This might be nitpicking (or i'm currently missing something), but i recognized
that setting wal_buffers = -1 always triggers the following on reload, even if
nothing to wal_buffers had changed:
$ pg_ctl reload
LOG: received SIGHUP, reloading configuration files
LOG: parameter "wal_buffers" cannot be changed without restarting the server
This only happens when you have wal_buffers set to -1.
--
Thanks
Bernd