Hi, I'm solving Stokes problem in a coupled way with Vanka smoothers and MG and I need to choose a solver for the coarse grid correction. I've tried with an iterative solver too but it works only fairly on regular grids with few processes and otherwise performs very poorly with communication dominated calculations.
I'd like to know if the tufo-fischer direct solver is suitable to solve saddle problems. The matrix is full rank. Thank you, Domenico
