Re: Back-patch use of unnamed POSIX semaphores for Linux?

On Wed, Dec 7, 2016 at 3:42 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:

>
>
> Hmm ... after further experimentation, I still can't get this version of
> systemd (231) to do anything evil.  It turns out that Fedora ships it with
> KillUserProcesses turned off by default, and maybe having that on is a
> prerequisite for the other behavior?  But that doesn't make a lot of sense
> because we'd never be seeing the reports of databases moaning about lost
> semaphores if the processes got killed first.  Anyway, I see nothing bad
> happening if KillUserProcesses is off, while if it's on then the database
> gets shut down reasonably politely via SIGTERM.
>
> Color me confused ... maybe systemd's behavior has changed?
>

Hrm, the following incantation seems to break for me on a fresh Fedora 25
system:
1) As root su to $USER and start postgres.
2) ssh in as $USER and then logout
3) # psql localhost

FATAL: semctl(4980742, 3, SETVAL, 0) failed: Invalid argument
LOG: server process (PID 14569) exited with exit code 1
...