Disable systemd-oomd by default
As described by Fedora, lacking an ability of Xfce to spawn desktop processes in cgroups, systemd-oomd should be disabled by default; otherwise, one runaway process kills an entire user session. The minimum alternative of the Linux OOM Killer would at least allow Alt+SysRq+f
.
How will this work if everything is in the same cgroup?
It will not work as systemd-oomd acts on a per-cgroup level. Applications will need to spawn processes into separate cgroups (e.g. with systemd-run) or use a desktop environment (e.g. GNOME, KDE) that does this for them.
Should spins that don't put processes in separate cgroups be excluded from this change?
That will be left up to the maintainers of those spins. Based on feedback, the current plan is to enable systemd-oomd with the specified configuration by default to minimize fragmentation on the Fedora install base (the Upgrade/Compatibility section as been updated to reflect this). A separate subpackage, "systemd-oomd-defaults", controls the policy for systemd-oomd and excluding it or removing it (and performing a systemctl daemon-reload) will prevent systemd-oomd from killing anything; without a policy systemd-oomd doesn't act.