NetBSD 7.0/xen scheduling mystery, and how to fix it with processor sets Today I had a need to do some number crunching using a home-brewn C program. In order to do some manual load balancing, I was firing up some Amazon AWS instances (which is Xen) with NetBSD 7.0. In this case, the system was assigned two CPUs, from dmesg: # dmesg | grep cpu vcpu0 at hypervisor0: Intel(R) Xeon(R) CPU E5-2680 v2