Henrik,
On Wed, 10 Jan 2018 at 16:39, Smith, Barry F. <[email protected]> wrote: > > DMDA requires that there be at least 1 grid points in each direction on > each process (this simplified the implementation a huge amount but gives up > flexibility). In your case you have 16 processes in a particular direction > but a total of only 12 grid points hence not enough grid points to have at > least 1 per process. This particular implementation limitation can be overcome using PCTELESCOPE. It allows you to repartition the coarse levels onto fewer ranks. Cheers, Dave > > Barry > > > > On Jan 10, 2018, at 5:25 AM, Buesing, Henrik < > [email protected]> wrote: > > > > Dear all, > > > > I am doing a weak scaling test using geometric multigrid. With > increasing the number of cells, and the number of processes, I also > increase the number of multigrid levels. With 64 cores, 12288 cells in > x-direction and 11 multigrid levels, I see error message [1]. > > > > Could you help me understand what is happening here? > > > > The characteristics of the weak scaling test are summarized in table > [2]. Refinement level 7-9 went through fine. > > > > Thank you! > > Henrik > > > > [1] > > > > [0]PETSC ERROR: --------------------- Error Message > -------------------------------------------------------------- > > [0]PETSC ERROR: Argument out of range > > [0]PETSC ERROR: Partition in x direction is too fine! 12 16 > > [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html > for trouble shooting. > > [0]PETSC ERROR: Petsc Development GIT revision: v3.8.2-48-g851ec02 GIT > Date: 2017-12-05 09:52:17 -0600 > > [0]PETSC ERROR: shem_fw64gnu_const.x on a gnu_openmpi named > linuxihfc033.rz.RWTH-Aachen.DE by hb111949 Wed Jan 10 11:48:09 2018 > > [0]PETSC ERROR: Configure options --download-fblaslapack --with-cc=mpicc > -with-fc=mpif90 --with-cxx=mpicxx --download-hypre --download-superlu_dist > --download-suitesparse --download-scalapack --download-blacs > --download-hdf5 --download-parmetis --download-metis --with-debugging=0 > --download-mumps > > [0]PETSC ERROR: #1 DMSetUp_DA_3D() line 299 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/dm/impls/da/da3.c > > [0]PETSC ERROR: #2 DMSetUp_DA() line 25 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/dm/impls/da/dareg.c > > [0]PETSC ERROR: #3 DMSetUp() line 720 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/dm/interface/dm.c > > [0]PETSC ERROR: #4 DMCoarsen_DA() line 1203 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/dm/impls/da/da.c > > [0]PETSC ERROR: #5 DMCoarsen() line 2427 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/dm/interface/dm.c > > [0]PETSC ERROR: #6 PCSetUp_MG() line 618 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/ksp/pc/impls/mg/mg.c > > [0]PETSC ERROR: #7 PCSetUp() line 924 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/ksp/pc/interface/precon.c > > [0]PETSC ERROR: #8 KSPSetUp() line 381 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/ksp/ksp/interface/itfunc.c > > [0]PETSC ERROR: #9 KSPSolve() line 612 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/ksp/ksp/interface/itfunc.c > > [0]PETSC ERROR: #10 SNESSolve_NEWTONLS() line 224 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/snes/impls/ls/ls.c > > [0]PETSC ERROR: #11 SNESSolve() line 4179 in > /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/snes/interface/snes.c > > > > > > [2] > > > > # refinement level > > # cores > > # cells in x > > # cells in y > > # cells in z > > # mg levels > > 7 > > 1 > > 1536 > > 1 > > 256 > > 8 > > 8 > > 4 > > 3072 > > 1 > > 512 > > 9 > > 9 > > 16 > > 6144 > > 1 > > 1024 > > 10 > > 10 > > 64 > > 12288 > > 1 > > 2048 > > 11 > > > > -- > > Dipl.-Math. Henrik Büsing > > Institute for Applied Geoph > <https://maps.google.com/?q=Applied+Geoph&entry=gmail&source=g>ysics and > Geothermal Energy > > E.ON Energy Research Center > > RWTH Aachen University > > ------------------------------------------------------ > > Mathieustr. 10 | Tel +49 (0)241 80 49907 > > 52074 Aachen, Germany | Fax +49 (0)241 80 49889 > > ------------------------------------------------------ > > http://www.eonerc.rwth-aachen.de/GGE > > [email protected] > > ------------------------------------------------------ > >
