[petsc-users] ML options

[Tobin Isaac]

On Tue, Jan 08, 2013 at 08:07:36AM -0600, Jed Brown wrote:
> On Mon, Jan 7, 2013 at 4:23 PM, Mark F. Adams <mark.adams at columbia.edu>wrote:
> 
> > '-pc_ml_reuse_interpolation true' does seem to get ML to reuse some mesh
> > setup.  The setup time goes from .3 to .1 sec on one of my tests from the
> > first to the second solve.
> >
> > Hong: this looks like a way to infer ML's RAP times.  I think the second
> > solves are just redoing the RAP with this flag, like what GAMG does by
> > default.
> >
> 
> Huh, it's changing the sparsity of the coarse grid.

There's at least one part of grid generation in ml, I forget where
exactly, that computed zeros are eliminated.

> 
> $ ./ex15 -da_grid_x 20 -da_grid_y 20 -p 1.2 -ksp_converged_reason -pc_type
> ml -pc_ml_reuse_interpolation
>   Linear solve converged due to CONVERGED_RTOL iterations 6
> [0]PETSC ERROR: --------------------- Error Message
> ------------------------------------
> [0]PETSC ERROR: Argument out of range!
> [0]PETSC ERROR: New nonzero at (0,8) caused a malloc!
> [0]PETSC ERROR:
> ------------------------------------------------------------------------
> [0]PETSC ERROR: Petsc Development HG revision:
> cb29460836d903f43276d687c4ba9f5917bf6651  HG Date: Sun Jan 06 14:49:14 2013
> -0600
> [0]PETSC ERROR: See docs/changes/index.html for recent updates.
> [0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
> [0]PETSC ERROR: See docs/index.html for manual pages.
> [0]PETSC ERROR:
> ------------------------------------------------------------------------
> [0]PETSC ERROR: ./ex15 on a mpich named batura by jed Tue Jan  8 08:06:37
> 2013
> [0]PETSC ERROR: Libraries linked from /home/jed/petsc/mpich/lib
> [0]PETSC ERROR: Configure run at Sun Jan  6 15:19:56 2013
> [0]PETSC ERROR: Configure options --download-ams --download-blacs
> --download-chaco --download-generator --download-hypre --download-ml
> --download-spai --download-spooles --download-sundials --download-superlu
> --download-superlu_dist --download-triangle --with-blas-lapack=/usr
> --with-c2html --with-cholmod-dir=/usr
> --with-clique-dir=/home/jed/usr/clique-mpich
> --with-elemental-dir=/home/jed/usr/clique-mpich --with-exodusii-dir=/usr
> --with-hdf5-dir=/opt/mpich --with-lgrind
> --with-metis-dir=/home/jed/usr/clique-mpich --with-mpi-dir=/opt/mpich
> --with-netcdf-dir=/usr --with-openmp
> --with-parmetis-dir=/home/jed/usr/clique-mpich --with-pcbddc
> --with-pthreadclasses --with-shared-libraries --with-single-library=0
> --with-sowing --with-threadcomm --with-umfpack-dir=/usr --with-x
> -PETSC_ARCH=mpich
> [0]PETSC ERROR:
> ------------------------------------------------------------------------
> [0]PETSC ERROR: MatSetValues_SeqAIJ() line 352 in
> /home/jed/petsc/src/mat/impls/aij/seq/aij.c
> [0]PETSC ERROR: MatSetValues() line 1083 in
> /home/jed/petsc/src/mat/interface/matrix.c
> [0]PETSC ERROR: MatWrapML_SeqAIJ() line 348 in
> /home/jed/petsc/src/ksp/pc/impls/ml/ml.c
> [0]PETSC ERROR: PCSetUp_ML() line 639 in
> /home/jed/petsc/src/ksp/pc/impls/ml/ml.c
> [0]PETSC ERROR: PCSetUp() line 832 in
> /home/jed/petsc/src/ksp/pc/interface/precon.c
> [0]PETSC ERROR: KSPSetUp() line 267 in
> /home/jed/petsc/src/ksp/ksp/interface/itfunc.c
> [0]PETSC ERROR: KSPSolve() line 376 in
> /home/jed/petsc/src/ksp/ksp/interface/itfunc.c
> [0]PETSC ERROR: SNES_KSPSolve() line 4460 in
> /home/jed/petsc/src/snes/interface/snes.c
> [0]PETSC ERROR: SNESSolve_NEWTONLS() line 216 in
> /home/jed/petsc/src/snes/impls/ls/ls.c
> [0]PETSC ERROR: SNESSolve() line 3678 in
> /home/jed/petsc/src/snes/interface/snes.c
> [0]PETSC ERROR: main() line 221 in src/snes/examples/tutorials/ex15.c
> application called MPI_Abort(MPI_COMM_WORLD, 63) - process 0