auto_lr_find does not support DDP. We set the multiprocessing context based on the number of workers. This leads to a scenario where a user cannot use auto_lr_find with multiple workers, even though this would be possible if the multiprocessing context were set to None.
A couple options:
infer the multiprocessing context based on number of GPUs instead of number of workers
allow the user to explicitly set the multiprocessing context
do not support multiprocessing until PTL supports this for auto lr find
auto_lr_finddoes not support DDP. We set the multiprocessing context based on the number of workers. This leads to a scenario where a user cannot useauto_lr_findwith multiple workers, even though this would be possible if the multiprocessing context were set to None.A couple options: