Source code for pytorch_lightning.plugins.precision.sharded_native_amp
# 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.
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from typing import Optional, Union
import torch
from pytorch_lightning.overrides.fairscale import _FAIRSCALE_AVAILABLE
from pytorch_lightning.plugins.precision.native_amp import NativeMixedPrecisionPlugin
from pytorch_lightning.utilities.exceptions import MisconfigurationException
if _FAIRSCALE_AVAILABLE:
from fairscale.optim import OSS
from fairscale.optim.grad_scaler import ShardedGradScaler
else:
OSS = ShardedGradScaler = object
[docs]class ShardedNativeMixedPrecisionPlugin(NativeMixedPrecisionPlugin):
"""Native AMP for Sharded Training."""
def __init__(
self, precision: Union[str, int], device: str, scaler: Optional[torch.cuda.amp.GradScaler] = None
) -> None:
if not _FAIRSCALE_AVAILABLE:
raise MisconfigurationException(
"You have asked for sharded AMP but you have not installed it."
" Install `fairscale` using this guide: https://https://github.com/facebookresearch/fairscale"
)
super().__init__(precision, device, scaler=ShardedGradScaler() if scaler is None and precision == 16 else None)
[docs] def clip_grad_by_norm(self, optimizer: "OSS", clip_val: Union[int, float]) -> None:
optimizer.clip_grad_norm(clip_val)