This breaks the kernel boot in EC2 Xen-based instances; it now hangs
in the taskqgroup_adjust_if_io_tqg SYSINIT. I've attached a verbose
dmesg from r335666 in case that helps you figure out what's going on.
My guess is that EC2 is numbering virtual CPUs oddly -- but regardless
of the cause, this
Author: royger
Date: Tue Jun 26 15:00:54 2018
New Revision: 335668
URL: https://svnweb.freebsd.org/changeset/base/335668
Log:
xen: obtain vCPU ID from CPUID
The Xen vCPU ID can be fetched from the cpuid instead of inferring it
from the ACPI ID.
Sponsored by: Citrix Systems R
