CPU isolation for host processes

[Karthik S]

The cores for host processes needs to be reserved, so that the remaining cores (isolated cores) are not used by the general kernel balancing, interrupt handling and scheduling algorithms. The isolated cores shall be used for guest VMs.

The default case shall use core “ZERO” and its sibling hyperthread (if hyper-threading is activated).

For example, if core “ZERO” needs to be reserved for host processes on a node with 8 cores, without hyperthreading, then the boot parameters shall have “ isolcpus=1-7 nohz_full=1-7 rcu_nocs=1-7”.

The number of CPU's to be reserved shall be taken from T-H-T

[Brent Eagles (beagles)]

This is related to the specs:

https://review.openstack.org/#/c/313871/
https://review.openstack.org/#/c/313872/

correct?

[Karthik S (ksundara)]

Yes Brent.

[Karthik S (ksundara)]

Its handled in Ocata using Tuned package and the corresponding cores are provided by THT.