Trap 12 in vm_page_alloc_after()

[Garrett Wollman]

<<On Wed, 28 Nov 2018 19:19:04 -0500, Mark Johnston <markj at freebsd.org> said:

> If you're using a Skylake, I suspect that you can set the
> hw.skz63_enable tunable to 0 as a workaround, assuming you're not using
> any code that relies on Intel TSX.  (I don't think there's anything in
> the base system that does.)  There are some details in
> https://reviews.freebsd.org/D18374

It is definitely a Skylake (although it took searching to find that
out, since we don't identify processors by Intel codename).  I've
set that tunable, but I won't know whether it helps until the next
(scheduled or unscheduled) reboot.

-GAWollman