ORG.FREEDESKTOP.OOM1(5) org.freedesktop.oom1 ORG.FREEDESKTOP.OOM1(5)

org.freedesktop.oom1 - The D-Bus interface of systemd-oomd

systemd-oomd.service(8) is a system service which implements a userspace out-of-memory (OOM) killer. This page describes the D-Bus interface.

The service exposes the following interfaces on the Manager object on the bus:

node /org/freedesktop/oom1 {
  interface org.freedesktop.oom1.Manager {
    methods:
      DumpByFileDescriptor(out h fd);
    signals:
      Killed(s cgroup,
             s reason);
  };
  interface org.freedesktop.DBus.Peer { ... };
  interface org.freedesktop.DBus.Introspectable { ... };
  interface org.freedesktop.DBus.Properties { ... };
};

Killed() signal is sent when any cgroup is killed by oomd.

Note that more reasons will be added in the future, and the table below will be expanded accordingly.

Table 1. Killing reasons

Reason Description
memory-used Application took too much memory and swap.
memory-pressure Application took enough memory and swap to cause sufficient slowdown of other applications.

These D-Bus interfaces follow
the usual interface versioning guidelines[1].

Killed() was added in version 252.

1.
the usual interface versioning guidelines
https://0pointer.de/blog/projects/versioning-dbus.html
systemd 256.7