I am going to reboot a bunch of machines tonight sometime midnight or after to change some configuration options. It turns out that there is a bug in virt-manager where if you tell it to copy the host CPU configuration, it doesn’t, instead it takes an four core, eight thread, CPU, and turns it into eight 1 thread CPU’s in the guest OS. This has less than optimal scheduling results in the guest kernel.
I can, however, manually set the architecture correctly, and this is what I’ll be doing, but it does require a guest shut-down and reboot to be effective.