b6ae696fc9
improve boot performance; this produces arguably astonishing (non-)results if /etc/rc.conf is modified during the boot process. Since performance considerations make it infeasible to automatically detect if the cached /etc/rc.conf parameters should be invalidated, provide a mechanism for explicitly requesting that /etc/rc.conf be reloaded: Catch SIGALRM and reload /etc/rc.conf if it is received. Discussed on: freebsd-rc MFC after: 3 days