Hello Pierre,
I just tested it, it's working just fine !
I thought i could have problems using mumps, as i rapidly read your
article, and that i may be using MatMatSolve, but no, it's working.
I have correct results.
This interface for multi-RHS is indeed very handy.
One question : I used KSPSetMatSolveBlockSize(ksp,1);
I don't know what it is doing, i saw it on your example.
Is it mandatory ?
Thanks a lot,
Yann
Le 9/17/2020 à 6:08 PM, Pierre Jolivet a écrit :
Hello Yann,
This is probably not fully answering your question, but the proper way
to solve a system with N RHS is _not_ to use KSPSolve(), but instead
KSPMatSolve(), cf.
https://www.mcs.anl.gov/petsc/petsc-dev/docs/manualpages/KSP/KSPMatSolve.html.
If you are tracking master (from the GitLab repository), it’s available
out of the box. If you are using the release tarballs, it will be
available in 3.14.0 scheduled to be released in a couple of days.
If you want to know more about the current status of block solvers in
PETSc, please feel free to have a look at this preprint:
http://jolivet.perso.enseeiht.fr/article.pdf
If you are using a specific PC which is not “multi-RHS ready”, see the
list at the top of page 5, please let me know and I’ll tell you how easy
to support it.
Thanks,
Pierre
