[Speed] Ubuntu 16.04 speed issues

[Paul Graydon]

I've a niggling feeling there was discussion about some performance drops on 16.04 not all that long ago, but I'm
completely failing to find it in my emails.

The OpenStack-Ansible project has noticed that performance on Ubuntu 16.04 is quite significantly slower than on 14.04.
At the moment it's looking like *possibly* a GCC related bug.

https://bugs.launchpad.net/ubuntu/+source/python2.7/+bug/1638695