Comment 23 for bug 1202965

One more example: let's use hw:cpu_policy='dedicated'/hw:cpu_thread_policy='isolate' extra specs and launch as many instances as possible in 3 hosts (8 vcpus each, HT enabled). Finally "openstack hypervisor stats show" displays:

+----------------------+-------+
| Field | Value |
+----------------------+-------+
| count | 3 |
...
| running_vms | 6 |
| vcpus | 24 |
| vcpus_used | 12 |
+----------------------+-------+

At this point no more instances can be launched with the same flavor (at least in my case) because NUMATopologyFilter doesn't give any suitable hosts. This is OK but vcpus/vcpus_used values are quite confusing because they give an impression that only 50% of CPU resources are used.