Hello,
When I run this code:
program testcase
use mpi
implicit none
integer :: rank, lsize, rsize, code
integer :: intercomm
call MPI_INIT(code)
call MPI_COMM_GET_PARENT(intercomm, code)
if (intercomm == MPI_COMM_NULL) then
call MPI_COMM_SPAWN ("./testcase", MPI_ARGV_NULL, 1, MPI_INFO_NULL,
&
0, MPI_COMM_WORLD, intercomm, MPI_ERRCODES_IGNORE, code)
call MPI_COMM_RANK(MPI_COMM_WORLD, rank, code)
call MPI_COMM_SIZE(MPI_COMM_WORLD, lsize, code)
call MPI_COMM_SIZE(intercomm, rsize, code)
if (rank == 0) then
print *, 'from parent: local size is ', lsize
print *, 'from parent: remote size is ', rsize
end if
else
call MPI_COMM_SIZE(MPI_COMM_WORLD, lsize, code)
call MPI_COMM_SIZE(intercomm, rsize, code)
print *, 'from child: local size is ', lsize
print *, 'from child: remote size is ', rsize
end if
call MPI_FINALIZE (code)
end program testcase
I get the following results with openmpi 1.4.1 and two processes:
from parent: local size is
2
from parent: remote size is
2
from child: local size is
1
from child: remote size is
1
I would have expected:
from parent: local size is
2
from parent: remote size is 1
from child: local size is
1
from child: remote size is 2
Could anyone tell me what's going on ? It's not a fortran issue, I can also
replicate it using mpi4py.
Probably related to the universe size: I haven't found a way to hand it to
mpirun.
Cheers,
Pierre
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