On Tue, Mar 15, 2011 at 09:48:40PM -0500, Rajeev Thakur wrote:

Also, at the last meeting we had trouble defining the MPI_SHM_Fence function. Dave said we won't be able to define it portably for all processor architectures wrt memory orderings etc. Someone else pointed out that, in Fortran, code can be moved around it. Those issues won't go away by effectively renaming MPI_SHM_Fence to MPI_Win_flush. (These issues are wrt direct loads/stores to shared memory.) I know, those issues are the same for a fast implementation on a shared memory system (one that doesn't do a membar in every put/get/...). So I think this issue is orthogonal and independent of the interface.

Best, Torsten -- bash$ :(){ :|:&};: --------------------- http://www.unixer.de/ ----- Torsten Hoefler | Performance Modeling and Simulation Lead Blue Waters Directorate | University of Illinois (UIUC) 1205 W Clark Street | Urbana, IL, 61801 NCSA Building | +01 (217) 244-7736