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

[H. Peter Anvin]

Jeremy Fitzhardinge wrote:
> Andi Kleen wrote:
>> ???  LOCK slowness is not because of the bus. And I know you know that
>> Ingo, so I don't know why you wrote that bogosity above.
>>   
> 
> Why are the accesses locked?  Is it because it does an update of the
> accessed bit in the descriptor?  (We should be pre-setting them all
> anyway.)
> 

It is, but the locked access is unconditional.  Similar to any other
read/modify/write transaction -- the write is required to release the lock.

	-hpa