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.