[petsc-dev] Petsc "make test" have more failures for --with-openmp=1

[Matthew Knepley]

On Fri, Mar 19, 2021 at 7:30 AM Lawrence Mitchell <wence at gmx.li> wrote:

> > On 19 Mar 2021, at 03:51, Jed Brown <jed at jedbrown.org> wrote:
> >
> > It's a notable weakness of DMPlex that it does not apply such an
> ordering of dofs and I've complained to Matt about it many times over the
> years, but any blame rests solely with me for not carving out time to
> implement it here.
>
> I think there is a way to do this with plex (at least we do it), like so:
>
> DMPlexGetOrdering(dm, MATORDERINGRCM, NULL, &isperm);
>
> you might need to then invert this ordering.
>
> Now when you make a section you either say
>
> PetscSectionSetPermutation(section, isperm);
>

You can do that if you only want to permute the dofs, but usually I want to
reorder everything so that any Section comes out right

  DMPlexPermute()

  Thanks,

     Matt


> before PetscSectionSetup(section);
>
> or, if you're using DMPlexCreateSection, pass in the isperm
>
> This gives RCM-based ordering for the dof numbering of the section.
>
> Cheers,
>
> Lawrence



-- 
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

https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20210319/84e9e4a4/attachment.html>