protecting some processes from out-of-swap killer

[David Magda]

On Tue, April 28, 2015 05:51, Ronald Klop wrote:

> The OS trying to kill a process is probably not what you want. So when you
> protect(1) postgres the OS will kill another process, which I hope is not
> running without reason.
> My advice would be to
> - or increase your swap space
> - or tune postgresql to use less memory
> - or limit tmpfs (tmpfs uses swap if RAM is short)
> - or tune zfs to use less memory

Personally I didn't even know FreeBSD had an OOM killer. I regularly run
into Linux's though, but that's because by default Linux allows
over-committing of memory.

I was under the impression that FreeBSD did not over-subscribe memory, and
so would not allow a process to do a malloc() unless there was enough
RAM+swap to satisfy it.

Is this a mistaken assumption? (I probably have to buy the McKusick,
Neville-Neil, Watson book.)