I have KillUserProcesses=yes set in Fedora 24 for some time now. I'm
noticing that I still often have 90 second delays if I restart or
shutdown, more than half the time. If I log out, I always get fast log
outs, and more often than not a restart/shutdown from the login window
is also fast. So there's something different about directly choosing
restart/shutdown inside the user login session, versus logging out
first then restarting/shutting down. I have no idea how to collect
more information on why I'm experiencing this.