[petsc-users] Reusing A00 block with Schur complement

[Barry Smith]

It is suppose to not rebuild the preconditioner for the A00 block if the matrix does not change; and automatically rebuild if it does change.

> On Jul 20, 2022, at 4:14 PM, Mike Welland <mike at mikewelland.com> wrote:
> 
> My A00 block in an SNES solve with a Schur complement preconditioner is constant, and I'd like to exploit this for computational speedup. I'm running PETSc through a FEM package (Firedrake) so only have ready access to the options database (I believe that to be the command line arguments)
> 
> Is this automatically recognized or is there an option I can set?
> Thanks