lightning/pytorch_lightning/plugins/precision/deepspeed_precision.py

89 lines
2.9 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
from torch import Tensor
from torch.nn import Module
from torch.optim import Optimizer
import pytorch_lightning as pl
from pytorch_lightning.plugins.precision.precision_plugin import PrecisionPlugin
from pytorch_lightning.utilities import GradClipAlgorithmType
from pytorch_lightning.utilities.model_helpers import is_overridden
from pytorch_lightning.utilities.warnings import WarningCache
warning_cache = WarningCache()
class DeepSpeedPrecisionPlugin(PrecisionPlugin):
""" Precision plugin for DeepSpeed integration. """
def __init__(self, precision: int) -> None:
super().__init__()
self.precision = precision
def pre_optimizer_step(
self,
pl_module: 'pl.LightningModule',
optimizer: Optimizer,
optimizer_idx: int,
lambda_closure: Callable,
**kwargs: Any,
) -> bool:
deepspeed_engine = pl_module.trainer.model
# DeepSpeed not support closures.
lambda_closure()
if not pl_module.automatic_optimization:
pl_module.trainer.call_hook("on_after_backward")
deepspeed_engine.step()
return False
def backward(
self,
model: 'pl.LightningModule',
closure_loss: Tensor,
optimizer: Optimizer,
opt_idx: int,
should_accumulate: bool,
*args: Any,
**kwargs: Any,
) -> Tensor:
if is_overridden('backward', model):
warning_cache.warn(
"Overridden backward hook in the LightningModule will be ignored since DeepSpeed handles"
"backward logic outside of the LightningModule"
)
# todo: hack around for deepspeed engine to call backward
deepspeed_engine = model.trainer.model
deepspeed_engine.backward(closure_loss, *args, **kwargs)
# once backward has been applied, release graph
closure_loss = closure_loss.detach()
return closure_loss
def clip_gradients(
self,
optimizer: Optimizer,
clip_val: Union[int, float],
gradient_clip_algorithm: GradClipAlgorithmType = GradClipAlgorithmType.NORM,
model: Optional[Module] = None,
) -> None:
"""
DeepSpeed handles clipping gradients internally via the training type plugin.
"""
pass