STT-tensorflow/tensorflow/python/distribute/test_util.py
Xinyi Wang a7467d5d51 Adding new APIs under tf.distribute: gather and all_gather.
`tf.distribute.Strategy.gather` and `tf.distribute.ReplicaContext.all_gather` methods are APIs to gather and concatenate `tf.distribute.DistributedValues` object(s) across workers and devices. They are counterparts in cross-replica context and replica context. This methods are implemented for all strategies except ParameterServerStrategy.

PiperOrigin-RevId: 337972679
Change-Id: I1d61c96b830683da135d5b4e89da29693c51262c
2020-10-19 18:09:08 -07:00

98 lines
3.7 KiB
Python

# Copyright 2020 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
"""Test utilities."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import functools
from tensorflow.python.compat import v2_compat
from tensorflow.python.distribute import collective_all_reduce_strategy
from tensorflow.python.distribute import multi_process_runner
from tensorflow.python.distribute import values
from tensorflow.python.eager import context
from tensorflow.python.framework import config
from tensorflow.python.framework import ops
from tensorflow.python.ops import array_ops
from tensorflow.python.util import nest
def gather(strategy, value):
"""Gathers value from all workers.
This is intended for tests before we implement an official all-gather API.
Args:
strategy: a `tf.distribute.Strategy`.
value: a nested structure of n-dim `tf.distribute.DistributedValue` of
`tf.Tensor`, or of a `tf.Tensor` if the strategy only has one replica.
Cannot contain tf.sparse.SparseTensor.
Returns:
a (n+1)-dim `tf.Tensor`.
"""
return nest.map_structure(functools.partial(_gather, strategy), value)
def _gather(strategy, value):
"""Gathers a single value."""
# pylint: disable=protected-access
if not isinstance(value, values.DistributedValues):
value = values.PerReplica([ops.convert_to_tensor(value)])
if not isinstance(strategy.extended,
collective_all_reduce_strategy.CollectiveAllReduceExtended):
return array_ops.stack(value._values)
assert len(strategy.extended.worker_devices) == len(value._values)
inputs = [array_ops.expand_dims_v2(v, axis=0) for v in value._values]
return strategy.gather(values.PerReplica(inputs), axis=0)
# pylint: enable=protected-access
def set_logical_devices_to_at_least(device, num):
"""Create logical devices of at least a given number."""
if num < 1:
raise ValueError("`num` must be at least 1 not %r" % (num,))
physical_devices = config.list_physical_devices(device)
if not physical_devices:
raise RuntimeError("No {} found".format(device))
if len(physical_devices) >= num:
return
# By default each physical device corresponds to one logical device. We create
# multiple logical devices for the last physical device so that we have `num`
# logical devices.
num = num - len(physical_devices) + 1
logical_devices = []
for _ in range(num):
if device.upper() == "GPU":
logical_devices.append(
context.LogicalDeviceConfiguration(memory_limit=2048))
else:
logical_devices.append(context.LogicalDeviceConfiguration())
# Create logical devices from the the last device since sometimes the first
# GPU is the primary graphic card and may has less memory available.
config.set_logical_device_configuration(physical_devices[-1], logical_devices)
def main(enable_v2_behavior=True):
"""All-in-one main function for tf.distribute tests."""
if enable_v2_behavior:
v2_compat.enable_v2_behavior()
else:
v2_compat.disable_v2_behavior()
# TODO(b/131360402): configure default logical devices.
multi_process_runner.test_main()