how XEN chontrol cores and whether there is a API in Linux to run process on designated core

Question

how XEN chontrol cores and whether there is a API in Linux to run process on designated core

Answer 1

AFAIK this is done using libvirt driver. You can specify the cpuset in nova configuration file and when the instance is being spawned, the libvirt driver checks the config file and the specified value is put in the instance's xml. The only shortcoming is that the given cpuset works for all the instances being spawned on that host. There is no way to specify different cpu cores for different instances. And yeah, there is no API to do this. Admin has to specify it explicitly in the config file. HTH.