Attaching file descriptors to processes with CLONE_FD

> Evolving? PIDs were always inconsistent in the sense that most resources on Unix were managed as file descriptors.
Well, "everything is a file" resources certainly are, but e.g. mutexes, timers, threads, processes, etc. are not (see win32). Oh wait, there's timerfd now... so yeah, I'd said it's been changing.

> Because presumably you'll be able to do that with this, which open ups all manner of possibilities for process management which don't involve cgroups or a global process manager.
I agree; this makes much of cgroups redundant. Obviously all of the current cgroups functionality needs to be adapted. I just wish the decision to go with process handles was made _before_ the design of cgroups.