On Jan 27, 2012, at 12:18 PM, Jed Brown wrote: > On Fri, Jan 27, 2012 at 11:16, Anton Popov <popov at uni-mainz.de> wrote: > Does PETSc support repartitioning of coarse grid operators onto a smaller > subset of processors during coarsening? Or the coarsest grid must be > represented on the same amount of processors as the finest? It becomes a > problem when a lot of processors are employed (say 4096 or more). If it is > supported, how can I use it? > > PCGAMG does this automatically. There are some technical challenges to doing > this with geometric multigrid, but we are thinking about how to do it best.
GAMG does not repartition by default anymore -- it is very expensive. GAMG does now do simple process aggregation on coarser grids if repartitioning is not specified. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120127/b7254221/attachment.htm>
