Re: Vacuuming the operating system documentation

On Sun, Jun 7, 2020 at 3:42 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Thomas Munro <thomas(dot)munro(at)gmail(dot)com> writes:
> > Yeah, I wasn't planning on changing anything in backbranches. It
> > sounds like we're OK with doing this for 13. Here's a version with a
> > few more changes:
>
> Looks pretty good to me. I attach a delta patch with a few more
> proposed adjustments. Notably, I made the wording about /etc/sysctl.conf
> for Linux match that for other OSes, except I said "see" not
> "modify" because (at least on my Red Hat based installations)
> the comments in /etc/sysctl.conf direct you to modify various
> sub-files.

Thanks. Pushed.

One more thing I spotted, post commit: the example symptom of
systemd's RemoveIPC feature trashing your cluster is an error from
semctl(), but that can't happen anymore on a standard build. Not sure
what to put in its place... I guess the remaining symptoms would be
(1) the little "interlock" shmem segment is unregistered, which is
probably symptom-free (until you start a second postmaster in the same
pgdata), and (2) POSIX shm objects getting unlinked underneath a
parallel query. That's probably what this build farm animal was
telling me:

https://www.postgresql.org/message-id/CA+hUKG+t40GoUczAhQsRhxWeS=fsZXpObyojboUTN6BEOfUj4Q@mail.gmail.com