lightning/pytorch_lightning/accelerators/gpu_accelerator.py

109 lines
3.4 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, Callable, Optional, Union
import torch
from pytorch_lightning.accelerators.accelerator import Accelerator, ReduceOp
from pytorch_lightning.cluster_environments import ClusterEnvironment
from pytorch_lightning.distributed.dist import LightningDistributed
from pytorch_lightning.utilities import AMPType
class GPUAccelerator(Accelerator):
amp_backend: AMPType
def __init__(self, trainer, cluster_environment: Optional[ClusterEnvironment] = None):
"""
Runs training using a single GPU
Example::
# default
trainer = Trainer(accelerator=GPUAccelerator())
"""
super().__init__(trainer, cluster_environment)
self.dist = LightningDistributed()
self.nickname = None
def setup(self, model):
# call setup
self.trainer.call_setup_hook(model)
torch.cuda.set_device(self.trainer.root_gpu)
model.cuda(self.trainer.root_gpu)
# CHOOSE OPTIMIZER
# allow for lr schedulers as well
self.setup_optimizers(model)
# 16-bit
model = self.trainer.precision_connector.connect(model)
self.trainer.convert_to_lightning_optimizers()
self.trainer.model = model
def train(self):
model = self.trainer.model
# set up training routine
self.trainer.train_loop.setup_training(model)
# train or test
results = self.train_or_test()
return results
def _step(self, model_step: Callable, args):
args[0] = self.to_device(args[0])
if self.trainer.amp_backend == AMPType.NATIVE:
with torch.cuda.amp.autocast():
output = model_step(*args)
else:
output = model_step(*args)
return output
def training_step(self, args):
return self._step(self.trainer.model.training_step, args)
def validation_step(self, args):
return self._step(self.trainer.model.validation_step, args)
def test_step(self, args):
return self._step(self.trainer.model.test_step, args)
def to_device(self, batch):
gpu_id = 0
if isinstance(self.trainer.data_parallel_device_ids, list):
gpu_id = self.trainer.data_parallel_device_ids[0]
# Don't copy the batch since there is a single gpu that the batch could
# be referenced from and if there are multiple optimizers the batch will
# wind up copying it to the same device repeatedly.
return self.batch_to_device(batch, gpu_id)
def sync_tensor(self,
tensor: Union[torch.Tensor],
group: Optional[Any] = None,
reduce_op: Optional[Union[ReduceOp, str]] = None) -> torch.Tensor:
return tensor
@property
def require_distributed_sampler(self):
return False