MPICH error when using petsc-3.0.0-p4

[Wee-Beng TAY]

Hi Satish,

That's strange. This is because I initially declared u_ast as

real(8), allocatable ::  u_ast(:,:)

I also have the -r8 option enabled. Any idea what is going on?

Thank you very much and have a nice day!

Yours sincerely,

Wee-Beng Tay



Satish Balay wrote:
> (--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
>>>>>           
>
>