systemd: Introduce systemd-oomd conf

[EliasTheGrandMasterOfMistakes]

oomd.conf define a systemd oomd conf, service can
be enabled manually by user when enable
systemctl enable --now systemd-oomd

Based on https://www.reddit.com/r/archlinux/comments/mk2lg6/how_to_properly_configure_systemdoomd/?rdt=56355

Is possible too for separate it in a new package and enable this service in it.
A oomd.conf.d/ can be too prefered if be necessary

[ventureoo]

I'm not against it, but, unfortunately, we offer in repositories kernels with PRJC schedulers that don't support PSI, which uses systemd-oomd to monitor the system load, so I'm not sure if we should enable that by default in cachyos-settings package.

[1Naim]

so I'm not sure if we should enable that by default in cachyos-settings package

Not familiar with systemd-oomd so I need to look through some documentation to see what the conf is doing, but we could include the conf (if it's good) and just have systemd-oomd as an optional service to enable, i.e. what we have right now.

[ptr1337]

Personally im fine with it.

Yes, prjc does need PSI, but not many users are using bmq and also would require additonal enabling of the service.

[EliasTheGrandMasterOfMistakes]

I'm not against it, but, unfortunately, we offer in repositories kernels with PRJC schedulers that don't support PSI, which uses systemd-oomd to monitor the system load, so I'm not sure if we should enable that by default in cachyos-settings package.

can be good to warning first like a new doc page just to explain in details systemd-oomd?

[EliasTheGrandMasterOfMistakes]

so I'm not sure if we should enable that by default in cachyos-settings package

Not familiar with systemd-oomd so I need to look through some documentation to see what the conf is doing, but we could include the conf (if it's good) and just have systemd-oomd as an optional service to enable, i.e. what we have right now.

i'm not familiar too, but this reddit tip has worked for me
ManagedOOMMemoryPressure=kill is used to set default behaviour to kill in memory pressure threshold iirc.
ManagedOOMMemoryPressureLimit=70% is for memory pressure threshold limit usage, i has changed to 70% instead 50% to be not much agressive.
on manager looks that
DefaultCPUAccounting=yes
DefaultIOAccounting=yes
DefaultMemoryAccounting=yes
DefaultTasksAccounting=yes
is for accounting task for systemd-oomd i think is used cgroup for these
and for
SwapUsedLimitPercent=90%
DefaultMemoryPressureDurationSec=20s
i has changed to just 90% of swap to not be much agressive

[EliasTheGrandMasterOfMistakes]

Personally im fine with it.

Yes, prjc does need PSI, but not many users are using bmq and also would require additonal enabling of the service.

Thank you

[notpentadactyl]

after fzf made me go oom today, I'm all for this!

edit: that being said using this config, this command still gets me oom: systemd-run --user tail /dev/zero and nothing is getting killed. Unsure if I'm doing it wrong?!

[EliasTheGrandMasterOfMistakes]

after fzf made me go oom today, I'm all for this!

edit: that being said using this config, this command still gets me oom: systemd-run --user tail /dev/zero and nothing is getting killed. Unsure if I'm doing it wrong?!

you have enable sudo systemctl enable --now systemd-oomd.service?

[notpentadactyl]

after fzf made me go oom today, I'm all for this!
edit: that being said using this config, this command still gets me oom: systemd-run --user tail /dev/zero and nothing is getting killed. Unsure if I'm doing it wrong?!

you have enable sudo systemctl enable --now systemd-oomd.service?

Yes, I had it enabled, I also disabled and re-enabled it now, then I tried: systemd-run --user tail /dev/zero

At that point I did killall tail to not run out.

[EliasTheGrandMasterOfMistakes]

er tail /d

your system ram is really big, i think if you leave for some time the systemd-oomd will kill it but you can try with defaults from second comment in reddit

ManagedOOMMemoryPressure=kill
ManagedOOMMemoryPressureLimit=50%

you can try too:
DefaultOOMPolicy=kill