On Thu, Jan 28, 2016 at 11:36 AM, Xiangdong <epsco...@gmail.com> wrote:
> What functions/tools can I use for dynamic migration in DMPlex framework? > In this paper, http://arxiv.org/abs/1506.06194, we explain how to use the DMPlexMigrate() function to redistribute data. In the future, its likely we will add a function that wraps it up with determination of the new partition at the same time. > Can you also name some external mesh management systems? Thanks. > I will note that if load balance in the solve is your only concern, PCTelescope can redistribute the DMDA solve. Thanks, Matt > > Xiangdong > > On Thu, Jan 28, 2016 at 12:21 PM, Barry Smith <bsm...@mcs.anl.gov> wrote: > >> >> > On Jan 28, 2016, at 11:11 AM, Xiangdong <epsco...@gmail.com> wrote: >> > >> > Yes, it can be either DMDA or DMPlex. For example, I have 1D DMDA with >> Nx=10 and np=2. At the beginning each processor owns 5 cells. After some >> simulation time, I found that repartition the 10 cells into 3 and 7 is >> better for load balancing. Is there an easy/efficient way to migrate data >> from one partition to another partition? I am wondering whether there are >> some functions or libraries help me manage this redistribution. >> >> For DMDA we don't provide tools for doing this, nor do we expect to. >> For this type of need for dynamic migration we recommend using DMPlex or >> some external mesh management system. >> >> Barry >> >> > >> > Thanks. >> > Xiangdong >> > >> > On Thu, Jan 28, 2016 at 12:20 AM, Jed Brown <j...@jedbrown.org> wrote: >> > Xiangdong <epsco...@gmail.com> writes: >> > >> > > I have a question on dynamic load balance in petsc. I started running >> a >> > > simulation with one partition. As the simulation goes on, that >> partition >> > > may lead to load imbalance since it is a non-steady problem. If it is >> worth >> > > to perform the load balance, is there an easy way to re-partition the >> mesh >> > > and continue the simulation? >> > >> > Are you using a PETSc DM? What "mesh"? If you own it, then >> > repartitioning it is entirely your business. >> > >> > In general, after adapting the mesh, you rebuild all algebraic data >> > structures. Solvers can be reset (SNESReset, etc.). >> > >> >> > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
