Belatedly document the disabling of Hyper-Threading.  Security issues
are not normally documented in UPDATING on the stable branches, but
since this is a user-visible change, it needs to be here.

This is not an MFC since Hyper-Threading is enabled by default in HEAD.

Pointed out by: Erik Trulsson, via freebsd-stable

Revision    Changes    Path
1.342.2.30  +5 -0      src/UPDATING