Symbol: sys_umtx_sleep
sys/kern/init_sysent.c
486
{ AS(umtx_sleep_args), 4, (sy_call_t *)sys_umtx_sleep }, /* 469 = umtx_sleep */
sys/sys/sysproto.h
1704
int sys_umtx_sleep (struct sysmsg *sysmsg, const struct umtx_sleep_args *);