dynamo_timed: Add a log_waitcounter option. (#141402)
Summary:
This logs a waitcounter of the name pytorch.dynamo_timed.{key}.
Primarily sending this now to make sure everyone likes the API, then
I'll add tests, and migrate one dynamo_timed to use it. (likely starting
with
https://github.com/pytorch/pytorch/pull/141379).
Testing is a bit harder, since we don't normally have any way to read
_WaitCounter state AFAICT. I want to poke around and see if I can figure
out a way to read the state, otherwise I'll just mock it to at least
make sure it's mostly working.
X-link: https://github.com/pytorch/pytorch/pull/141402
Approved by: https://github.com/jamesjwu, https://github.com/masnesral
Reviewed By: atalman
Differential Revision: D66729166
Pulled By: c00w
fbshipit-source-id: cec031ead8e83e0cc7dc31435b9cc3c69744a29c
