Is this the bad interaction Jed found between PCMG and ML?<div><br></div><div> Matt<br><br><div class="gmail_quote">On Wed, Jun 29, 2011 at 12:45 PM, <span dir="ltr"><<a href="mailto:domenico.borzacchiello@univ-st-etienne.fr">domenico.borzacchiello@univ-st-etienne.fr</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Hi,<br>
I use ML as a preconditioner for the pressure poisson equation for Stokes<br>
problem. I solve for the pressure at each time step with ad DMMGSolve on<br>
the whole (Stokes) system. I randomly get the following error at some<br>
point.<br>
<br>
[0]PETSC ERROR: --------------------- Error Message<br>
------------------------------------<br>
[0]PETSC ERROR: Operation done in wrong order!<br>
[0]PETSC ERROR: Number levels already set for MG<br>
make sure that you call PCMGSetLevels() before KSPSetFromOptions()!<br>
[0]PETSC ERROR:<br>
------------------------------------------------------------------------<br>
[0]PETSC ERROR: Petsc Development HG revision:<br>
d1471993ab06fb6a9072f156c420ef0a456a086c HG Date: Sun May 01 09:59:41<br>
2011 -0500<br>
[0]PETSC ERROR: See docs/changes/index.html for recent updates.<br>
[0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.<br>
[0]PETSC ERROR: See docs/index.html for manual pages.<br>
[0]PETSC ERROR:<br>
------------------------------------------------------------------------<br>
[0]PETSC ERROR: ./2dbphlow on a arch-linu named<br>
domenico-Dell-System-XPS-L502X by domenico Wed Jun 29 14:32:00 2011<br>
[0]PETSC ERROR: Libraries linked from /opt/petsc-dev/arch-linux2-c-debug/lib<br>
[0]PETSC ERROR: Configure run at Thu May 5 03:28:56 2011<br>
[0]PETSC ERROR: Configure options --with-cc=icc --with-fc=ifort<br>
--download-f-blas-lapack=1 --download-mpich=1 --download-superlu_dist<br>
--download-parmetis --download-mumps --download-blacs --download-scalapack<br>
--download-hypre --download-ml --with-c2html=0 --download-prometheus<br>
--download-parms<br>
[0]PETSC ERROR:<br>
------------------------------------------------------------------------<br>
[0]PETSC ERROR: PCMGSetLevels() line 151 in src/ksp/pc/impls/mg/mg.c<br>
[0]PETSC ERROR: PCSetUp_ML() line 610 in src/ksp/pc/impls/ml/ml.c<br>
[0]PETSC ERROR: PCSetUp() line 819 in src/ksp/pc/interface/precon.c<br>
[0]PETSC ERROR: KSPSetUp() line 261 in src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: KSPSolve() line 383 in src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: PCApply_LSC() line 85 in src/ksp/pc/impls/lsc/lsc.c<br>
[0]PETSC ERROR: PCApply() line 383 in src/ksp/pc/interface/precon.c<br>
[0]PETSC ERROR: FGMREScycle() line 174 in<br>
src/ksp/ksp/impls/gmres/fgmres/fgmres.c<br>
[0]PETSC ERROR: KSPSolve_FGMRES() line 300 in<br>
src/ksp/ksp/impls/gmres/fgmres/fgmres.c<br>
[0]PETSC ERROR: KSPSolve() line 426 in src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: PCApply_FieldSplit_Schur() line 572 in<br>
src/ksp/pc/impls/fieldsplit/fieldsplit.c<br>
[0]PETSC ERROR: PCApply() line 383 in src/ksp/pc/interface/precon.c<br>
[0]PETSC ERROR: FGMREScycle() line 174 in<br>
src/ksp/ksp/impls/gmres/fgmres/fgmres.c<br>
[0]PETSC ERROR: KSPSolve_FGMRES() line 300 in<br>
src/ksp/ksp/impls/gmres/fgmres/fgmres.c<br>
[0]PETSC ERROR: KSPSolve() line 426 in src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: SNES_KSPSolve() line 3124 in src/snes/interface/snes.c<br>
[0]PETSC ERROR: SNESSolve_LS() line 190 in src/snes/impls/ls/ls.c<br>
[0]PETSC ERROR: SNESSolve() line 2424 in src/snes/interface/snes.c<br>
[0]PETSC ERROR: DMMGSolveSNES() line 503 in src/snes/utils/damgsnes.c<br>
[0]PETSC ERROR: DMMGSolve() line 313 in src/snes/utils/damg.c<br>
[0]PETSC ERROR: main() line 726 in 2dbphlow.c<br>
application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0<br>
[cli_0]: aborting job:<br>
application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0<br>
<br>
=====================================================================================<br>
= BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES<br>
= EXIT CODE: 256<br>
= CLEANING UP REMAINING PROCESSES<br>
= YOU CAN IGNORE THE BELOW CLEANUP MESSAGES<br>
=====================================================================================<br>
<br>
<br>
I don't know the reason for it, it occurs at some random timestep if I<br>
change any of the input parameters like the viscosity, the geometry, the<br>
mesh size etc... Sometimes it just doesn't occur at all.<br>
<br>
ML is used with the following options:<br>
<br>
<br>
-stokes_fieldsplit_pressure_lsc_pc_type ml \<br>
-stokes_fieldsplit_pressure_lsc_pc_ml_maxCoarseSize 1 \<br>
-stokes_fieldsplit_pressure_lsc_pc_ml_Threshold 0.009 \<br>
-stokes_fieldsplit_pressure_lsc_pc_ml_Symmetrize\<br>
-stokes_fieldsplit_pressure_lsc_pc_ml_KeepAggInfo\<br>
-stokes_fieldsplit_pressure_lsc_pc_ml_Reusable\<br>
-stokes_fieldsplit_pressure_lsc_pc_ml_DampingFactor 1.3333 \<br>
<br>
Any idea?<br>
<br>
<br>
<br>
<br>
</blockquote></div><br><br clear="all"><br>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener<br>
</div>