Was this "Fix" ever merged for production release?  I"m running Openstack-Ansible Pike (16.0.1) and I'm still getting this error.  Based on your number / release cycle, this error has probably been floating around for 2 years.  Embarrassing.

2017-11-06 15:33:54.427 6079 DEBUG neutron.agent.linux.utils [-] Running command: ['sudo', '/openstack/venvs/neutron-16.0.1/bin/neutron-rootwrap', '/etc/neutron/rootwrap.conf', 'kill', '-9', '6080'] create_process /openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/neutron/agent/linux/utils.py:92
2017-11-06 15:33:54.437 6079 CRITICAL neutron [-] Unhandled error: AssertionError: do not call blocking functions from the mainloop
2017-11-06 15:33:54.437 6079 ERROR neutron Traceback (most recent call last):
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/bin/neutron-keepalived-state-change", line 11, in <module>
2017-11-06 15:33:54.437 6079 ERROR neutron     sys.exit(main())
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/neutron/cmd/keepalived_state_change.py", line 19, in main
2017-11-06 15:33:54.437 6079 ERROR neutron     keepalived_state_change.main()
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/neutron/agent/l3/keepalived_state_change.py", line 156, in main
2017-11-06 15:33:54.437 6079 ERROR neutron     cfg.CONF.monitor_cidr).start()
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/neutron/agent/linux/daemon.py", line 253, in start
2017-11-06 15:33:54.437 6079 ERROR neutron     self.run()
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/neutron/agent/l3/keepalived_state_change.py", line 69, in run
2017-11-06 15:33:54.437 6079 ERROR neutron     for iterable in self.monitor:
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/neutron/agent/linux/async_process.py", line 261, in _iter_queue
2017-11-06 15:33:54.437 6079 ERROR neutron     yield queue.get(block=block)
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/eventlet/queue.py", line 313, in get
2017-11-06 15:33:54.437 6079 ERROR neutron     return waiter.wait()
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/eventlet/queue.py", line 141, in wait
2017-11-06 15:33:54.437 6079 ERROR neutron     return get_hub().switch()
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/eventlet/hubs/hub.py", line 294, in switch
2017-11-06 15:33:54.437 6079 ERROR neutron     return self.greenlet.switch()
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/eventlet/hubs/hub.py", line 346, in run
2017-11-06 15:33:54.437 6079 ERROR neutron     self.wait(sleep_time)
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/eventlet/hubs/poll.py", line 85, in wait
2017-11-06 15:33:54.437 6079 ERROR neutron     presult = self.do_poll(seconds)
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/eventlet/hubs/epolls.py", line 62, in do_poll
2017-11-06 15:33:54.437 6079 ERROR neutron     return self.poll.poll(seconds)
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/neutron/agent/l3/keepalived_state_change.py", line 133, in handle_sigterm
2017-11-06 15:33:54.437 6079 ERROR neutron     self._kill_monitor()
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/neutron/agent/l3/keepalived_state_change.py", line 130, in _kill_monitor
2017-11-06 15:33:54.437 6079 ERROR neutron     run_as_root=True)
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/neutron/agent/linux/utils.py", line 223, in kill_process
2017-11-06 15:33:54.437 6079 ERROR neutron     execute(['kill', '-%d' % signal, pid], run_as_root=run_as_root)
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/neutron/agent/linux/utils.py", line 131, in execute
2017-11-06 15:33:54.437 6079 ERROR neutron     _stdout, _stderr = obj.communicate(_process_input)
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/usr/lib/python2.7/subprocess.py", line 800, in communicate
2017-11-06 15:33:54.437 6079 ERROR neutron     return self._communicate(input)
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/usr/lib/python2.7/subprocess.py", line 1419, in _communicate
2017-11-06 15:33:54.437 6079 ERROR neutron     stdout, stderr = self._communicate_with_select(input)
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/usr/lib/python2.7/subprocess.py", line 1520, in _communicate_with_select
2017-11-06 15:33:54.437 6079 ERROR neutron     rlist, wlist, xlist = select.select(read_set, write_set, [])
2017-11-06 15:33:54.437 6079 ERROR neutron   File "/openstack/venvs/neutron-16.0.1/lib/python2.7/site-packages/eventlet/green/select.py", line 40, in select
2017-11-06 15:33:54.437 6079 ERROR neutron     assert hub.greenlet is not current, 'do not call blocking functions from the mainloop'
2017-11-06 15:33:54.437 6079 ERROR neutron AssertionError: do not call blocking functions from the mainloop
2017-11-06 15:33:54.437 6079 ERROR neutron

Is there any fix?