Dear member of the RMA group and especially the mpich developers, I have real problems with the new shared memory in MPI-3.0, i.e., the load/stores together with the RMA synchronization causes wrong execution results. The attached 1sided_halo_C_mpich_problems_rabenseifner.tar.gz or .zip contains - 1sided/halo_1sided_put_win_alloc.c The basis that works. It uses MPI_Put and MPI_Win_fence for duplex left/right halo communication. - 1sided/halo_1sided_store_win_alloc_shared.c This is the same, but a shared memory window is used and the MPU_Put is substituted by storing the data in the neighbors window. Same MPI_Win_fence with same assertions. This does not work, although I'm sure that my assertions are correct. Known possibilities: - I'm wrong and was not able to understand the assertions on MPI-3.0 p452:8-19. - I'm wrong because it is invalid to use the MPI_Win_fence together with the shared memory windows. - mpich has a bug. (The first two possibilities are the reason, why I use this Forum email list) - 1sided/halo_1sided_store_win_alloc_shared_w-a-cray.c This is a work-around-for Cray that works on our Cray and does not use MPI_MODE_NOPRECEDE and MPI_MODE_NOSUCCEED. It also runs on another mpich installation. - 1sided/halo_1sided_store_win_alloc_shared_pscw.c Here, MPI_Win_fence is substituted by Post-Start-Complete-Wait and it does not work for any assertions. Same possibilities as above. - 1sided/halo_1sided_store_win_alloc_shared_query.c - 1sided/halo_1sided_store_win_alloc_shared_query_w-a-cray.c Same as halo_1sided_store_win_alloc_shared.c but non-contigues windows are used. Same problems as above. - 1sided/halo_1sided_store_win_alloc_shared_othersync.c This version uses the synchronization according to #413 and it is tested and works on two platforms. Best regards Rolf -- Dr. Rolf Rabenseifner . . . . . . . . . .. email [email protected] High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307)