Re: Problem with PostgreSQL 18 and semaphores

[Marc Baudoin <babafou%babafou.eu.org@localhost>]

Martin Husemann <martin%duskware.de@localhost> écrit :
> On Sun, Oct 26, 2025 at 11:59:17AM +0100, Marc Baudoin wrote:
> > So I believe those should be raised (for 11.0 and 10.2) because
> > PostgreSQL should be able to run out of the box on NetBSD.
> 
> It is not that simple and Postgres is an exception and not run on most
> NetBSD systems.
> 
> The problem is that the allocation is static and requires wired kernel
> memory. Just bumping up the numbers will waste lots of this resourse
> (which is quite scare on some architectures).

How much more than usally exactly?

> What we could do short-term is to modify the postgres message #ifdef
> __NetBSD__ and point to a man page describing the details. The sysctls
> seem to not be documented besides their own description (sysctl -d) and
> sysctl(7). Maybe sem_open(3) should get a paragraph about the issue and
> suggestions how to work around when the system hits the limit?

A MESSAGE file in the postgresql18-server package would probably
be enough so people would be aware of what to do before trying to
start PostgreSQL.