Michel,
This is a very annoying feature that has been fixed in master
http://www.mcs.anl.gov/petsc/developers/index.html I would like to have
changed it in maint but Jed would have a shit-fit :-) since it changes behavior.
Barry
> On Jul 16, 2015, at 4:53 PM, Michele Rosso <[email protected]> wrote:
>
> Hi,
>
> I am performing a series of solves inside a loop. The matrix for each solve
> changes but not enough to justify a rebuilt of the PC at each solve.
> Therefore I am using KSPSetReusePreconditioner to avoid rebuilding unless
> necessary. The solver is CG + MG with a custom PC at the coarse level.
> If KSP is not updated each time, everything works as it is supposed to.
> When instead I allow the default PETSc behavior, i.e. updating PC every time
> the matrix changes, the coarse level KSP , initially set to PREONLY, is
> changed into GMRES
> after the first solve. I am not sure where the problem lies (my PC or PETSc),
> so I would like to have your opinion on this.
> I attached the ksp_view for the 2 successive solve and the options stack.
>
> Thanks for your help,
> Michel
>
>
>
> <ksp_view.txt><petsc_options.txt>
