The old version incorrectly relied on sorted index sets and may have had other logic errors. This one is memory-scalable and does not build intermediate data structures (only a couple int arrays of size rmap->n and cmap->n). I think that similar code could be used for MatGetSubMatrix_MPIAIJ (these routines could share) to eliminate the rather heavy intermediate matrix and avoid the nonscalable ISAllGather().
https://bitbucket.org/petsc/petsc-dev/changeset/07d68b96ea817de2774690b3f0b106c7ceaff281 https://bitbucket.org/petsc/petsc-dev/changeset/2c0dc68cfb82d9005df9927b58bd8b7f84e0024e (doc fix) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20121020/5295d043/attachment.html>
