[mpiwg-rma] FW: [Mpi3-rma] [EXTERNAL] Re: MPI-3 UNIFIED model updates

Pavan Balaji balaji at mcs.anl.gov
Tue Aug 27 14:59:10 CDT 2013


Hi Brian,

On 08/27/2013 01:49 PM, Barrett, Brian W wrote:
> I'm having trouble with the exact phrasing, but my thought is that we
> should have an advice to users that says 1) while the view of memory is
> consistent in UNIFIED, other artifacts (such as processor or memory
> controller reordering) can result in unexpected behavior 2) MPI_WIN_SYNC
> may be used to provide stronger ordering guarantees and 3) an application
> programmer may use other, implementation defined, semantics to provide
> required ordering guarantees.

Isn't (3) true for any MPI call in general, since the user can use 
implementation-defined alternate mechanisms for any of them?

Also, I think we are ignoring the point Jim raised: does OpenSHMEM 
really need these semantics?

  -- Pavan

-- 
Pavan Balaji
http://www.mcs.anl.gov/~balaji



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