pytorch

1f04a00c - [PyTorch Distributed] Update documentation about NCCL environment variables (#74006)

[PyTorch Distributed] Update documentation about NCCL environment variables (#74006) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/74006 updated recommendations about environment variables to use during debug and performance tuning Test Plan: `make html` Reviewed By: rohan-varma Differential Revision: D34767454 fbshipit-source-id: 08cd58469bf72b58702e50e82020fa19b43b5911 (cherry picked from commit ac7e6630f8043f85d3d16be17c6a8ad1ebb2990c)