WNOHANG          1715 kernel/exit.c  	if (!retval && !(options & WNOHANG)) {
WNOHANG          1760 kernel/exit.c  	if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED))
WNOHANG          1800 kernel/exit.c  	if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|