spurious out of swap kills

[Mark Millard]

bob prohaska fbsd at www.zefox.net wrote on
Fri Sep 13 16:24:57 UTC 2019 :

> Not sure this is relevant, but in compiling chromium on a Pi3 with 6 GB
> of swap the job completed successfully some months ago, with peak swap 
> use around 3.5 GB. The swap layout was sub-optimal, with a 2 GB partition
> combined with a 4 GB partition. A little over 4GB total seems usable. 
> 
> A few days ago the same attempt stopped with a series of OOMA kills,
> but in each case simply restarting allowed the compile to pick up
> where it left off and continue, eventually finishing with a runnable
> version of chromium. In this case swap use peaked a little over 4 GB.
> 
> Might this suggest the machine isn't freeing swap in a timely manner?

Are you saying that your increases to:

vm.pageout_oom_seq

no longer prove sufficient? What value for vm.pageout_oom_seq were
you using that got the recent failures?

(Mark Johnston's slow_swap.diff patch [and related] for investigations
of some OOM killing contributions never became official and has not
been updated to apply to updated code. It has been over a year since
those patches were used for the arm small board computer investigations
that lead to my learning about vm.pageout_oom_seq .)

If more or different configuration/tuning is required, I'm going to
eventually want to learn about it as well.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)