https://bugzilla.redhat.com/show_bug.cgi?id=1069718
--- Comment #3 from Lennart Poettering lpoetter@redhat.com --- The O(n^2) PropertiesChanged messages will not be generated anymore with systemd git:
http://cgit.freedesktop.org/systemd/systemd/commit/?id=ff5f34d08c191c326c41a...
But I am working on a couple of more fixes to follow.
And again, the kernel interface of /proc/self/mountinfo forces us to do some time O(n^2) things here, so we cannot really fix this without kernel support to scale better than that: when you mount a thousand mounts, then this will in the worst case generate a thousand POLLURG events to systemd, which will then read in the worst case a thousand entries from /proc/self/mountinfo, each time. The kernel interface would need have to tell us about invidiual mounts coming/going if we want this to scale better than O(n^2) in the long run...