Thanks Barry,
We'll send the code to petsc-maint in a moment.
But we really don't want to bother you a lot.
Anton and Boris
On 6/28/12 8:55 PM, Barry Smith wrote:
> Anton,
>
> This came about because we are now being much more pedantic about the
> blocksizes of PETSc objects and not allowing them to be causally changed when
> they shouldn't be.
>
> You can resolve this problem by editing the file
> src/ksp/pc/impls/fieldsplit/fieldsplit.c locate the function
>
> #undef __FUNCT__
> #define __FUNCT__ "PCApply_FieldSplit"
> static PetscErrorCode PCApply_FieldSplit(PC pc,Vec x,Vec y)
> {
> PC_FieldSplit *jac = (PC_FieldSplit*)pc->data;
> PetscErrorCode ierr;
> PC_FieldSplitLink ilink = jac->head;
> PetscInt cnt,bs;
>
> PetscFunctionBegin;
>
> and add the two lines right here
>
> x->map->bs = jac->bs;
> y->map->bs = jac->bs;
>
>
> then run make cmake in that directory.
>
> To resolve this permanently we will need to figure out how to insure those
> inner vectors are created with the correct block size. Are you willing to
> share your code with petsc-maint at mcs.anl.gov so that we can reproduce the
> problem and fix it properly for the long run? (The problem is in PETSc not in
> your code).
>
> Barry
>
>
>
> On Jun 28, 2012, at 10:44 AM, Anton Popov wrote:
>
>> Dear petsc team,
>>
>> I'm trying to use fieldsplit preconditioner for the velocity block in the
>> Stokes system which is also preconditioned by
>> fieldsplit (kind of recursive).
>>
>> Running example 42 from src/ksp/ksp/examples/tutorials with petsc-3.2, as
>> follows:
>>
>> mpiexec -np 4 ./ex42 \
>> -stokes_ksp_type gcr \
>> -stokes_ksp_rtol 1.0e-6 \
>> -stokes_pc_type fieldsplit \
>> -stokes_pc_fieldsplit_type SCHUR \
>> -stokes_pc_fieldsplit_schur_factorization_type UPPER \
>> -stokes_fieldsplit_u_ksp_type fgmres \
>> -stokes_fieldsplit_u_ksp_rtol 1e-3 \
>> -stokes_fieldsplit_u_pc_type fieldsplit \
>> -stokes_fieldsplit_u_fieldsplit_ksp_type preonly \
>> -stokes_fieldsplit_u_fieldsplit_pc_type ml \
>> -stokes_fieldsplit_u_pc_fieldsplit_block_size 3 \
>> -stokes_fieldsplit_u_pc_fieldsplit_type ADDITIVE \
>> -stokes_fieldsplit_p_ksp_type preonly \
>> -stokes_fieldsplit_p_pc_type jacobi \
>> -stokes_ksp_monitor_blocks \
>> -mx 16 \
>> -model 3
>>
>> gives nicely looking output.
>>
>> But! Repeating the same exercise with petsc-3.3, like this (actually, there
>> is only one difference: factorization -> fact):
>>
>> mpiexec -np 4 ./ex42 \
>> -stokes_ksp_type gcr \
>> -stokes_ksp_rtol 1.0e-6 \
>> -stokes_pc_type fieldsplit \
>> -stokes_pc_fieldsplit_type SCHUR \
>> -stokes-pc_fieldsplit_schur_fact_type UPPER \
>> -stokes_fieldsplit_u_ksp_type fgmres \
>> -stokes_fieldsplit_u_ksp_rtol 1e-3 \
>> -stokes_fieldsplit_u_pc_type fieldsplit \
>> -stokes_fieldsplit_u_fieldsplit_ksp_type preonly \
>> -stokes_fieldsplit_u_fieldsplit_pc_type ml \
>> -stokes_fieldsplit_u_pc_fieldsplit_block_size 3 \
>> -stokes_fieldsplit_u_pc_fieldsplit_type ADDITIVE \
>> -stokes_fieldsplit_p_ksp_type preonly \
>> -stokes_fieldsplit_p_pc_type jacobi \
>> -stokes_ksp_monitor_blocks \
>> -mx 16 \
>> -model 3
>>
>> curses me hardly by claiming:
>>
>> [0]PETSC ERROR: --------------------- Error Message
>> ------------------------------------
>> [0]PETSC ERROR: Object is in wrong state!
>> [0]PETSC ERROR: Blocksize of x vector 1 does not match fieldsplit blocksize
>> 3!
>> [0]PETSC ERROR:
>> ------------------------------------------------------------------------
>> [0]PETSC ERROR: Petsc Release Version 3.3.0, Patch 0, Tue Jun 5 14:20:42
>> CDT 2012
>> [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: ./ex42 on a int32-deb named mac11-005.geo.uni-mainz.de by
>> anton Thu Jun 28 17:06:53 2012
>> [0]PETSC ERROR: Libraries linked from
>> /Users/anton/LIB/petsc-3.3-p0/int32-debug/lib
>> [0]PETSC ERROR: Configure run at Tue Jun 12 15:32:21 2012
>> [0]PETSC ERROR: Configure options PETSC_DIR=/Users/anton/LIB/petsc-3.3-p0
>> PETSC_ARCH=int32-debug --download-f-blas-lapack=1 --with-debugging=1
>> --COPTFLAGS="-g -O0" --FOPTFLAGS="-g -O0" --CXXOPTFLAGS="-g -O0"
>> --with-c++-support=1 --with-fortran=1 --with-fortran-kernels=1
>> --with-large-file-io=1 --with-mpi-compilers=1 --with-cc=mpicc
>> --with-cxx=mpicxx --with-fc=mpif90 --download-ml=1 --download-hypre=1
>> --download-blacs=1 --download-scalapack=1 --download-metis=1
>> --download-parmetis=1 --download-mumps=1 --download-superlu_dist=1
>> [0]PETSC ERROR:
>> ------------------------------------------------------------------------
>> [0]PETSC ERROR: PCApply_FieldSplit() line 726 in
>> /Users/anton/LIB/petsc-3.3-p0/src/ksp/pc/impls/fieldsplit/fieldsplit.c
>> [0]PETSC ERROR: PCApply() line 384 in
>> /Users/anton/LIB/petsc-3.3-p0/src/ksp/pc/interface/precon.c
>> [0]PETSC ERROR: KSPFGMRESCycle() line 169 in
>> /Users/anton/LIB/petsc-3.3-p0/src/ksp/ksp/impls/gmres/fgmres/fgmres.c
>> [0]PETSC ERROR: KSPSolve_FGMRES() line 294 in
>> /Users/anton/LIB/petsc-3.3-p0/src/ksp/ksp/impls/gmres/fgmres/fgmres.c
>> [0]PETSC ERROR: KSPSolve() line 446 in
>> /Users/anton/LIB/petsc-3.3-p0/src/ksp/ksp/interface/itfunc.c
>> [0]PETSC ERROR: PCApply_FieldSplit_Schur() line 693 in
>> /Users/anton/LIB/petsc-3.3-p0/src/ksp/pc/impls/fieldsplit/fieldsplit.c
>> [0]PETSC ERROR: PCApply() line 384 in
>> /Users/anton/LIB/petsc-3.3-p0/src/ksp/pc/interface/precon.c
>> [0]PETSC ERROR: KSPSolve_GCR_cycle() line 47 in
>> /Users/anton/LIB/petsc-3.3-p0/src/ksp/ksp/impls/gcr/gcr.c
>> [0]PETSC ERROR: KSPSolve_GCR() line 117 in
>> /Users/anton/LIB/petsc-3.3-p0/src/ksp/ksp/impls/gcr/gcr.c
>> [0]PETSC ERROR: KSPSolve() line 446 in
>> /Users/anton/LIB/petsc-3.3-p0/src/ksp/ksp/interface/itfunc.c
>> [0]PETSC ERROR: solve_stokes_3d_coupled() line 2045 in
>> src/ksp/ksp/examples/tutorials/ex42.c
>> [0]PETSC ERROR: main() line 2106 in src/ksp/ksp/examples/tutorials/ex42.c
>> application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0
>>
>> Similar error appeared in our code after upgrading to petsc-3.3, and we're
>> using similar functionality and options as I posted above.
>>
>> Please explain this issue. An advice how to get rid of the error is also
>> appreciated.
>>
>> Thanks a lot
>>
>> Anton
