David Wells

Yes, this would be good to have!

The discussion in August is slowly coming back to mind. You're both right of course. We already ban using multiple threads with PETSc so this won't be an issue. I'll...

> What @Rombur did for Trilinos is creating new vectors in a different namespace. I think that is what is appropriate here too. We can do three things at once,...

I think that PETSc still keeps track of things at a global level, so one cannot create PETSc objects simultaneously across multiple threads without getting a race condition. I'll look...

I agree. Creating multiple subscriptions is probably not thread-safe. PETSc also supports compilation in a 'thread-safe' mode which I think prevents these race conditions.

I'm curious - what do you want to use the mapping's support points for? If we introduce this here we should do the same for `MappingFE` (which, by assertion check,...

@jppelteret this was fixed by #12278, right?

One possibility would be to settle on a single sparse eigenvalue/eigenvector package: we have our own stuff (which should be deprecated), arpack, and slepc.

@bangerth do we have a plan for fixing this by 9.1?

Was this completely fixed by #11414?