Python tf.config.set_logical_device_configuration用法及代码示例

为 tf.config.PhysicalDevice 设置逻辑设备配置。

用法

tf.config.set_logical_device_configuration(
    device, logical_devices
)

一旦初始化运行时，可见的tf.config.PhysicalDevice 默认情况下将有一个与之关联的tf.config.LogicalDevice。指定 tf.config.LogicalDeviceConfiguration 对象列表允许在同一个 tf.config.PhysicalDevice 上创建多个设备。

只要运行时未初始化，就可以通过调用此函数来修改逻辑设备配置。运行时初始化后调用此函数会引发 RuntimeError。

以下示例将 CPU 拆分为 2 个逻辑设备：

physical_devices = tf.config.list_physical_devices('CPU')
assert len(physical_devices) == 1, "No CPUs found"
# Specify 2 virtual CPUs. Note currently memory limit is not supported.
try:
  tf.config.set_logical_device_configuration(
    physical_devices[0],
    [tf.config.LogicalDeviceConfiguration(),
     tf.config.LogicalDeviceConfiguration()])
  logical_devices = tf.config.list_logical_devices('CPU')
  assert len(logical_devices) == 2

  tf.config.set_logical_device_configuration(
    physical_devices[0],
    [tf.config.LogicalDeviceConfiguration(),
     tf.config.LogicalDeviceConfiguration(),
     tf.config.LogicalDeviceConfiguration(),
     tf.config.LogicalDeviceConfiguration()])
except:
  # Cannot modify logical devices once initialized.
  pass

以下示例将 GPU 拆分为 2 个逻辑设备，每个设备 100 MB：

physical_devices = tf.config.list_physical_devices('GPU')
try:
  tf.config.set_logical_device_configuration(
    physical_devices[0],
    [tf.config.LogicalDeviceConfiguration(memory_limit=100),
     tf.config.LogicalDeviceConfiguration(memory_limit=100)])

  logical_devices = tf.config.list_logical_devices('GPU')
  assert len(logical_devices) == len(physical_devices) + 1

  tf.config.set_logical_device_configuration(
    physical_devices[0],
    [tf.config.LogicalDeviceConfiguration(memory_limit=10),
     tf.config.LogicalDeviceConfiguration(memory_limit=10)])
except:
  # Invalid device or cannot modify logical devices once initialized.
  pass