Fair enough. But be aware that if you are building MPICH with double-width Fortran types and single-width C types, you might want to verify that MPICH is actually working properly.
Open MPI is refusing to configure because for each Fortran type X, it looks for a corresponding C type Y. If it can't find a correspondence, then it fails/aborts configure (i.e., it lets a human figure it out -- usually by ensuring that there are equivalent flags for the C/C++ and Fortran compilers). At least in Open MPI, having a C/Fortran type equivalence is necessary for reduction operations (because we do them in C). I don't know if MPICH has this restriction or not. In your case, Open MPI is failing to find a basic (single-width) C type that corresponds to the (double-width) Fortran type COMPLEX. This may not matter for your specific application, but we tend to take an all-or-nothing approach to configuration/building (i.e., we won't knowingly build a half-functional Open MPI). I hope that our rationale for this design choice at least makes sense. Also, if you are compiling your application with double-width Fortran types but are compiling your application with single-width Fortran types (this is how the thread started), that's quite dangerous -- your MPI doesn't agree with your application on the size of Fortran types, and all types of unpredictable hilarity can/will ensure. That's exactly why you were getting a 0 from MPI_WTIME() in Open MPI -- Open MPI was returning an 8 byte DOUBLE PRECISION, but your application was looking for a 16 byte DOUBLE PRECISION. I can't tell from your replies, but I'm guessing you compiled MPICH with double-width Fortran types and single-width C types. In this case, you should get correct values back from MPI_WTIME (because both MPI and your application use 16-byte DOUBLE PRECISIONS). What is an open question is how MPICH treats reductions on Fortran types (i.e., whether they are done in C or Fortran), and/or whether it matters for your application. > On Dec 20, 2016, at 5:51 AM, 🐋 Jan Hegewald <jan.hegew...@awi.de> wrote: > > Hi Gilles, > >> On 20 Dec 2016, at 05:31, Gilles Gouaillardet <gil...@rist.or.jp> wrote: >> > >> btw, do you really want 32 bytes complex in Fortran ? > > that is not for me to decide. I also do not want to change the default build > just because of the open-mpi flags. > >> >> if yes, then you should use an other compiler (such as gcc/g++) >> >> if not, then you can configure with FFLAGS='-fdefault-real-8 >> -fdefault-double-8', > > Thank you for the suggestion. open-mpi configures and compiles find now, but > running my program fails: > > An error occurred in MPI_Comm_size > reported by process [2925920257,6] > on communicator MPI_COMM_WORLD > MPI_ERR_COMM: invalid communicator > > I will continue to use mpich at this point, as I do not have the time for now > to fiddle with the open-mpi configuration. I like open-mpi better, so maybe I > will invest more time to get it running next year. > > Cheers and many thanks for all the suggestions, > Jan > _______________________________________________ > devel mailing list > devel@lists.open-mpi.org > https://rfd.newmexicoconsortium.org/mailman/listinfo/devel -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/ _______________________________________________ devel mailing list devel@lists.open-mpi.org https://rfd.newmexicoconsortium.org/mailman/listinfo/devel
