dockerd: remove default -500 oom-score-adjust

dockerd currently sets the oom-score-adjust itself. This functionality
was added when we did not yet run dockerd as a systemd service.

Now that we do, it's better to instead have systemd handle this.

Keeping the option itself for situations where dockerd is started
manually or without using systemd.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cmd/dockerd/config_unix.go

@@ -52,7 +52,7 @@ func installConfigFlags(conf *config.Config, flags *pflag.FlagSet) error {
 	flags.StringVar(&conf.CgroupParent, "cgroup-parent", "", "Set parent cgroup for all containers")
 	flags.StringVar(&conf.RemappedRoot, "userns-remap", "", "User/Group setting for user namespaces")
 	flags.BoolVar(&conf.LiveRestoreEnabled, "live-restore", false, "Enable live restore of docker when containers are still running")
-	flags.IntVar(&conf.OOMScoreAdjust, "oom-score-adjust", -500, "Set the oom_score_adj for the daemon")
+	flags.IntVar(&conf.OOMScoreAdjust, "oom-score-adjust", 0, "Set the oom_score_adj for the daemon")
 	flags.BoolVar(&conf.Init, "init", false, "Run an init in the container to forward signals and reap processes")
 	flags.StringVar(&conf.InitPath, "init-path", "", "Path to the docker-init binary")
 	flags.Int64Var(&conf.CPURealtimePeriod, "cpu-rt-period", 0, "Limit the CPU real-time period in microseconds for the parent cgroup for all containers")