While reading the code in this area this morning, I noticed that wal_log_hints and track_commit_timestamp are not mentioned in the desc routine of XLOG_CHANGE_PARAMETER. Also, it is not mentioned in postgresql.conf.sample that a value update of wal_log_hints requires a system restart.
In order to fix those things, attached are two patches:
- patch 1 should be applied back to 9.4 where wal_log_hints has been added
- patch 2 is master-only, and needs to be applied on top of patch 1.