I'am developing mpi4py, a MPI port for Python. I've wrote many unittest scripts for my wrappers, which also pretend to test MPI implementations.
Below, I list some issues I've found when building my wrappers with Open MPI 1.1.1. Please let me know your opinions. - MPI_Group_translate_ranks(group1, n, ranks1, group2, ranks2) fails (with MPI_ERR_GROUP) if n != size(group1). Regarding the standard, I understand this routine should whork for any value of n, if ranks1 contains values (even if some are duplicated) in a valid range according to size(group1). - MPI_Info_get_nthkey(INFO, 0, key) does not fail when INFO is empty, ie, when MPI_Info_get_nkeys(info, &nkeys) returns nkeys==0. - Usage of MPI_IN_PLACE is broken in some collectives, below the reasons I've found: + MPI_Gather: with sendbuf=MPI_IN_PLACE, sendcount is not ignored. + MPI_Scatter: with recvbuf=MPI_IN_PLACE, recvcount is not ignored. + MPI_Allgather: with sendbuf=MPI_IN_PLACE, sendcount is not ignored. The standard says that [send|recv]count and [send|recv]type are ignored. I've not tested vector variants, perhaps they suffer the same problem. - Some extended collective communications failed (not by raising errors, but instead aborting tracing to stdout) when using intercommunicators. Sometimes, the problems appeared when size(local_group) != size(remote_group). However, MPI_Barrier and MPI_Bcast worked well. I still could not get the reasons for those failures. I've found a similar problem in MPICH2 when configured with error-cheking enabled (they had a bug in some error-cheking macros, I reported this issue and next they told me I was right). -- Lisandro Dalcín --------------- Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC) Instituto de Desarrollo Tecnológico para la Industria Química (INTEC) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) PTLC - Güemes 3450, (3000) Santa Fe, Argentina Tel/Fax: +54-(0)342-451.1594
