Re: [PATCH v5 2/2] x86, mwaitt: introduce mwaix delay with a configurable timer

[Huang Rui]

On Mon, Jun 15, 2015 at 01:15:26PM +0200, Borislav Petkov wrote:
> On Mon, Jun 15, 2015 at 12:57:18PM +0200, Peter Zijlstra wrote:
> > Seeing how we disable C states, its unlikely to use less energy, so what
> > exactly is its benefit, other than using fancy new instructions?
> 
> If the "disabling of C states" turns into a "go into a C-state which has
> small wakeup latency" in the future, would be cool. Because we have a
> bunch of places where we do delay.
> 
> Rui, what happens if you enter C1 instead? Any improvements or is the
> wakeup latency too high?
> 

Hmm, the current processor cannot enter C1 with MWAITX, so I don't
confirm if it would have higher wakeup latency on C1 in future.

Thanks,
Rui
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