[petsc-users] Re-configuring PETSc

[Smith, Barry F.]

> On May 28, 2018, at 9:58 AM, Najeeb Ahmad <nahmad16 at ku.edu.tr> wrote:
> 
> Hi All,
> 
> I have Petsc release version 3.9.2 configured with the following options:
> 
> Configure options --with-cc=mpiicc --with-cxx=mpiicpc --with-fc=mpiifort --download-fblaslapack=1
> 
> Now I want to use PCILU in my code and when I set the PC type to PCILU in the code, I get the following error:
> 
> [0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------
> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/linearsolvertable.html for possible LU and Cholesky solvers
> [0]PETSC ERROR: Could not locate a solver package. Perhaps you must ./configure with --download-<package>
> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
> [0]PETSC ERROR: Petsc Release Version 3.9.2, unknown
> [0]PETSC ERROR: ./main on a arch-linux2-c-debug named Karachi by nahmad Mon May 28 17:52:41 2018
> [0]PETSC ERROR: Configure options --with-cc=mpiicc --with-cxx=mpiicpc --with-fc=mpiifort --download-fblaslapack=1
> [0]PETSC ERROR: #1 MatGetFactor() line 4318 in /home/nahmad/PETSc/petsc/src/mat/interface/matrix.c
> [0]PETSC ERROR: #2 PCSetUp_ILU() line 142 in /home/nahmad/PETSc/petsc/src/ksp/pc/impls/factor/ilu/ilu.c
> [0]PETSC ERROR: #3 PCSetUp() line 923 in /home/nahmad/PETSc/petsc/src/ksp/pc/interface/precon.c
> [0]PETSC ERROR: #4 KSPSetUp() line 381 in /home/nahmad/PETSc/petsc/src/ksp/ksp/interface/itfunc.c
> [0]PETSC ERROR: #5 KSPSolve() line 612 in /home/nahmad/PETSc/petsc/src/ksp/ksp/interface/itfunc.c
> [0]PETSC ERROR: #6 SolveSystem() line 60 in /home/nahmad/Aramco/petsc/petsc/BlockSolveTest/src/main.c
> 
> 
> I assume that I am missing LU package like SuperLU_dist for instance and I need to download and configure it with Petsc.
> 
> I am wondering what is the best way to reconfigure Petsc to download and use the appropriate package to support PCILU?

    There is no support for parallel ILU in PETSc (or with its external packages). You can use -pc_type bjacobi or -pc_type asm  and -sub_pc_type ilu and get block Jacobi or overlapping additive Schwarz with ILU on each block (which is "sort of" a parallel ILU). 

   Barry

> 
> You advice is highly appreciated. 
> 
> -- 
> Najeeb Ahmad
> 
> Research and Teaching Assistant
> PARallel and MultiCORE Computing Laboratory (ParCoreLab) 
> Computer Science and Engineering
> Koç University, Istanbul, Turkey
>