[petsc-users] Pipelined solvers PIPECG etc fail

[Håkon Strandenes]

I just tested KSP ex2, and this error happened if I ran the code with 
"-ksp_type pipecg" or "-ksp_type pipecr", just as it did with my code. I 
used an unmodified version of KSP ex2, so I guess I don't have to send 
you my code... The error message was also the same.

As far as I can see from the error message, this error has something to 
do with the convergence criterion... There must be some ways to stop the 
iteration process other than running a fixed number of iterations?

Håkon


On 20. nov. 2014 14:17, Matthew Knepley wrote:
> On Thu, Nov 20, 2014 at 4:05 AM, Håkon Strandenes <haakon at hakostra.net
> <mailto:haakon at hakostra.net>> wrote:
>
>     Hi,
>
>     First: thanks to the list and Barry for solving my previous problem
>     on loading vectors from HDF5 files. It works great!
>
>     Now a second problem: I want to try the pipelined KSP solvers,
>     PIPECG in particular. However, my program fails on the first
>     KSPSolve() with the message below. The same happens if I try PIPECR.
>
>
> These are very new, so there could be bugs lurking. It would help our
> testing if this is
> reproducuble on a standard example. Does this happen if you try to solve
> KSP ex2
> or SNES ex5 with PIPECG?
>
>     Thanks,
>
>       Matt
>
>     I have tried this on three MPI implementations, on and two of them
>     fully support MPI 3 (I have read
>     http://www.mcs.anl.gov/petsc/__documentation/faq.html#__pipelined
>     <http://www.mcs.anl.gov/petsc/documentation/faq.html#pipelined>). I
>     am using latest PETSc from Git repo.
>
>     I have tried to turn off the preconditioner without any effect.
>
>     The equation system is the result of a finite-volume discretization
>     of a Poisson-like equation if that helps anything. A normal CG
>     solver works like a charm, converging fast and effective.
>
>     Are there any tricks to get this working? Anything special I have to
>     set and/or define to get this solver running?
>
>     Thanks in advance.
>
>     Best regards,
>     Håkon Strandenes
>
>
>     Error message:
>
>     [0]PETSC ERROR: --------------------- Error Message
>     ------------------------------__------------------------------__--
>     [0]PETSC ERROR: Object is in wrong state
>     [0]PETSC ERROR: Use KSPConvergedSkip() with KSPNormType of KSP_NORM_NONE
>     [0]PETSC ERROR: See
>     http://www.mcs.anl.gov/petsc/__documentation/faq.html
>     <http://www.mcs.anl.gov/petsc/documentation/faq.html> for trouble
>     shooting.
>     [0]PETSC ERROR: Petsc Release Version 3.5.2, unknown
>     [0]PETSC ERROR: madns on a arch-linux2-c-debug named hakostra-kontor
>     by hakostra Thu Nov 20 11:04:28 2014
>     [0]PETSC ERROR: Configure options
>     --prefix=/opt/petsc/git-debug/__install --with-shared-libraries
>     --download-hypre --with-64-bit-indices --with-hdf5
>     --with-hdf5-dir=/opt/HDF5/1.8.__13/install --with-debugging
>     --with-debugger=gdb
>     [0]PETSC ERROR: #1 KSPConvergedDefault() line 710 in
>     /opt/petsc/git-debug/source/__src/ksp/ksp/interface/__iterativ.c
>     [0]PETSC ERROR: #2 KSPSolve_PIPECG() line 99 in
>     /opt/petsc/git-debug/source/__src/ksp/ksp/impls/cg/pipecg/__pipecg.c
>     [0]PETSC ERROR: #3 KSPSolve() line 459 in
>     /opt/petsc/git-debug/source/__src/ksp/ksp/interface/itfunc.c
>     [0]PETSC ERROR: #4 findPressure() line 53 in
>     /opt/MaDNS/source/src/FVM2.cpp
>
>
>
>
> --
> 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