Re: RFC: Getting rid of LTR in VMX

[hpa]

On February 20, 2017 2:02:53 PM PST, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
>> > Yes.  But 150-200 clock cycles are nothing compared to the cache
>misses
>> > you get from preemption, so I'd ignore that.  Saving 300 clock
>cycles on
>> > userspace exits from TR+GSBASE would be about 5% on my Haswell.
>> 
>> That's still 5% :)
>
>Yes, 5% on userspace exits is good (though they're rare).
>
>OTOH, 300 clock cycles on preemption are nothing to write home about.
>
>Paolo

Oh, I would say it is... especially when it's basically free.
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