tree 304aa2acde5dbde3698c25ad7c7013312d79ff89
parent 08c3339e7c2f70978a52aaa6570945754f19952c
author Peter Bell <peterbell10@live.co.uk> 1589228397 -0700
committer Facebook GitHub Bot <facebook-github-bot@users.noreply.github.com> 1589228685 -0700

Lazily initialise thread local num_threads value (#37461)

Summary:
Fixes https://github.com/pytorch/pytorch/issues/37259, fixes https://github.com/pytorch/pytorch/issues/20156

This lazily calls `at::init_num_threads` once for each thread by adding a call to `lazy_init_num_threads` in `at::parallel_for` and `at::parallel_reduce`.

If this solution is okay, then we should add the same to guard other places that might use MKL or OpenMP.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/37461

Reviewed By: ezyang

Differential Revision: D21472763

Pulled By: ilia-cher

fbshipit-source-id: 889d6664f5bd4080037ade02ee324b1233992915