Isolate CPU for kvm

[jpp_]

Hello.
I move from systemd to openrc again

And i wish to have a hook qemu working

cat /etc/libvirt/hooks/qemu

[user]

Hi jpp_
qemu don't support native cpu pinning after years and cgroups setup maybe too hassle so playing with taskset can be useful.
Something like:

[szatox]

Haven't tried it, but I think it could be done with cgroups.
Like in, drop the process and cpu cores it's supposed to run on into the same cgroup. If I understand it correctly, the process and all its children spawned afterwards will be pinned to those selected cores and also those cores will be reserved for said processes.
Looks promising.

Taskset is a bit simpler, it can prevent a process from running on some cores, but it's very easy to use, so yeah, it is a good first pick.

I wonder what you're trying to achieve though, why is default scheduling not good enough? Are your processes constantly getting kicked around causing cache misses or something like that?

[jpp_]

For what i read, im trying to use one physical part of the cpu with his cache only for the vm, so the host dont see / use it and add latency, and also i use part of the other half to iothread and qemu.

Part of the VM xml