[petsc-users] Using GAMG to speed up solving of Poisson eqn

TAY wee-beng zonexo at gmail.com
Sat Jul 20 10:45:16 CDT 2013


On 20/7/2013 4:08 PM, Matthew Knepley wrote:
> On Sat, Jul 20, 2013 at 8:39 AM, TAY wee-beng <zonexo at gmail.com 
> <mailto:zonexo at gmail.com>> wrote:
>
>     Hi,
>
>     I'm trying to use GAMG to speed up solving of Poisson eqn. I used:
>
>     call KSPSetOptionsPrefix(ksp,"poisson_",ierr)
>
>     -poisson_pc_gamg_agg_nsmooths 1 -poisson_pc_type gamg
>
>     I remember it used to work in some problems but now it can't work,
>     with error:
>
>
> Upgrade to the latest release and we will help you debug this.
>
>    Matt
Hi Matt,

I've used the latest 3.4.2.  What else do I need to provide?

Thanks!
>
>     */[0]PETSC ERROR:
>     ------------------------------------------------------------------------/**/
>     /**/[0]PETSC ERROR: Caught signal number 8 FPE: Floating Point
>     Exception,probably divide by zero/**/
>     /**/[0]PETSC ERROR: Try option -start_in_debugger or
>     -on_error_attach_debugger/**/
>     /**/[0]PETSC ERROR: or see
>     http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind[0]PETSC
>     ERROR: or try http://valgrind.org on GNU/linux and Apple Mac OS X
>     to find memory corruption errors/**/
>     /**/[0]PETSC ERROR: likely location of problem given in stack
>     below/**/
>     /**/[0]PETSC ERROR: --------------------- Stack Frames
>     ------------------------------------/**/
>     /**/[0]PETSC ERROR: Note: The EXACT line numbers in the stack are
>     not available,/**/
>     /**/[0]PETSC ERROR:       INSTEAD the line number of the start of
>     the function/**/
>     /**/[0]PETSC ERROR:       is given./**/
>     /**/[0]PETSC ERROR: [0] KSPComputeExtremeSingularValues_GMRES line
>     24
>     src/ksp/ksp/impls/gmres/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\impls\gmres\gmreig.c/**/
>     /**/[0]PETSC ERROR: [0] KSPComputeExtremeSingularValues line 40
>     src/ksp/ksp/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c/**/
>     /**/[0]PETSC ERROR: [0] PCGAMGOptprol_AGG line 1295
>     src/ksp/pc/impls/gamg/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\pc\impls\gamg\agg.c/**/
>     /**/[0]PETSC ERROR: [0] PCSetUp_GAMG line 564
>     src/ksp/pc/impls/gamg/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\pc\impls\gamg\gamg.c/**/
>     /**/[0]PETSC ERROR: [0] PCSetUp line 810
>     src/ksp/pc/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\pc\INTERF~1\precon.c/**/
>     /**/[0]PETSC ERROR: [0] KSPSetUp line 182
>     src/ksp/ksp/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c/**/
>     /**/[0]PETSC ERROR: [0] KSPSolve line 351
>     src/ksp/ksp/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c/**/
>     /**/[0]PETSC ERROR: --------------------- Error Message
>     ------------------------------------/**/
>     /**/[0]PETSC ERROR: Signal received!/**/
>     /**/[0]PETSC ERROR:
>     ------------------------------------------------------------------------/**/
>     /**/[0]PETSC ERROR: Petsc Development HG revision:
>     9850aeb5d33f0b33bc931843c4b3b3b4f8df6a3b HG Date: Tue Oct 02
>     22:18:53 2012 -0500/**/
>     /**/[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:
>     C:\Obj_tmp\ibm3d_high_Re_staggered_AB2\Debug\ibm3d_high_Re_staggered_AB2.exe
>     on a petsc-3.3 named USER-PC by User Sat Jul 20 15:37:40 2013/**/
>     /**/[0]PETSC ERROR: Libraries linked from
>     /cygdrive/d/wtay/Lib/petsc-3.3-dev_win32_vs2008/lib/**/
>     /**/[0]PETSC ERROR: Configure run at Thu Oct  4 10:01:13 2012/**/
>     /**/[0]PETSC ERROR: Configure options --with-cc="win32fe cl"
>     --with-fc="win32fe ifort" --with-cxx="win32fe cl"
>     --with-mpi-dir=/cygdrive/c/MPICH2/ --download-f-blas-lapack=1
>     --prefix=/cygdrive/d/wtay/Lib/petsc-3.3-dev_win32_vs2008
>     --with-debugging=1 --useThreads=0/**/
>     /**/[0]PETSC ERROR:
>     ------------------------------------------------------------------------/**/
>     /**/[0]PETSC ERROR: User provided function() line 0 in unknown
>     directory unknown file/**/
>     /**/application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0/**/
>     /**/
>     /**/job aborted:/**/
>     /**/rank: node: exit code[: error message]/**/
>     /**/0: User-PC: 59: process 0 exited without calling finalize/*/
>     /
>
>     I read in one of the threads that I can use:
>
>     -pc_type gamg -pc_gamg_agg_nsmooths 1 -mg_levels_ksp_type
>     richardson -mg_levels_pc_type sor
>
>     It worked but I got the msg:
>
>     WARNING! There are options you set that were not used!
>     WARNING! could be spelling mistake, etc!
>     Option left: name:-mg_levels_ksp_type value: richardson
>     Option left: name:-mg_levels_pc_type value: sor
>     Option left: name:-pc_gamg_agg_nsmooths value: 1
>     Option left: name:-pc_type value: gamg
>     Press any key to continue . . .
>
>     If I used this:
>
>     -poisson_pc_type gamg -poisson_pc_gamg_agg_nsmooths 1
>     -poisson_mg_levels_ksp_type richardson -poisson_mg_levels_pc_type sor
>
>     It aborts with error:
>
>     */[0]PETSC ERROR:
>     ------------------------------------------------------------------------/**/
>     /**/[0]PETSC ERROR: Caught signal number 8 FPE: Floating Point
>     Exception,probably divide by zero/**/
>     /**/[0]PETSC ERROR: Try option -start_in_debugger or
>     -on_error_attach_debugger/**/
>     /**/[0]PETSC ERROR: or see
>     http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind[0]PETSC
>     ERROR: or try http://valgrind.org on GNU/linux and Apple Mac OS X
>     to find memory corruption errors/**/
>     /**/[0]PETSC ERROR: likely location of problem given in stack
>     below/**/
>     /**/[0]PETSC ERROR: --------------------- Stack Frames
>     ------------------------------------/**/
>     /**/[0]PETSC ERROR: Note: The EXACT line numbers in the stack are
>     not available,/**/
>     /**/[0]PETSC ERROR:       INSTEAD the line number of the start of
>     the function/**/
>     /**/[0]PETSC ERROR:       is given./**/
>     /**/[0]PETSC ERROR: [0] KSPComputeExtremeSingularValues_GMRES line
>     24
>     src/ksp/ksp/impls/gmres/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\impls\gmres\gmreig.c/**/
>     /**/[0]PETSC ERROR: [0] KSPComputeExtremeSingularValues line 40
>     src/ksp/ksp/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c/**/
>     /**/[0]PETSC ERROR: [0] PCGAMGOptprol_AGG line 1295
>     src/ksp/pc/impls/gamg/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\pc\impls\gamg\agg.c/**/
>     /**/[0]PETSC ERROR: [0] PCSetUp_GAMG line 564
>     src/ksp/pc/impls/gamg/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\pc\impls\gamg\gamg.c/**/
>     /**/[0]PETSC ERROR: [0] PCSetUp line 810
>     src/ksp/pc/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\pc\INTERF~1\precon.c/**/
>     /**/[0]PETSC ERROR: [0] KSPSetUp line 182
>     src/ksp/ksp/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c/**/
>     /**/[0]PETSC ERROR: [0] KSPSolve line 351
>     src/ksp/ksp/interface/C:\wtay\DOWNLO~1\Codes\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c/**/
>     /**/[0]PETSC ERROR: --------------------- Error Message
>     ------------------------------------/**/
>     /**/[0]PETSC ERROR: Signal received!/**/
>     /**/[0]PETSC ERROR:
>     ------------------------------------------------------------------------/**/
>     /**/[0]PETSC ERROR: Petsc Development HG revision:
>     9850aeb5d33f0b33bc931843c4b3b3b4f8df6a3b HG Date: Tue Oct 02
>     22:18:53 2012 -0500/**/
>     /**/[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:
>     C:\Obj_tmp\ibm3d_high_Re_staggered_AB2\Debug\ibm3d_high_Re_staggered_AB2.exe
>     on a petsc-3.3 named USER-PC by User Sat Jul 20 15:36:24 2013/**/
>     /**/[0]PETSC ERROR: Libraries linked from
>     /cygdrive/d/wtay/Lib/petsc-3.3-dev_win32_vs2008/lib/**/
>     /**/[0]PETSC ERROR: Configure run at Thu Oct  4 10:01:13 2012/**/
>     /**/[0]PETSC ERROR: Configure options --with-cc="win32fe cl"
>     --with-fc="win32fe ifort" --with-cxx="win32fe cl"
>     --with-mpi-dir=/cygdrive/c/MPICH2/ --download-f-blas-lapack=1
>     --prefix=/cygdrive/d/wtay/Lib/petsc-3.3-dev_win32_vs2008
>     --with-debugging=1 --useThreads=0/**/
>     /**/[0]PETSC ERROR:
>     ------------------------------------------------------------------------/**/
>     /**/[0]PETSC ERROR: User provided function() line 0 in unknown
>     directory unknown file/**/
>     /**/application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0/**/
>     /**/
>     /**/job aborted:/**/
>     /**/rank: node: exit code[: error message]/**/
>     /**/0: User-PC: 59: process 0 exited without calling finalize/**/
>     /*
>
>
>     So is there a recommended test command or method?
>
>     Thank!
>
>     -- 
>     Yours sincerely,
>
>     TAY wee-beng
>
>
>
>
> -- 
> What most experimenters take for granted before they begin their 
> experiments is infinitely more interesting than any results to which 
> their experiments lead.
> -- Norbert Wiener

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