Messages in this thread | | | Date | Fri, 23 Apr 2010 14:35:59 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH 1/5] Add a global synchronization point for pvclock |
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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 ;)
J
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