GitLab

* zero-1 memory fix

* auto-tune max elems per comm to reduce padding/comm intervals

* clean-up and added previously missing reduction options

* fix testing backing to work with torch1.7

Co-authored-by: Jeff Rasley <jerasley@microsoft.com>

Updates for ZeRO stage 2 + ZeRO stage 1 w. RS
Co-authored-by: Tunji Ruwase <olruwase@microsoft.com>
Co-authored-by: Samyam Rajbhandari <samyamr@microsoft.com>
Co-authored-by: Shaden Smith <ShadenTSmith@gmail.com>
Co-authored-by: Elton Zheng <eltonz@microsoft.com>
Co-authored-by: Shaden Smith <Shaden.Smith@microsoft.com>
Co-authored-by: yuxionghe <yuxhe@microsoft.com>
Co-authored-by: Arash Ashari <arashari@microsoft.com>

* Enables NCCL backend in @distributed_test

* Adds pytest-forked to avoid CUDA re-initialization issue.

* paste typo

* transcription typo

* add allreduce test

* comment out set rank to cuda for now

* switched back to gloo

* Adds distributed_test decorator and some unit tests.

* Setting NCCL backend.

* Parametrizes test.

* rank -> local_rank

* Temporarily disable CUDA initialization.