pytorch

7314f1c2 - [torch/multiprocessing] Update documentation indicating that start_method is ignored for mp.spawn() (#33070)

[torch/multiprocessing] Update documentation indicating that start_method is ignored for mp.spawn() (#33070) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/33070 `start_method` parameter is intentionally ignored for `mp.spawn()`. Document this fact and point the user to `start_processes` if they want to use a different `start_method`. Test Plan: Warning message looks like: ``` main.py:8: UserWarning: This method only supports start_method=spawn (got: fork). To use a different start_method use: torch.multiprocessing.start_process(...) warnings.warn(msg) ``` Reviewed By: ailzhang Differential Revision: D19780235 fbshipit-source-id: 4599cd18c3ba6cc401810efe4f390290ffa8023b