Run multi-gpu (single host) resnet50 and resnext101 training in bench (#18043)
Summary:
This is now working in rocm 2.2
cc xw285cornell
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18043
Differential Revision: D14477493
Pulled By: bddppq
fbshipit-source-id: 4d2dab1d5dbdbd4d6189162c074b19c4e9882c7d
