Re: number of semaphores and semaphore sets

Robert Haas wrote:
> On Mon, Mar 21, 2011 at 12:05 PM, Anton Yuzhaninov <citrin(at)citrin(dot)ru> wrote:
> > This page:
> > http://www.postgresql.org/docs/9.0/interactive/kernel-resources.html
> >
> > has formula:
> > ceil((max_connections + autovacuum_max_workers) / 16)
> >
> > for number of semaphore sets (identifiers).
> >
> > It seems to be wrong (outdated).
> >
> > Correct formula seems to be
> >
> > ceil((max_connections + autovacuum_max_workers + 4) / 16)
> >
> > Semaphore sets created in src/backend/storage/lmgr/proc.c:
> > 1. MaxConnections
> > 2. autovacuum_max_workers + 1
> > 3. NUM_AUXILIARY_PROCS (currently 3)
>
> Yeah, I think you're right. It appears that nothing material has
> changed here since 8.3, so I'm inclined to back-patch this doc fix
> back that far.
>
> Barring objections, I'll go change this.

I have applied the attached patch and backpatched it to 9.0 and 9.1.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +