Error using BoomerAMG with eqns

[Satish Balay]

you should just use a debugger to determine where/why you get a segv

Satish


On Tue, 10 Jun 2008, Ben Tay wrote:

> Hi,
> 
> I tried to use BoomerAMG as the preconditioner. When I use ./a.out -pc_type
> hypre -pc_hypre_type boomeramg, I got
> 
> KSP Object:
>  type: richardson
>    Richardson: damping factor=1
>  maximum iterations=10000, initial guess is zero
>  tolerances:  relative=1e-05, absolute=1e-50, divergence=10000
>  left preconditioning
> PC Object:
>  type: hypre
>    HYPRE BoomerAMG preconditioning
>    HYPRE BoomerAMG: Cycle type V
>    HYPRE BoomerAMG: Maximum number of levels 25
>    HYPRE BoomerAMG: Maximum number of iterations PER hypre call 1
>    HYPRE BoomerAMG: Convergence tolerance PER hypre call 0
>    HYPRE BoomerAMG: Threshold for strong coupling 0.25
>    HYPRE BoomerAMG: Interpolation truncation factor 0
>    HYPRE BoomerAMG: Interpolation: max elements per row 0
>    HYPRE BoomerAMG: Number of levels of aggressive coarsening 0
>    HYPRE BoomerAMG: Number of paths for aggressive coarsening 1
> 
> However, when I add the BoomerAMG into my code, I got
> 
> [3]PETSC ERROR:
> ------------------------------------------------------------------------
> [3]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, probably
> memory access out of range
> [3]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger
> [3]PETSC ERROR: or see
> http://www.mcs.anl.gov/petsc/petsc-as/documentation/troubleshooting.html#Signal[3]PETSC
> ERROR: or try http://valgrind.org on linux or man libgmalloc on Apple to find
> memory corruption errors
> [3]PETSC ERROR: configure using --with-debugging=yes, recompile, link, and run
> [3]PETSC ERROR: to get more information on the crash.
> [3]PETSC ERROR: --------------------- Error Message
> ------------------------------------
> [3]PETSC ERROR: Signal received!
> [3]PETSC ERROR:
> ------------------------------------------------------------------------
> [3]PETSC ERROR: Petsc Release Version 2.3.3, Patch 8, Fri Nov 16 17:03:40 CST
> 2007 HG revision: 414581156e67e55c761739b0deb119f7590d0f4b
> [3]PETSC ERROR: See docs/changes/index.html for recent updates.
> [3]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
> [3]PETSC ERROR: See docs/index.html for manual pages.
> [3]PETSC ERROR:
> ------------------------------------------------------------------------
> [3]PETSC ERROR: ./a.out on a atlas3-mp named atlas3-c36 by g0306332 Tue Jun 10
> 10:36:34 2008
> [3]PETSC ERROR: Libraries linked from
> /nfs/home/enduser/g0306332/petsc-2.3.3-p8/lib/atlas3-mpi
> [3]PETSC ERROR: Configure run at Tue Jan  8 22:22:08 2008
> 
> 
> Here's part of my code:
> 
> call MatAssemblyBegin(A_mat_uv,MAT_FINAL_ASSEMBLY,ierr)
> call MatAssemblyEnd(A_mat_uv,MAT_FINAL_ASSEMBLY,ierr)
> 
> call VecAssemblyBegin(b_rhs_uv,ierr)
> call VecAssemblyEnd(b_rhs_uv,ierr)
> 
> call VecAssemblyBegin(xx_uv,ierr)
> call VecAssemblyEnd(xx_uv,ierr)
> 
> call KSPSetOperators(ksp_uv,A_mat_uv,A_mat_uv,SAME_NONZERO_PATTERN,ierr)
> 
> call KSPGetPC(ksp_uv,pc_uv,ierr)
> 
> ksptype=KSPRICHARDSON
> 
> call KSPSetType(ksp_uv,ksptype,ierr)
> 
> call PCSetType(pc,'hypre',ierr)
> 
> call PCHYPRESetType(pc,'boomeramg',ierr)
> 
> call KSPSetFromOptions(ksp_uv,ierr)
> 
> tol=1.e-5
> 
> call
> KSPSetTolerances(ksp_uv,tol,PETSC_DEFAULT_DOUBLE_PRECISION,PETSC_DEFAULT_DOUBLE_PRECISION,PETSC_DEFAULT_INTEGER,ierr)
> 
> call KSPSolve(ksp_uv,b_rhs_uv,xx_uv,ierr)
> 
> call KSPGetConvergedReason(ksp_uv,reason,ierr)
> 
> 
> The matrix changes every timestep so I have to call the preconditioner every
> time. So what did I do wrong? Btw, the matrix is A_mat_uv, RHS is b_rhs_uv and
> the answer is xx_uv.
> 
> Thank you very much.
> 
> Regards.
> 
> 
>