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

[H. Peter Anvin]

Jeremy Fitzhardinge wrote:
> Ingo Molnar wrote:
>> ( another advantage is that the 6 bytes GDT descriptor is more  
>> compressed and hence uses up less L1/L2 cache footprint than the  
>> larger (~7 byte) trampolines we have at the moment. )
>>   
> 
> Also its D cache rather than I cache, which is generally more
> plentiful.  However, I think the cost of GDT cache misses on exception
> latency is something that we've largely overlooked, and this will make
> it a bigger factor (vs cache misses on the actual exception handler code
> itself, which should be reduced).
> 

Besides, a GDT entry is 8 bytes, not 6.

	-hpa