pytorch

a08fc1a7 - allow users to set sample rate and add per iteration latency breakdowns (#53145)

allow users to set sample rate and add per iteration latency breakdowns (#53145) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/53145 add a new API to allow users to set sample rate for runtime stats, also add per iteration latency breakdowns to DDPLoggingData struct. e.g. if users set sample rate to be 1, they can analyze per iteration latency change over time (not avged) ghstack-source-id: 123443369 Test Plan: unit test Reviewed By: SciPioneer Differential Revision: D26763957 fbshipit-source-id: baff6a09c2a590e6eb91362ca6f47ae8fa6ddb0e