> Yes, this is what I did.
> But I have a function that sets up the preconditioner by taking a KSP
> as an argument. Depending on the problem being solved, it can be a
> single KSP or a sub-KSP coming from a field split (which if there are
> lagrange multipliers, can be further split again). So
Barry Smith writes:
>> 1. Is there a way to set the mg_levels_pc_type via an API call?
>> 2. Are there any changes in efficiency expected with this new PC?
>
> This was changed mainly because PCSOR is not effective (currently in PETSc)
> for GPUs. For CPUs
> it will definitely be problem
> On May 20, 2022, at 2:39 PM, Jeremy Theler wrote:
>
> The default smoothing PC changed from sor to jacobi in 3.17.
Note that this is only for GAMG, it is not for geometric multigrid (using
PCMG directly).
> The
> Changelog says the old behavior can be recovered by using
>
The default smoothing PC changed from sor to jacobi in 3.17. The
Changelog says the old behavior can be recovered by using
-mg_levels_pc_type sor.
1. Is there a way to set the mg_levels_pc_type via an API call?
2. Are there any changes in efficiency expected with this new PC?
Regards
--
jeremy
