OOMPolicy=
     Configure the out-of-memory (OOM) killing policy for the kernel and the
     userspace OOM killer systemd‐oomd.service(8). On Linux, when memory becomes
     scarce to the point that the kernel has trouble allocating memory for
     itself, it might decide to kill a running process in order to free up memory
     and reduce memory pressure. Note that systemd-oomd.service is a more
     flexible solution that aims to prevent out-of-memory situations for the
     userspace too, not just the kernel, by attempting to terminate services
     earlier, before the kernel would have to act.

     This setting takes one of continue, stop or kill. If set to continue and a
     process in the unit is killed by the OOM killer, this is logged but the unit
     continues running. If set to stop the event is logged but the unit is
     terminated cleanly by the service manager. If set to kill and one of the
     unit's processes is killed by the OOM killer the kernel is instructed to
     kill all remaining processes of the unit too, by setting the
     memory.oom.group attribute to 1; also see kernel documentation[2].

     Defaults to the setting DefaultOOMPolicy= in systemd‐system.conf(5) is set
     to, except for units where Delegate= is turned on, where it defaults to
     continue.

     Use the OOMScoreAdjust= setting to configure whether processes of the unit
     shall be considered preferred or less preferred candidates for process
     termination by the Linux OOM killer logic. See systemd.exec(5) for details.

     This setting also applies to systemd‐oomd.service(8). Similarly to the
     kernel OOM kills performed by the kernel, this setting determines the state
     of the unit after systemd-oomd kills a cgroup associated with it.