lightning/pytorch_lightning/accelerators/cpu.py

70 lines
2.4 KiB
Python

# Copyright The PyTorch Lightning team.
#
# 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.
from typing import Any, Dict, List, Union
import torch
from pytorch_lightning.accelerators.accelerator import Accelerator
from pytorch_lightning.utilities.exceptions import MisconfigurationException
from pytorch_lightning.utilities.rank_zero import rank_zero_warn
from pytorch_lightning.utilities.types import _DEVICE
class CPUAccelerator(Accelerator):
"""Accelerator for CPU devices."""
def setup_environment(self, root_device: torch.device) -> None:
"""
Raises:
MisconfigurationException:
If the selected device is not CPU.
"""
super().setup_environment(root_device)
if root_device.type != "cpu":
raise MisconfigurationException(f"Device should be CPU, got {root_device} instead.")
def get_device_stats(self, device: _DEVICE) -> Dict[str, Any]:
"""CPU device stats aren't supported yet."""
return {}
@staticmethod
def parse_devices(devices: Union[int, str, List[int]]) -> Union[int, str, List[int]]:
"""Accelerator device parsing logic."""
return devices
@staticmethod
def get_parallel_devices(devices: Union[int, str, List[int]]) -> List[torch.device]:
"""Gets parallel devices for the Accelerator."""
if isinstance(devices, int):
return [torch.device("cpu")] * devices
rank_zero_warn(
f"The flag `devices` must be an int with `accelerator='cpu'`, got `devices={devices!r}` instead."
)
return []
@staticmethod
def auto_device_count() -> int:
"""Get the devices when set to auto."""
return 1
@staticmethod
def is_available() -> bool:
"""CPU is always available for execution."""
return True
@staticmethod
def name() -> str:
"""Name of the Accelerator."""
return "cpu"