[TUHS] VM over-commit (and the OOM killers)

[Tom Lyon]

The counterpoint to "just say no to swapping" is that sometimes you really,
really, want a job to proceed even if at a glacial pace.

Some years ago I had to do a Linux kernel build on a 1GB(maybe less?) MIPS
system, and even though it had oodles of swap space, the OOM killer kept
biting.
Turns out you have to tune "swappiness" in poorly documented ways to get
Linux to actually use virtual memory.    I think the build took about a
week once it worked.

On Fri, Feb 28, 2025 at 8:04 AM Dennis Boone <drb at msu.edu> wrote:

>  > I’m probably a lost soul on this issue, but swap space is just a way
>  > to turn program bugs into performance problems.
>
> You're hardly the only one.  Some years ago, running Linux web and
> database servers, I quit creating swap space.  A runaway program would
> turn the system into an infinite game of shuffle-the-pages well before
> the OOM killer actually decided to kill something, and in that state,
> one couldn't even reboot.  This expanded the time window of "broken"
> from tens of seconds, and perhaps a service restart, into tens of
> minutes and a power button recovery.  Every #$%^&* time.
>
> De
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tuhs.org/pipermail/tuhs/attachments/20250228/1551d356/attachment.htm>