lightning/pytorch_lightning/accelerators/cpu.py

40 lines
1.6 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.
import pytorch_lightning as pl
from pytorch_lightning.accelerators.accelerator import Accelerator
from pytorch_lightning.plugins.precision import MixedPrecisionPlugin
from pytorch_lightning.utilities.exceptions import MisconfigurationException
class CPUAccelerator(Accelerator):
""" Accelerator for CPU devices. """
def setup(self, trainer: 'pl.Trainer', model: 'pl.LightningModule') -> None:
"""
Raises:
MisconfigurationException:
If AMP is used with CPU, or if the selected device is not CPU.
"""
if isinstance(self.precision_plugin, MixedPrecisionPlugin):
raise MisconfigurationException(
" Mixed precision is currenty only supported with the AMP backend"
" and AMP + CPU is not supported. Please use a GPU option or"
" change precision setting."
)
if "cpu" not in str(self.root_device):
raise MisconfigurationException(f"Device should be CPU, got {self.root_device} instead.")
return super().setup(trainer, model)