SingleDeviceStrategy¶

class lightning.pytorch.strategies.SingleDeviceStrategy(device='cpu', accelerator=None, checkpoint_io=None, precision_plugin=None)[source]¶

Bases: Strategy

Strategy that handles communication on a single device.

all_gather(tensor, group=None, sync_grads=False)[source]¶

Perform a all_gather on all processes.

Return type: Tensor

barrier(*args, **kwargs)[source]¶

Synchronizes all processes which blocks processes until the whole group enters this function.

Parameters: name¶ – an optional name to pass into barrier.
Return type: None

broadcast(obj, src=0)[source]¶

Broadcasts an object to all processes.

Parameters

obj¶ (TypeVar(TBroadcast)) – the object to broadcast
src¶ (int) – source rank

Return type

TypeVar(TBroadcast)

model_to_device()[source]¶

Moves the model to the correct device.

Return type: None

reduce(tensor, *args, **kwargs)[source]¶

Reduces a tensor from several distributed processes to one aggregated tensor. As this plugin only operates with a single device, the reduction is simply the identity.

Parameters

tensor¶ (Any | Tensor) – the tensor to sync and reduce
*args¶ – ignored
**kwargs¶ – ignored

Return type

Any | Tensor

Returns

the unmodified input as reduction is not needed for single process operation

setup(trainer)[source]¶

Setup plugins for the trainer fit and creates optimizers.

Parameters: trainer¶ (Trainer) – the trainer instance
Return type: None

property is_global_zero: bool¶

Whether the current process is the rank zero process not only on the local node, but for all nodes.

Return type: bool

property root_device: device¶

Returns the root device.

Return type: device