RFC: Simplfying hyperthreading distinctions

[Adrian Chadd]

Hi!

1) I'd rather we leave them as SMT/HTT as they're slightly different
things. Who knows if intel will re-introduce this stuff in their more
embedded CPU line at a future time, or add another threading type in
the future. Being told about the distinction is nice.
2) I'd rather we had it more clearly defind - machdep.htt_allowed /
machdep.smt_allowed . Again, I'd rather have the distinction in case
Intel decide again to make their embedded things use old-style
threading. (The intel edison/galilleo boards use P1 style cores that
are low power, I can imagine a world where they reuse HTT for that.)
3) I'd like that kind of tunable setting.

And:

4) Yes, I'd also like a machdep tunable for "don't bother routing
interrupts to SMT / HTTs". You have that patch in your jhbbsd tree; I
don't think it's in HEAD yet?



-adrian