Horton

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

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Alex Hunsaker <badalex@gmail.com>, Robert Haas <robertmhaas@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2016-12-07T23:49:57Z
Lists: pgsql-hackers 
Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> Tom Lane wrote:
>> Color me confused ... maybe systemd's behavior has changed?

> https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/ZNQW72UP36UAFMX53HPFFQTWTQDZVJ3M/

I see Lennart hasn't gotten any less convinced that he's always right
since I left Red Hat :-(

But anyway, it's a demonstrable fact that Fedora 25 has KillUserProcesses
off by default, even though it contains systemd-231.  I assume FESCO
brought down the hammer at some point.

This still doesn't address the real question, which is whether RemoveIPC
does anything if KillUserProcesses is off, and whether that behavior
has changed.  I don't see anything about RemoveIPC in that thread.

			regards, tom lane

Commits

  1. Make the different Unix-y semaphore implementations ABI-compatible.

  2. Use unnamed POSIX semaphores, if available, on Linux and FreeBSD.