Alternate title: Red Hat speeds up Red Hat Linux with 4 lines of code and systemd.
I was wondering when the freedesktop dudes were going to make a "come back". Linus, in fact, does not oppose the user level approach [1]. I too, however, share his disgust for user level code to interact with every process and group, it's just awful. The kernel seems like a good place to implement an interface for this, that user space can use effectively and without imposing extra complexity on the kernel.