All:
The fix in this patch appears to be unconditional.
I do a lot of work with embedded Intel Atom processors, which do
not implement speculative execution. (Only one of them even
implements limited out-of-order execution.) These systems aren't
terribly powerful by today's standards, and would suffer serious
performance impacts should the fix be turned on unnecessarily. Will
there be automatic detection of 32-bit Atoms (all of which are
definitely not susceptible) and 64-bit Atoms (all of which, except
for Avoton, are definitely not susceptible; Avoton might have some
very limited exposure due to out-of-order execution, but may also
not be vulnerable because the OOE is not speculative) to avoid
unnecessary performance impacts?
--Brett Glass
At 05:14 AM 1/12/2018, Oliver Pinter wrote:
>The test patch is here: https://reviews.freebsd.org/D13797