You can print lscpu from the compute node, you will see below output as below:

[root@compute ~]# lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                40
On-line CPU(s) list:   0-39
Thread(s) per core:    2
Core(s) per socket:    10
Socket(s):             2
NUMA node(s):          2
Vendor ID:             GenuineIntel

So CPU(s): is the vCPUs in Openstack.

Formula for calculation is as follows:

vCPUs=`Thread(s) per core * Core(s) per socket * Socket(s)

ie. vCPUs=2*10*2

However overcommited vCPU will be calculated as following:

 "OverCommited vCPU" = vCPU*OverCommitmentRatio

ie "OverCommited vCPU" = 40*16= 640

thanks ..http://docs.openstack.org/trunk/openstack-compute/admin/content/corefilter.html is not working

BTW here is a handy calculator for that https://www.mirantis.com/openstack-se...