does s6-supervise listen to the given "readiness notification" fd ? seems so to me.
Yes, it does.
that is the reason s6 style "readiness notification" would be hard to do directly with perpd since it is a more integrated solution that does not use intermediary supervise processes.
It would certainly be possible for perpd to do the same, as long as it stays under the max open file limit - which may reduce the maximum possible number of services, but not enough for it to be a serious limitation. -- Laurent
