Right now we allow scheduling of up to 2x CPUs on a given cloudvirt in the nova config. Some questions are:

• Is this number with or without hyperthreading? (I'm pretty sure it is 'with' which would mean we are physically scheduling 4x rather than 2x)
• What is actual CPU usage on the cloudvirts? Is it so low that we can increase our overscheduling ratio?
• Noisy neighbors:
  • Do cloudvirts /ever/ hit 100% usage such that noisy neighbors are an issue?
  • Are there edge cases where a cloudvirt has idle CPUs but there are virtual CPUs still contending for a single physical over-taxed CPU? Or is kvm smart in some way so that that never happens?
  • Do we have workloads that care so much about noisy neighbors that we need to provide special paths for select projects or VMs?