El 23/11/2011, a las 16:25, Barry Smith escribi?: > > On Nov 23, 2011, at 7:18 AM, Jed Brown wrote: > >> On Wed, Nov 23, 2011 at 05:43, Dominik Szczerba <dominik at itis.ethz.ch> >> wrote: >> In my procedure considerable time is spent to partition the domain. >> When using MUMPS as a solver for my matrix I see the message: >> >> "Ordering based on METIS" >> >> This is an ordering to reduce fill in factorization, not to to partition the >> domain. Last I heard, symbolic factorization was done in serial, which >> explains why you find it taking a lot of time. The right hand side and >> solution vectors are also passed on rank 0, which presents another >> inefficiency/imbalance and memory bottleneck. Talk to the MUMPS developers >> or use a different package if you don't like these properties. > > Mumps does now have an option of parallel ordering. > > Run with -help and look at the options like > > -mat_mumps_icntl_28","ICNTL(28): use 1 for sequential analysis and ictnl(7) > ordering, or 2 for parallel analysis and ictnl(29) ordering > > -mat_mumps_icntl_29","ICNTL(29): parallel ordering 1 = ptscotch 2 = parmetis > > > I apologize that the options are organized in such a silly way but that is > how MUMPS is organized. > > Barry >
I have a question related to this. We tried today (with petsc-dev) -mat_mumps_icntl_28 2 -mat_mumps_icntl_29 2 and it works, but -mat_mumps_icntl_28 2 -mat_mumps_icntl_29 1 gives an error of MUMPS complaining that PTScotch was not enabled. Should the combination MUMPS+PTScotch work in petsc-dev? We did --download-mumps --download-ptscotch --download-parmetis Jose
