Hi Everyone I am trying to replicate the type of preconditioner described in "Hierarchical and Nested Krylov Methods for Extreme-Scale Computing".
I have used the following options: (I'm using fortran so the following is my petsc_options file) # Matrix Options -matload_block_size 5 -mat_type mpibaij # KSP solver options -ksp_type gmres -ksp_max_it 1000 -ksp_gmres_restart 200 -ksp_monitor -ksp_view -ksp_pc_side right -ksp_rtol 1e-6 # Nested GMRES Options -pc_type bjacobi -pc_bjacobi_blocks 4 -sub_ksp_type gmres -sub_ksp_max_it 5 -sub_pc_type bjacobi -sub_sub_pc_type ilu -sub_sub_pc_factor_mat_ordering_type rcm -sub_sub_pc_factor_levels 1 The test is run on 64 processors and the total number of block jacobi blocks is 4 (less than nproc). The error I get is: [6]PETSC ERROR: Note: The EXACT line numbers in the stack are not available, [6]PETSC ERROR: INSTEAD the line number of the start of the function [6]PETSC ERROR: is given. [6]PETSC ERROR: [6] PCSetUp_BJacobi_Multiproc line 1269 /home/j/jmartins/kenway/packages/petsc-3.3-p5/src/ksp/pc/impls/bjacobi/bjacobi.c [6]PETSC ERROR: [6] PCSetUp_BJacobi line 24 /home/j/jmartins/kenway/packages/petsc-3.3-p5/src/ksp/pc/impls/bjacobi/bjacobi.c [6]PETSC ERROR: [6] PCSetUp line 810 /home/j/jmartins/kenway/packages/petsc-3.3-p5/src/ksp/pc/interface/precon.c [6]PETSC ERROR: [6] KSPSetUp line 182 /home/j/jmartins/kenway/packages/petsc-3.3-p5/src/ksp/ksp/interface/itfunc.c [6]PETSC ERROR: [6] KSPSolve line 351 /home/j/jmartins/kenway/packages/petsc-3.3-p5/src/ksp/ksp/interface/itfunc.c [6]PETSC ERROR: --------------------- Error Message ------------------------------------ [6]PETSC ERROR: Signal received! [6]PETSC ERROR: ------------------------------------------------------------------------ [6]PETSC ERROR: Petsc Release Version 3.3.0, Patch 5, Sat Dec 1 15:10:41 CST 2012 [6]PETSC ERROR: See docs/changes/index.html for recent updates. [6]PETSC ERROR: See docs/faq.html for hints about trouble shooting. [6]PETSC ERROR: ------------------------------------------------------------------------ [6]PETSC ERROR: ------------------------------------------------------------------------ [6]PETSC ERROR: ./main on a intel-rea named gpc-f109n001 by kenway Sun May 19 23:01:52 2013 [6]PETSC ERROR: Libraries linked from /home/j/jmartins/kenway/packages/petsc-3.3-p5/intel-real-debug/lib [6]PETSC ERROR: Configure run at Sun Jan 20 15:52:20 2013 [6]PETSC ERROR: Configure options --with-shared-libraries --download-superlu_dist=yes --download-parmetis=yes --download-metis=yes --with-fortran-interfaces=1 --with-debugging=yes --with-scalar-type=real -with-petsc-arch=intel-real-debug --with-blas-lapack-dir= --with-pic [6]PETSC ERROR: ------------------------------------------------------------------------ If the number of blocks is greater than or equal to the number of processors it runs fine. I'm using version 3.3-p5. The options as listed in the paper are: -flow_ksp_type fgmres -flow_ksp_pc_side right -flow_pc_type bjacobi -flow_pc_bjacobi_blocks ngp -flow_sub_ksp_type gmres -flow_sub_ksp_max_it 6 -flow_sub_pc_type bjacobi -flow_sub_sub_pc_type ilu Any suggestions would be greatly appreciated. Thank you, Gaetan Kenway
