pay-service on idle machine is polling at ~1Hz causing system wakeups

[Colin Ian King]

Looking at the wakeups stats recently on mako, I spotted that the new pay-service is one of the top wakeup contributors to an idle system, cf:

http://ci.ubuntu.com/power/eventstat/image/3435/machine/6/task_type/all/details/

I ran health-check against this (see the attached log) using "health-check -c -f -r -d 300 -p $(pidof pay-service)" and can observe that there are two threads that are doing polls at ~0.5Hz each, contributing to a 1Hz wakeup rate.

Strace shows the polls to be in the form of:

strace shows that the poll wakeups do come from wakeups from active fd's so it may be all legitimate activity. But it does seem rather busy a idle service to me.

[dobey (dobey)]

Taking this and setting to in progress, as the new pay-service rewrite in go will fix this, as it's dbus activated and has a timeout to exit after a period of inactivity.