[petsc-users] subdomain solver options

[Matthew Knepley]

On Tue, Aug 26, 2025 at 12:45 PM Anton Popov <popov at uni-mainz.de> wrote:

> There is an important addition, I use asm and bjacobi as smoothers on
> multigrid levels.
>
> So I probably need to set the options with -mg_levels_sub_, or
> -mg_levels_3_sub_(if they are different on different levels), instead of
> just -sub_.
>
> Correct?
>

Yes, and as Mark says, you can see the prefix if you View the solver.

  Thanks,

     Matt


> Anton
>
>
>
> On 26.08.25 18:20, Anton Popov wrote:
> > Hi all,
> >
> > I have a strange behavior setting the solver options for asm and
> > bjacobi blocks.
> >
> > Irrespective of what I set with -sub_ksp_ -sub_pc_ it just selects the
> > default preonly and ilu options.
> >
> > This behavior does not change no matter how many local blocks per cpu
> > I try to use, for example with the default one block/cpu it does not
> > work as well.
> >
> > Is there anything wrong?
> >
> > Best,
> >
> > Anton
> >
>


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