Adds a -m flag to pytorch.distributed.launch (#24910)
Summary:
Adds a '-m' flag to torch.distributed.launch that allows users to launch python modules using launch instead of specifying the full file path.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/24910
Differential Revision: D17221653
Pulled By: pietern
fbshipit-source-id: 5c6453ed266fd121103b11caab303e3f9404227d
