[systemd-devel] how to let systemd hibernate start/stop the swap area?

[Lennart Poettering]

On Fr, 31.03.23 07:57, Michael Chapman (mike at very.puzzling.org) wrote:

> On Fri, 31 Mar 2023, Luca Boccassi wrote:
> [...]
> > No, it does not make "little difference", there are entire subsystems
> > which are much worse off, if not completely useless, without swap.
> > Post-cgroupsv2 memory controller things are considerably different on
> > this front, and old "common wisdom" no longer applies.
>
> What are some examples here?
>
> What specifically is the difference between:
>
> * swap does not exist at all;
> * swap is full of data that will not be swapped in for weeks or
>   months;

The big difference is that the RAM that became available because the
unused stuff was swapped out has been applied to better uses,
i.e. keep more frequently used stuff around, improving performance of
the often used stuff, at the price of degrading peformance of the
apparently never used stuff. Overall win!

Lennart

--
Lennart Poettering, Berlin