[petsc-users] 2 levels of parallelism for ASM

[Raeth, Peter]

Hello Thomas.

Am only just now learning how to use PETSc. My particular concern is calculating the Kronecker Tensor Product. Running out of memory is the biggest roadblock, even though I think I have four times the required memory available and am destroying matrices as they are no longer needed.

Would like to lurk on your thread as a learning exercise. Do you want to start a thread on PETSc's users' group?


Best,

Peter.

Peter G. Raeth, Ph.D.
Senior Staff Scientist
Signal and Image Processing
High Performance Technologies, Inc
937-904-5147
praeth at hpti.com

________________________________________
From: petsc-users-bounces at mcs.anl.gov [petsc-users-bounces at mcs.anl.gov] on behalf of DUFAUD THOMAS [thomas.dufaud at univ-lyon1.fr]
Sent: Monday, January 24, 2011 9:09 AM
To: petsc-users at mcs.anl.gov
Subject: [petsc-users] 2 levels of parallelism for ASM

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