Source code for composer.algorithms.channels_last.channels_last
# Copyright 2021 MosaicML. All Rights Reserved.
from __future__ import annotations
import logging
from typing import Optional
import torch
from composer.core import Algorithm, Event, State
from composer.loggers import Logger
log = logging.getLogger(__name__)
[docs]def apply_channels_last(model: torch.nn.Module) -> None:
"""Changes the memory format of the model to torch.channels_last.
This usually yields improved GPU utilization.
Args:
model: model or module to modify
"""
model.to(memory_format=torch.channels_last) # type: ignore
[docs]class ChannelsLast(Algorithm):
"""Changes the memory format of the model to ``torch.channels_last``. This usually yields improved GPU utilization.
Runs on ``Event.INIT``, so it can set the memory format before the model is DDP wrapped. Has no hyperparameters.
"""
[docs] def match(self, event: Event, state: State) -> bool:
"""Runs on ``Event.INIT``"""
del state # unused
return event == Event.INIT
[docs] def apply(self, event: Event, state: State, logger: Logger) -> Optional[int]:
"""Changes the memory format of the model to ``torch.channels_last``"""
del event, logger # unused
# TODO: Double check model is moved to cuda with device type
apply_channels_last(state.model)
log.info(f'Model {state.model.__class__.__name__} changed to channels_last format.')