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

From: H. Peter Anvin
Date: Tue Nov 04 2008 - 19:55:27 EST


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
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