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