Should we improve "PID XXXX is not a PostgreSQL server process" warning for pg_terminate_backend(<<postmaster_pid>>)?

Hi,

pg_terminate_backend and pg_cancel_backend with postmaster PID produce
"PID XXXX is not a PostgresSQL server process" warning [1], which
basically implies that the postmaster is not a PostgreSQL process at
all. This is a bit misleading because the postmaster is the parent of
all PostgreSQL processes. Should we improve the warning message if the
given PID is postmasters' PID?

If yes, how about a generic message for both of the functions -
"signalling postmaster process is not allowed" or "cannot signal
postmaster process" or some other better suggestion?

[1] 2471176 ---> is postmaster PID.
postgres=# select pg_terminate_backend(2471176);
WARNING: PID 2471176 is not a PostgreSQL server process
pg_terminate_backend
----------------------
f
(1 row)
postgres=# select pg_cancel_backend(2471176);
WARNING: PID 2471176 is not a PostgreSQL server process
pg_cancel_backend
-------------------
f
(1 row)

With Regards,
Bharath Rupireddy.
EnterpriseDB: http://www.enterprisedb.com