Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: Re: [OMPI users] Issue with Profiling Fortran code
From: Anthony Chan (chan_at_[hidden])
Date: 2008-12-05 03:16:36


Hope I didn't misunderstand your question. If you implement
your profiling library in C where you do your real instrumentation,
you don't need to implement the fortran layer, you can simply link
with Fortran to C MPI wrapper library -lmpi_f77. i.e.

<OMPI>/bin/mpif77 -o foo foo.f -L<OMPI>/lib -lmpi_f77 -lYourProfClib

where libYourProfClib.a is your profiling tool written in C.
If you don't want to intercept the MPI call twice for fortran program,
you need to implment fortran layer. In that case, I would think you
can just call C version of PMPI_xxx directly from your fortran layer, e.g.

void mpi_comm_rank_(MPI_Comm *comm, int *rank, int *info) {
    printf("mpi_comm_rank call successfully intercepted\n");
    *info = PMPI_Comm_rank(comm,rank);
}

A.Chan

----- "Nick Wright" <nwright_at_[hidden]> wrote:

> Hi
>
> I am trying to use the PMPI interface with OPENMPI to profile a
> fortran
> program.
>
> I have tried with 1.28 and 1.3rc1 with --enable-mpi-profile switched
> on.
>
> The problem seems to be that if one eg. intercepts to call to
> mpi_comm_rank_ (the fortran hook) then calls pmpi_comm_rank_ this then
>
> calls MPI_Comm_rank (the C hook) not PMPI_Comm_rank as it should.
>
> So if one wants to create a library that can profile C and Fortran
> codes
> at the same time one ends up intercepting the mpi call twice. Which is
>
> not desirable and not what should happen (and indeed doesn't happen in
>
> other MPI implementations).
>
> A simple example to illustrate is below. If somebody knows of a fix to
>
> avoid this issue that would be great !
>
> Thanks
>
> Nick.
>
> pmpi_test.c: mpicc pmpi_test.c -c
>
> #include<stdio.h>
> #include "mpi.h"
> void mpi_comm_rank_(MPI_Comm *comm, int *rank, int *info) {
> printf("mpi_comm_rank call successfully intercepted\n");
> pmpi_comm_rank_(comm,rank,info);
> }
> int MPI_Comm_rank(MPI_Comm comm, int *rank) {
> printf("MPI_comm_rank call successfully intercepted\n");
> PMPI_Comm_rank(comm,rank);
> }
>
> hello_mpi.f: mpif77 hello_mpi.f pmpi_test.o
>
> program hello
> implicit none
> include 'mpif.h'
> integer ierr
> integer myid,nprocs
> character*24 fdate,host
> call MPI_Init( ierr )
> myid=0
> call mpi_comm_rank(MPI_COMM_WORLD, myid, ierr )
> call mpi_comm_size(MPI_COMM_WORLD , nprocs, ierr )
> call getenv('HOST',host)
> write (*,*) 'Hello World from proc',myid,' out of',nprocs,host
> call mpi_finalize(ierr)
> end
>
>
>
> _______________________________________________
> users mailing list
> users_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/users