Re: killed: out of swap

[David Brownlee <abs%absd.org@localhost>]

On Tue, 14 Jun 2022 at 13:33, Robert Elz <kre%munnari.oz.au@localhost> wrote:
>
> NetBSD implements overcommitted swap - many processes malloc()
> (or mmap() which that really becomes in the current implementation)
> far more memory than they're ever going to actually use.  It is only
> when some real physical memory is required (rather than simply a marker
> "zero filled page might be required here") that the system actually
> allocates any real resources.   Similarly pages mapped from a file only
> need swap space if they're altered - otherwise the file serves as the
> backing store for it.
>
> Once upon a time there was a method to turn overcommitted swap off, and
> require actual allocations (of RAM or swap) to be made for all reserved
> (virtual) memory.  I used to enable that all the time - but I haven't seen
> any mention of it in ages, and the mechanism might no longer still exist.

What might be interesting is a way to influence the order in which
processes are chosen to kill...

David