openmpi does not produce working Fortran MPI2 program

[dstrubbe (David Strubbe)]

MPI2 support in the openmpi port does not seem to be working. I show below a simple test case using MPI_IN_PLACE for MPI_Allreduce, which fails for all numbers of processors I tried (1, 2, 3, 4; including running it without openmpiexec), and for various installations of openmpi which I tried ( 1.6.2_0+gcc45, 1.7.1_0+g95, and openmpi @1.7.1_0+gcc47). But it does work fine with mpich. I also obtained correct output for OpenMPI 1.4 on a Linux machine with Intel or GNU compilers.

Incorrect:

$ openmpif90 test.f90
$ openmpirun -n 3 ./a.out
 before, node            0 :           1
 before, node            1 :           1
 before, node            2 :           1
 after,  node            0 :           0
 after,  node            1 :           0
 after,  node            2 :           0

Correct, with mpich @3.0.4_0+gcc47:

$mpif90 test.f90
$ mpirun -n 3 ./a.out 
 before, node            0 :           1
 before, node            1 :           1
 before, node            2 :           1
 after,  node            0 :           3
 after,  node            1 :           3
 after,  node            2 :           3

program test

  use mpi

  integer :: mpierr
  integer, parameter :: SIZE = 1
  integer :: data(SIZE)

  call MPI_Init(mpierr)
  call MPI_Comm_rank(MPI_COMM_WORLD, inode, mpierr)

  data(1:SIZE) = 1

  write(6,*) 'before, node ', inode, ':', data

  call MPI_Allreduce(MPI_IN_PLACE, data, SIZE, MPI_INTEGER, MPI_SUM, MPI_COMM_WORLD, mpierr)

  write(6,*) 'after,  node ', inode, ':', data

  call MPI_Finalize(mpierr)

end program test

[petrrr]

Cc Me!

[dstrubbe (David Strubbe)]

This seems to be a MacOS-specific issue. I found a thread and ticket about it at ​http://www.open-mpi.org/community/lists/users/2011/11/17862.php and ​http://www.open-mpi.org/community/lists/users/2013/01/21077.php. The fix mentioned in the first (-Wl,-commons,use_dylibs) is present in the version of OpenMPI we are using, and is correctly added by the configure script on my machine. I tried manually adding the second fix ( -Wl,-flat_namespace) to my link-line with openmpif90 and it doesn't seem to make any difference unfortunately.

[seanfarley (Sean Farley)]

I just tested this and it seems work on my machine. Let me know if the issue still exists.

[dstrubbe (David Strubbe)]

I am reopening. It still doesn't work for me, on 3 different machines I tested:

• openmpi-default @1.7.4_0+gcc48 on OSX 10.8.5, XCode 5.1
• openmpi-default @1.7.4_0+gcc48 on OSX 10.9.2, XCode 5.1
• openmpi-default @1.7.4_0+gcc45 on OSX 10.6.8, XCode 3.2.6.

[seanfarley (Sean Farley)]

Ok, I'm able to reproduce this but have no idea why the linker flags don't work. I've updated openmpi to 1.7.5 and have put in -Wl,-flat_namespace to fix #42667 but things still don't work. At this point, we probably need a dev from OpenMPI to help us because I'm stuck.

[seanfarley (Sean Farley)]

Replying to sean@…:

Ok, I'm able to reproduce this but have no idea why the linker flags don't work. I've updated openmpi to 1.7.5 and have put in -Wl,-flat_namespace to fix #42667 but things still don't work. At this point, we probably need a dev from OpenMPI to help us because I'm stuck.

Actually, I was able to fix this by rebuilding OpenMPI. I'll push this soon.

[seanfarley (Sean Farley)]

Fixed in r118768. Thanks for the report!