Re: [PATCH 1/5] Add a global synchronization point for pvclock

Zachary Amsden
2010-04-23T21:41:18Z

On 04/23/2010 11:35 AM, Jeremy Fitzhardinge wrote:
> On 04/23/2010 02:31 PM, Zachary Amsden wrote:
>
>> Does lfence / mfence actually serialize? I thought there was some
>> great confusion about that not being the case on all AMD processors,
>> and possibly not at all on Intel.
>>
>> A trap, however is a great way to serialize.
>>
>> I think, there is no serializing instruction which can be used from
>> userspace which does not trap, at least, I don't know one off the top
>> of my head.
>>
> rsm is not technically privileged... but not quite usable from usermode ;)
>

rsm under hardware virtualization makes my head hurt