Incorrect IPC advice for OpenBSD
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
Attachments:
openbsd_ipc.patchapplication/octet-stream; name=openbsd_ipc.patch; x-unix-mode=0644Download+0-8
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/>