[petsc-users] 2 levels of parallelism for ASM

[DUFAUD THOMAS]

Hi,
I noticed that the local solution of an ASM preconditioner is performed on a single processor per domain, usually setting a KSP PREONLY to perform an ILU factorization.
I would like to perform those local solution with a krylov method (GMRES) among a set of processors. 

Is it possible, for an ASM preconditioner, to set a subgroup of processors per domain and then define parallel sub-solver over a sub-communicator?

If it is the case how can I manage operation such as MatIncreaseOverlap?
If it is not the case, does it exist a way to do that in PETSc?

Thanks, 

Thomas