaleOptimizer(
optimizer, loss_scale=flags_core.get_loss_scale(flags_obj,
default_for_fp16=128))
if flags_obj.use_trivial_model:
model = trivial_model.trivial_model(
imagenet_preprocessing.NUM_CLASSES, dtype)
else:
model = resnet_model.resnet50(
num_classes=imagenet_preprocessing.NUM_CLASSES, dtype=dtype)
model.compile(
loss='sparse_categorical_crossentropy',
optimizer=optimizer,
metrics=(['sparse_categorical_accuracy']
if flags_obj.report_accuracy_metrics else None),
run_eagerly=flags_obj.run_eagerly,
experimental_run_tf_function=flags_obj.force_v2_in_keras_compile)
callbacks = keras_common.get_callbacks(
learning_rate_schedule, imagenet_preprocessing.NUM_IMAGES['train'])
train_steps = (
imagenet_preprocessing.NUM_IMAGES['train'] // flags_obj.batch_size)
train_epochs = flags_obj.train_epochs
if flags_obj.train_steps:
train_steps = min(flags_obj.train_steps, train_steps)
train_epochs = 1
num_eval_steps = (
imagenet_preprocessing.NUM_IMAGES['validation'] // flags_obj.batch_size)
validation_data = eval_input_dataset
if flags_obj.skip_eval:
# Only build the training graph. This reduces memory usage introduced by
# control flow ops in layers that have different implementations for
# training and inference (e.g., batch norm).
if flags_obj.set_learning_phase_to_train:
# TODO(haoyuzhang): Understand slowdown of setting learning phase when
# not using distribution strategy.
tf.keras.backend.set_learning_phase(1)
num_eval_steps = None
validation_data = None
if not strategy and flags_obj.explicit_gpu_placement:
# TODO(b/135607227): Add device scope automatically in Keras training loop
# when not using distribition strategy.
no_dist_strat_device = tf.device('/device:GPU:0')
no_dist_strat_device.__enter__()
history = model.fit(train_input_dataset,
epochs=train_epochs,
steps_per_epoch=train_steps,
callbacks=callbacks,
validation_steps=num_eval_steps,
validation_data=validation_data,
validation_freq=flags_obj.epochs_between_evals,
verbose=2)
eval_output = None
if not flags_obj.skip_eval:
eval_output = model.evaluate(eval_input_dataset,
steps=num_eval_steps,
verbose=2)
if not strategy and flags_obj.explicit_gpu_placement:
no_dist_strat_device.__exit__()
stats = keras_common.build_stats(history, eval_output, callbacks)
return stats
def run(flags_obj):
"""Run ResNet ImageNet training and eval loop using native Keras APIs.
Args:
flags_obj: An object containing parsed flag values.
Raises:
ValueError: If fp16 is passed as it is not currently supported.
Returns:
Dictionary of training and eval stats.
"""
# TODO(tobyboyd): Remove eager flag when tf 1.0 testing ends.
# Eager is default in tf 2.0 and should not be toggled
if keras_common.is_v2_0():
keras_common.set_config_v2()
else:
config = keras_common.get_config_proto_v1()
if flags_obj.enable_eager:
tf.compat.v1.enable_eager_execution(config=config)
else:
sess = tf.Session(config=config)
tf.keras.backend.set_session(sess)
# Execute flag override logic for better model performance
if flags_obj.tf_gpu_thread_mode:
keras_common.set_gpu_thread_mode_and_count(flags_obj)
if flags_obj.data_delay_prefetch:
keras_common.data_delay_prefetch()
keras_common.set_cudnn_batchnorm_mode()
dtype = flags_core.get_tf_dtype(flags_obj)
if dtype == 'float16':
policy = tf.keras.mixed_precision.experimental.Policy(
'infer_float32_vars')
tf.keras.mixed_precision.experimental.set_policy(policy)
data_format = flags_obj.data_format
if data_format is None:
data_format = ('channels_first'
if tf.test.is_built_with_cuda() else 'channels_last')
tf.keras.backend.set_image_data_format(data_format)
strategy = distribution_utils.get_distribution_strategy(
distribution_strategy=flags_obj.distribution_strategy,
num_gpus=flags_obj.num_gpus,
num_workers=distribution_utils.configure_cluster(),
all_reduce_alg=flags_obj.all_reduce_alg,
num_packs=flags_obj.num_packs)
# flags_obj.enable_get_next_as_optional controls whether enabling
# get_next_as_optional behavior in DistributedIterator. If true, last partial
# batch can be supported.
strategy.extended.experimental_enable_get_next_as_optional = (
flags_obj.enable_get_next_as_optional)
strategy_scope = distribution_utils.get_strategy_scope(strategy)
# pylint: disable=protected-access
if flags_obj.use_synthetic_data:
distribution_utils.set_up_synthetic_data()
input_fn = keras_common.get_synth_input_fn(
height=imagenet_main.DEFAULT_IMAGE_SIZE,
width=imagenet_main.DEFAULT_IMAGE_SIZE,
num_channels=imagenet_main.NUM_CHANNELS,
num_classes=imagenet_main.NUM_CLASSES,
dtype=dtype,
drop_remainder=True)
else:
distribution_utils.undo_set_up_synthetic_data()
input_fn = imagenet_main.input_fn
# When `enable_xla` is True, we always drop the remainder of the batches
# in the dataset, as XLA-GPU doesn't support dynamic shapes.
drop_remainder = flags_obj.enable_xla
train_input_dataset = input_fn(
is_training=True,
data_dir=flags_obj.data_dir,
batch_size=flags_obj.batch_size,
num_epochs=flags_obj.train_epochs,
parse_record_fn=parse_record_keras,
datasets_num_private_threads=flags_obj.datasets_num_private_threads,
dtype=dtype,
drop_remainder=drop_remainder,
tf_data_experimental_slack=flags_obj.tf_data_experimental_slack,
)
eval_input_dataset = None
if not flags_obj.skip_eval:
eval_input_dataset = input_fn(is_training=False,
data_dir=flags_obj.data_dir,
batch_size=flags_obj.batch_size,
num_epochs=flags_obj.train_epochs,
parse_record_fn=parse_record_keras,
dtype=dtype,
drop_remainder=drop_remainder)
lr_schedule = 0.1
if flags_obj.use_tensor_lr:
lr_schedule = keras_common.PiecewiseConstantDecayWithWarmup(
batch_size=flags_obj.batch_size,
epoch_size=imagenet_main.NUM_IMAGES['train'],
warmup_epochs=LR_SCHEDULE[0][1],
boundaries=list(p[1] for p in LR_SCHEDULE[1:]),
multipliers=list(p[0] for p in LR_SCHEDULE),
compute_lr_on_cpu=True)
with strategy_scope:
optimizer = keras_common.get_optimizer(lr_schedule)
if dtype == 'float16':
# TODO(reedwm): Remove manually wrapping optimizer once mixed precision
# can be enabled with a single line of code.
optimizer = tf.keras.mixed_precision.experimental.LossScaleOptimizer(
optimizer, loss_scale=flags_core.get_loss_scale(flags_obj))
if flags_obj.enable_xla and not flags_obj.enable_eager:
# TODO(b/129861005): Fix OOM issue in eager mode when setting
# `batch_size` in keras.Input layer.
if strategy and strategy.num_replicas_in_sync > 1:
# TODO(b/129791381): Specify `input_layer_batch_size` value in
# DistributionStrategy multi-replica case.
input_layer_batch_size = None
else:
input_layer_batch_size = flags_obj.batch_size
else:
input_layer_batch_size = None
if flags_obj.use_trivial_model:
model = trivial_model.trivial_model(imagenet_main.NUM_CLASSES,
dtype)
else:
model = resnet_model.resnet50(
num_classes=imagenet_main.NUM_CLASSES,
dtype=dtype,
batch_size=input_layer_batch_size)
model.compile(loss='sparse_categorical_crossentropy',
optimizer=optimizer,
metrics=(['sparse_categorical_accuracy']
if flags_obj.report_accuracy_metrics else None),
cloning=flags_obj.clone_model_in_keras_dist_strat)
callbacks = keras_common.get_callbacks(learning_rate_schedule,
imagenet_main.NUM_IMAGES['train'])
train_steps = imagenet_main.NUM_IMAGES['train'] // flags_obj.batch_size
train_epochs = flags_obj.train_epochs
if flags_obj.train_steps:
train_steps = min(flags_obj.train_steps, train_steps)
train_epochs = 1
num_eval_steps = (imagenet_main.NUM_IMAGES['validation'] //
flags_obj.batch_size)
validation_data = eval_input_dataset
if flags_obj.skip_eval:
# Only build the training graph. This reduces memory usage introduced by
# control flow ops in layers that have different implementations for
# training and inference (e.g., batch norm).
tf.keras.backend.set_learning_phase(1)
num_eval_steps = None
validation_data = None
history = model.fit(train_input_dataset,
epochs=train_epochs,
steps_per_epoch=train_steps,
callbacks=callbacks,
validation_steps=num_eval_steps,
validation_data=validation_data,
validation_freq=flags_obj.epochs_between_evals,
verbose=2)
eval_output = None
if not flags_obj.skip_eval:
eval_output = model.evaluate(eval_input_dataset,
steps=num_eval_steps,
verbose=2)
stats = keras_common.build_stats(history, eval_output, callbacks)
return stats