Hi,
I am using mpi_comm_spawn_multiple to spawn multiple commands with argument
lists. I am trying to do this in fortran (77) using version openmpi-1.4.1 and
the ifort compiler v9.0. The operating system is SuSE Linux 10.1 (x86-64).
I have put together a simple controlling example program (test_pbload.F) and an
example slave program (spray.F) to try and explain my problem.
In the controlling program mpi_comm_spawn_multiple is used to set 2 copies of
the slave running. The first is started with the argument list "1 2 3 4" and
the second with "5 6 7 8".
The slaves are started OK and the slaves print out the argument lists and exit.
In addition the slaves print out their rank numbers so I can see which argument
list belongs to which slave.
What I am finding is that the argument lists are not being sent to the slaves
correctly, indeed both slaves seem to be getting both arguments lists !!!
To compile and run the programs I follow the steps below.
Controlling program "test_pbload.F"
mpif77 -o test_pbload test_pbload.F
Slave program "spray.F"
mpif77 -o spray spray.F
Run the controller
mpirun -np 1 test_pbload
The output of which is from the first slave:
nsize, mytid: iargs 2 0 : 2
spray: 0 1:1 2 3 4 < FIRST ARGUMENT
spray: 0 2:4 5 6 7 < SECOND ARGUMENT
and the second slave:
nsize, mytid: iargs 2 1 : 2
spray: 1 1:1 2 3 4 < FIRST ARGUMENT
spray: 1 2:4 5 6 7 < SECOND ARGUMENT
In each case the arguments (2 in both cases) are the same.
I have written a C version of the controlling program and everthing works as
expected so I presume that I have either got the specification of the argument
list wrong or I have discovered an error/bug. At the moment I working on the
former -- but am at a loss to see what is wrong !!
Any help, pointers etc really appreciated.
Controlling program (that uses MPI_COMM_SPAWN_MULTIPLE) test_pbload.F
program main
c
implicit none
#include "mpif.h"
integer error
integer intercomm
CHARACTER*25 commands(2), argvs(2, 2)
integer nprocs(2),info(2),ncpus
c
call mpi_init(error)
c
ncpus = 2
c
commands(1) = ' ./spray '
nprocs(1) = 1
info(1) = MPI_INFO_NULL
argvs(1, 1) = ' 1 2 3 4 '
argvs(1, 2) = ' '
c
commands(2) = ' ./spray '
nprocs(2) = 1
info(2) = MPI_INFO_NULL
argvs(2, 1) = ' 4 5 6 7 '
argvs(2, 2) = ' '
c
call mpi_comm_spawn_multiple( ncpus,
1 commands, argvs, nprocs, info,
2 0, MPI_COMM_WORLD, intercomm,
3 MPI_ERRCODES_IGNORE, error )
c
call mpi_finalize(error)
c
end
Slave program (started by the controlling program) spray.F
program main
integer error
integer pid
character*20 line(100)
call mpi_init(error)
c
CALL MPI_COMM_SIZE(MPI_COMM_WORLD,NSIZE,error)
CALL MPI_COMM_RANK(MPI_COMM_WORLD,MYTID,error)
c
iargs=iargc()
write(*,*) 'nsize, mytid: iargs', nsize, mytid, ":", iargs
c
if( iargs.gt.0 ) then
do i = 1, iargs
call getarg(i,line(i))
write(*,'(1x,a,i3,20(i2,1h:,a))')
1 'spray: ',mytid,i,line(i)
enddo
endif
c
call mpi_finalize(error)
c
end
