Re: Sysenter crash with Nested Task Bit set

[Jeremy Fitzhardinge]

Andi Kleen wrote:
> Yes it's never fast, but on basically all non P4 CPUs it is still fast enough
> to not be a problem. I suppose it causes a trace cache flush or something like
> that there.

I don't think it's that bad, but it might cause a full pipeline flush.  
I seem to remember measuring its cost at about 50 cycles.

   J

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