gdm.service - GNOME Display Manager
   Loaded: loaded (/lib/systemd/system/gdm.service; static; vendor preset: enabled)
  Drop-In: /lib/systemd/system/display-manager.service.d
           └─xdiagnose.conf
   Active: active (running) since Wed 2016-08-03 08:02:13 CDT; 6h ago
  Process: 3045 ExecStartPre=/usr/share/gdm/generate-config (code=exited, status=0/SUCCESS)
  Process: 3031 ExecStartPre=/bin/sh -c [ "$(cat /etc/X11/default-display-manager 2>/dev/null)" = "/usr/sbin/gdm3" ] (code=exited, status=0/SUCCESS)
 Main PID: 3050 (gdm3)
   CGroup: /system.slice/gdm.service
           └─3050 /usr/sbin/gdm3

Aug 03 08:02:12 localhost systemd[1]: Starting GNOME Display Manager...
Aug 03 08:02:13 localhost systemd[1]: Started GNOME Display Manager.
Aug 03 08:02:17 localhost gdm-launch-environment][3102]: pam_unix(gdm-launch-environment:session): session opened for user gdm by (uid=0)