[Lguest] [PATCH RFC/RFB] x86_64, i386: interrupt dispatch changes

[Ingo Molnar]

* Cyrill Gorcunov <gorcunov at gmail.com> wrote:

> [Alexander van Heukelum - Tue, Nov 04, 2008 at 05:23:09PM +0100]
> ...
> | 
> | I did some timings using the little program below (32-bit only), doing
> | 1024 times the same sequence. TEST1 is just pushing a constant onto
> | the stack; TEST2 is pushing the cs register; TEST3 is the sequence
> | from the patch to extract the vector number from the cs register.
> | 
> | Opteron    (cycles): 1024 / 1157 / 3527
> | Xeon E5345 (cycles): 1092 / 1085 / 6622
> | Athlon XP  (cycles): 1028 / 1166 / 5192
> 
> Xeon is defenitely out of luck :-)

it's still OK - i.e. no outrageous showstopper overhead anywhere in 
that instruction sequence. The total round-trip overhead is what will 
matter most.

	Ingo