Hello,
I am using a Fortran 90 CFD code on a Linux cluster (AMD64 K8 proc.).
The fortran compiler is PathScale and we also use LAM-MPI . We compile
with pathf90 and include the link to all the MPI libraries.
I am experiencing problems with MPI_Allreduce Calls. The compilation is
successful, but the run stops with the following error message:
MPI_Allreduce: invalid operation: Invalid argument (rank 0,
MPI_COMM_WORLD)
Rank (0, MPI_COMM_WORLD): Call stack within LAM:
Rank (0, MPI_COMM_WORLD): - MPI_Allreduce()
Rank (0, MPI_COMM_WORLD): - main()
There are 2 types of MPI_Allreduce calls, typically:
call MPI_Allreduce(tstep_l,tstep_g,
1,MPI_2DOUBLE_PRECISION,MPI_MINLOC,gcomm,ierr)
call MPI_Allreduce(rkerr_l,rkerr_g, 1,MPI_REAL8,MPI_MIN,gcomm,ierr)
These data_types are listed in LAM/MPI docs, how can it not recognize
them?
I have also seen MPI_Allreduce calls with 8 arguments instead of 7, the
extra argument being a '0' (integer) before 'gcomm' (i.e. call
MPI_Allreduce(rkerr_l,rkerr_g, 1,MPI_REAL8,MPI_MIN,0,gcomm,ierr).
Please see the example on the following link:
http://www.mpi-forum.org/docs/mpi-11-html/node82.html#Node82
Thanks a lot for any clarification on (or suggestion to solve this)
MPI_Allreduce error.
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Carlos CRUZ
Univ. Maryland, College Park
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