Disabling find_unused_parameters
When trying to disable find_unused_parameters in the trainer by doing the following,
strategy=DDPStrategy(find_unused_parameters=False)
Am being thrown an import error for from pytorch_lightning.strategies import DDPStrategy
Error:
No module named 'pytorch_lightning.strategies'
pytorch_lightning.strategies will be available in v1.6 release and is only available in master at the moment.
For now, you can use:
from pytorch_lightning.plugins import DDPPlugin

trainer = pl.Trainer(
    ...,
    strategy=DDPPlugin(find_unused_parameters=False),
)

See the stable version of docs (not latest) here: https://pytorch-lightning.readthedocs.io/en/stable/guides/speed.html?highlight=find_unused_parameters#when-using-ddp-plugins-set-find-unused-parameters-false