MPICH error when using petsc-3.0.0-p4

[Satish Balay]

(--with-scalar-type=[real,complex], --with-precision=[single,double])

Depending upon how petsc is configured - PetscScalar can be either
real4,real8,complex8. With most common usage - [i.e default build]
PetscScalar is real8.

Earlier you claimed: MPI_ISEND(v_ast) worked with MPI_REAL but not
MPI_REAL8. This sugested that v_ast was declared as real4 - not real8.

Satish

On Tue, 14 Apr 2009, Wee-Beng TAY wrote:

> Hi,
> 
> So when must I use PetscScalar, and when can I just use real(8)? This is
> because most of my variables are in real(8), except for the Mat, Vec, required
> in the solving of the linear eqn. Is there a rule? I initially thought they
> are the same and if I remember correctly, it seems to work fine in PETSc2.3.3.
> 
> My v_ast is now defined as:
> 
> PetscScalar, allocatable ::    u_ast(:,:), v_ast(:,:)
> 
> allocate (u_ast(0:size_x+1,jsta_ext:jend_ext), STAT=status(1));allocate
> (v_ast(0:size_x+1,jsta_ext:jend_ext), STAT=status(2))
> 
> if (status(1)/=0 .or. status(2)/=0) STOP "Cannot allocate memory"
> 
> Thank you very much and have a nice day!
> 
> Yours sincerely,
> 
> Wee-Beng Tay
> 
> 
> 
> Satish Balay wrote:
> > And if v_ast() is used with PETSc - then it should be defined 'PetscScalar'
> > 
> > and then you use MPI_ISEND(....,MPIU_SCALAR,...)
> > 
> > Satish
> > 
> > 
> > On Mon, 13 Apr 2009, Barry Smith wrote:
> > 
> >   
> > >   Where is your implicit none that all sane programmers begin their
> > > Fortran
> > > subroutines with?
> > > 
> > > 
> > > On Apr 13, 2009, at 11:11 AM, Wee-Beng TAY wrote:
> > > 
> > >     
> > > > Hi Satish,
> > > > 
> > > > Compiling and building now worked without error. However, when I run, I
> > > > get
> > > > the error:
> > > > 
> > > > 0 - MPI_ISEND : Datatype is MPI_TYPE_NULL
> > > > [0]  Aborting program !
> > > > [0] Aborting program!
> > > > Error 323, process 0, host GOTCHAMA-E73BB3:
> > > > 
> > > > The problem lies in this subroutine:
> > > > 
> > > > subroutine v_ast_row_copy
> > > > 
> > > > #include "finclude/petsc.h"
> > > > #include "finclude/petscvec.h"
> > > > #include "finclude/petscmat.h"
> > > > #include "finclude/petscksp.h"
> > > > #include "finclude/petscpc.h"
> > > > #include "finclude/petscsys.h"
> > > > 
> > > > !to copy data of jend row to others
> > > > 
> > > > integer :: inext,iprev,istatus(MPI_STATUS_SIZE),irecv1,ierr,isend1
> > > > 
> > > > inext = myid + 1
> > > > iprev = myid - 1
> > > > 
> > > > if (myid == num_procs - 1) inext = MPI_PROC_NULL
> > > > 
> > > > if (myid == 0) iprev = MPI_PROC_NULL
> > > > 
> > > > CALL
> > > > MPI_ISEND(v_ast(1,jend),size_x,MPI_REAL8,inext,1,MPI_COMM_WORLD,isend1,ierr)
> > > > CALL
> > > > MPI_IRECV(v_ast(1,jsta-1),size_x,MPI_REAL8,iprev,1,MPI_COMM_WORLD,irecv1,ierr)
> > > > CALL MPI_WAIT(isend1, istatus, ierr)
> > > > CALL MPI_WAIT(irecv1, istatus, ierr)
> > > > 
> > > > end subroutine v_ast_row_copy
> > > > 
> > > > 
> > > > I copied this subroutine from the RS6000 mpi manual and it used to work.
> > > > I
> > > > wonder if this is a MPI or PETSc problem? Strange because I already
> > > > specify
> > > > the type to be MPI_REAL8. However changing to MPI_REAL solves the
> > > > problem.
> > > > 
> > > > If this is a MPI problem, then you can just ignore it. I'll check it in
> > > > some
> > > > MPI forum.
> > > > 
> > > > 
> > > > Thank you very much and have a nice day!
> > > > 
> > > > Yours sincerely,
> > > > 
> > > > Wee-Beng Tay