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Set the logical device configuration for a tf.config.PhysicalDevice
.
tf.config.set_logical_device_configuration(
device, logical_devices
)
A visible tf.config.PhysicalDevice
will by default have a single
tf.config.LogicalDevice
associated with it once the runtime is initialized.
Specifying a list of tf.config.LogicalDeviceConfiguration
objects allows
multiple devices to be created on the same tf.config.PhysicalDevice
.
Logical device configurations can be modified by calling this function as long as the runtime is uninitialized. After the runtime is initialized calling this function raises a RuntimeError.
The following example splits the CPU into 2 logical devices:
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
The following example splits the GPU into 2 logical devices with 100 MB each:
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
Args | |
---|---|
device
|
The PhysicalDevice to configure.
|
logical_devices
|
(optional) List of tf.config.LogicalDeviceConfiguration
objects to allocate for the specified PhysicalDevice . If None, the
default configuration will be used.
|
Raises | |
---|---|
ValueError
|
If argument validation fails. |
RuntimeError
|
Runtime is already initialized. |