vge_watchdog
callout_init_mtx(&sc->vge_watchdog, &sc->vge_mtx, 0);
callout_drain(&sc->vge_watchdog);
static void vge_watchdog(void *);
callout_reset(&sc->vge_watchdog, hz, vge_watchdog, sc);
callout_reset(&sc->vge_watchdog, hz, vge_watchdog, sc);
callout_stop(&sc->vge_watchdog);
struct callout vge_watchdog;