sudo systemctl status gdm
[sudo] password for william:
● gdm.service - GNOME Display Manager
   Loaded: loaded (/lib/systemd/system/gdm.service; static; vendor preset: enabled)
   Active: active (running) since Sun 2018-06-17 21:09:52 EDT; 44min ago
  Process: 3141 ExecReload=/bin/kill -SIGHUP $MAINPID (code=exited, status=0/SUCCESS)
  Process: 3138 ExecReload=/usr/share/gdm/generate-config (code=exited, status=0/SUCCESS)
 Main PID: 1319 (gdm3)
    Tasks: 3 (limit: 4915)
   CGroup: /system.slice/gdm.service
           └─1319 /usr/sbin/gdm3

Jun 17 21:09:52 little-black-box systemd[1]: Started GNOME Display Manager.
Jun 17 21:09:52 little-black-box gdm-launch-environment][1334]: pam_unix(gdm-launch-environment:session): session opened for user gdm by (uid=0)
Jun 17 21:09:53 little-black-box gdm-launch-environment][1334]: pam_unix(gdm-launch-environment:session): session closed for user gdm
Jun 17 21:09:53 little-black-box gdm3[1319]: GdmDisplay: display lasted 0.507979 seconds
Jun 17 21:09:53 little-black-box gdm3[1319]: Child process -1355 was already dead.
Jun 17 21:09:53 little-black-box gdm3[1319]: Child process 1334 was already dead.
Jun 17 21:09:53 little-black-box gdm3[1319]: Unable to kill session worker process
Jun 17 21:09:53 little-black-box gdm-launch-environment][1417]: pam_unix(gdm-launch-environment:session): session opened for user gdm by (uid=0)
Jun 17 21:12:52 little-black-box systemd[1]: Reloading GNOME Display Manager.
Jun 17 21:12:52 little-black-box systemd[1]: Reloaded GNOME Display Manager.