System churning through cpu, checking journalctl -f:

Sep 12 16:10:56 koparo systemd[1]: Looping too fast. Throttling execution a little.

Googling the log msg (http://lists.freedesktop.org/archives/systemd-devel/2014-March/017835.html):

if (!ratelimit_test(&rl)) {
  /* Yay, something is going seriously wrong, pause a little */   
 log_warning("Looping too fast. Throttling execution a little.");

Yeah thanks +systemd really informative.