On Thu, 15 Apr 2010, Roy Stogner wrote: > On Thu, 15 Apr 2010, Derek Gaston wrote: > >> On Apr 15, 2010, at 9:57 AM, Roy Stogner wrote: >> >>> So the problem is OS, compiler, and MPI implementation independent. >>> Still a slim chance it's PETSc (I've only reproduced it on 3.0.0, >>> couldn't get it to crop up with a brief test using 3.1) but I'd bet >>> it's us. >> >> We still use Petsc 2.3.3 around here... and haven't run into this >> problem (and we do use Constant Monomials and adaptivity quite a >> bit). That's just one data point... but it could be some >> interaction with libMesh and Petsc 3.0. > > It might be triggered by PETSc in some subtle way, but I'm certain now > it's not being caused by PETSc - we've got a corrupt entry being > generated at the end of the send_list. > > Still need to figure out how. If you haven't triggered it, and I > can't trigger it with any CG work, then my best guess is that I typoed > Lorenzo's latest DG send_list patch when integrating that recently.
My best guess was *way* off. There are a few problem fixes that I'll be committing in a minute, but the real killer looks like it's in the projection send_list construction used by System::project_vector. We were getting invalid_id added to the list during adaptive coarsening of discontinuous elements, and PETSc naturally can react badly when told to scatter index -1. The same bug could affect adaptive coarsening of high order non-Lagrange continous elements, but I suspect nobody would have noticed it, since that manifestation would have been to add a little extra projection error to elements where you'd just decided to coarsen them anyway. --- Roy ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
