On Mon, Feb 05, 2018 at 01:48:54PM +0100, Peter Zijlstra wrote: > So while I see the point of tracking these numbers (for SMT>2), I don't > think its worth doing outside of the core, and then we still need some > powerpc (or any other architecture with abysmal atomics) tested.
FWIW Power has another 'fun' feature, their cores have asymmetric SMT. Their cores have a static power level, based on _which_ SMT sibling is running, not how many. A single SMT2 runs (much) slower than a single SMT0. So that random selection stuff really doesn't work well for them. Now 'sadly' x86 can also have ASYM_PACKING set on its SMT domain, so I'm going to have to figure out what to do about all that.
