lightning/pytorch_lightning/trainer/auto_mix_precision.py

44 lines
1.8 KiB
Python

from abc import ABC
from pytorch_lightning import _logger as log
from pytorch_lightning.utilities import APEX_AVAILABLE, NATIVE_AMP_AVALAIBLE, rank_zero_warn, AMPType
class TrainerAMPMixin(ABC):
# this is just a summary on variables used in this abstract class,
# the proper values/initialisation should be done in child class
precision: int
def _setup_amp_backend(self, amp_type: str):
if self.precision != 16:
# no AMP requested, so we can leave now
return
amp_type = amp_type.lower()
assert amp_type in ('native', 'apex'), f'Unsupported amp type {amp_type}'
if amp_type == 'native':
if not NATIVE_AMP_AVALAIBLE:
rank_zero_warn('You have asked for native AMP but your PyTorch version does not support it.'
' Consider upgrading with `pip install torch>=1.6`.'
' We will attempt to use NVIDIA Apex for this session.')
amp_type = 'apex'
else:
log.info('Using native 16bit precision.')
self.amp_backend = AMPType.NATIVE
if amp_type == 'apex':
if not APEX_AVAILABLE:
rank_zero_warn('You have asked for Apex AMP but you have not installed it yet.'
' Install apex first using this guide: https://github.com/NVIDIA/apex#linux')
else:
log.info('Using APEX 16bit precision.')
self.amp_backend = AMPType.APEX
if not self.amp_backend:
raise ModuleNotFoundError(
f'You have asked for AMP support {amp_type}, but there is no support on your side yet.'
f' Consider installing torch >= 1.6 or NVIDIA Apex.'
)
@property
def use_amp(self) -> bool:
return self.precision == 16