Incorrect IPC advice for OpenBSD
Hackorum builds and tests every patch posted to the lists, not only commitfest submissions. This is Hackorum's own CI rather than the PostgreSQL project's, and it is still under testing - please report anything that looks wrong.
You can run a PostgreSQL built from this patch straight from Docker, with no checkout and no build:
docker run --rm -p 5432:5432 ghcr.io/hackorum-dev/postgres-patch:t76241psql -h localhost -U postgresBuilt from patchset v1 (message #1), July 27, 2026 at 08:31 PM.
Every patchset is also pushed to a branch of our PostgreSQL fork, so you can check out the same tree CI built. Without a PostgreSQL checkout:
git clone --branch t76241_1 https://github.com/hackorum-dev/postgres.gitIn a checkout you already have, add the fork once:
git remote add hackorum https://github.com/hackorum-dev/postgres.gitthen, for this patchset and every later one:
git fetch hackorum t76241_1 && git checkout t76241_1Patchset v1 (message #1) is on t76241_1
The OpenBSD paragraph in the "Shared Memory and Semaphores” section seems to
have been slightly incorrect since around 2002. The kern.ipc.shm_use_phys
sysctl setting has never existed in OpenBSD (it is in NetBSD and FreeBSD) and
SEMMAP is not a kernel configuration option. Further, there is no kernel
config for locking shared memory into RAM so the whole paragraph is best
removed it seems. I believe this is an artifact from FreeBSD and OpenBSD
sharing a paragraph, which was split into separate ones a long time ago.
The attached patch removes the above mentioned parts (confirmed with an OpenBSD
developer). This should probably be backpatched to all supported versions as
it’s been wrong for a long time.
cheers ./daniel
On Wed, May 16, 2018 at 10:45 PM, Daniel Gustafsson <daniel@yesql.se> wrote:
The OpenBSD paragraph in the "Shared Memory and Semaphores” section seems
to
have been slightly incorrect since around 2002. The kern.ipc.shm_use_phys
sysctl setting has never existed in OpenBSD (it is in NetBSD and FreeBSD)
and
SEMMAP is not a kernel configuration option. Further, there is no kernel
config for locking shared memory into RAM so the whole paragraph is best
removed it seems. I believe this is an artifact from FreeBSD and OpenBSD
sharing a paragraph, which was split into separate ones a long time ago.The attached patch removes the above mentioned parts (confirmed with an
OpenBSD
developer). This should probably be backpatched to all supported versions
as
it’s been wrong for a long time.
Applied and backpatched. Thanks!
--
Magnus Hagander
Me: https://www.hagander.net/ <http://www.hagander.net/>
Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>