[petsc-users] Using MUMPS solver with PETSc

[Ajit Desai]

Hello everyone,

I am trying to use PETSc-MUMPS solver to solve linear problem of type "A x
= b "
I have wrote a subroutine in Fortran 90 for uni-processor. given below.
I am calling this subroutine inside iterative solver.

This solver is very fast for first few iterations but then becomes slow and
if matrix is of large-scale, it becomes very-very slow.

If somebody can help me to understand, if I am doing something wrong here?

Thanks you.

!!!*************************************************

!!! Subroutine

SUBROUTINE PETScMUMPS(ksp,pc,A,x,b,ierr)


#include <petsc/finclude/petscsys.h>

#include <petsc/finclude/petscvec.h>

#include <petsc/finclude/petscmat.h>

#include <petsc/finclude/petscksp.h>

#include <petsc/finclude/petscpc.h>


Vec              x,b

Mat              A

KSP              ksp

PC               pc


Mat              F

PetscInt         ival,icntl


PetscErrorCode   ierr


    call KSPCreate(PETSC_COMM_SELF,ksp,ierr)

    call KSPSetOperators(ksp,A,A,ierr)

    call KSPSetType(ksp,KSPPREONLY,ierr)

    call KSPGetPC(ksp,pc,ierr)


    !call PCSetType(pc,PCLU,ierr)           !! LU Factorization

    call PCSetType(pc,PCCHOLESKY,ierr)     !! Cholesky Factorization


    call PCFactorSetMatSolverPackage(pc,MATSOLVERMUMPS,ierr)

    call PCFactorSetUpMatSolverPackage(pc,ierr)

    call PCFactorGetMatrix(pc,F,ierr)


    !! sequential ordering

    icntl = 7

    ival  = 2

    call MatMumpsSetIcntl(F,icntl,ival,ierr)


    call KSPSetFromOptions(ksp,ierr)

    call KSPGetPC(ksp,pc,ierr)


    call KSPSolve(ksp,x,b,ierr)


END SUBROUTINE PETScMUMPS

!!!*************************************************



*Ajit Desai*
*--*
*  PhD Scholar, Carleton University *
*  Ottawa, Canada*
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20160305/166717d2/attachment.html>