Summary:
give control of how often stats are printed, including jemalloc stats if enabled. Previously the default was 10 minutes so we'd only see updated stats for very long benchmark runs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4109
Differential Revision: D8796444
Pulled By: ajkr
fbshipit-source-id: fd7902fe3f105fae89322c4ab63316bba4a2b15e