Re: [PATCH v7 8/8] x86/tlb: just do tlb flush on one of siblingsof SMT

[Peter Zijlstra]

On Thu, 2012-05-24 at 06:19 -0700, Andrew Lutomirski wrote:
> 
> A decent heuristic might be to prefer idle SMT siblings for TLB
> invalidation.  I don't know what effect that would have on power
> consumption (it would be rather bad if idling one SMT thread while the
> other one is busy saves much power). 

Right, I've never really understood how C-states and SMT go together.
Arjan recently implied waking a thread sibling from C-state was
'expensive' which on first thought seems daft, the core is running
already.



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