I want to use nccl2 as distributed backend.
I just downloaded nccl2 from nccl nvidia download page 1.

nvidia-machine-learning-repo-ubuntu1604_1.0.0-1_amd64.deb
nccl-repo-ubuntu1604-2.2.13-ga-cuda8.0_1-1_amd64.deb

Please provide some instructions for using nccl backend for DistributedDataParallel.