On Tue, Dec 7, 2010 at 20:21, Ethan Coon <ecoon at lanl.gov> wrote: > 'd like a DA where there are ghost cells on every boundary, and some of > those ghost cells (but not all) are filled in with periodic values. >
It would be useful to people doing explicit stuff if there was a way to get ghost nodes in the local vector without implying periodic communication (and weird coordinate management). A related issue for purely explicit is to have a way to VecAXPY without needing to copy to and from a global vector. (TSSSP has low-memory schemes, paying for an extra vector or two is actually significant in that context, and (less significant) I'm certain I can cook up a realistic benchmark where the memcpy costs more than 10%.) I think I know how to implement this sharing transparently (more-or-less using VecNest) so we could make it non-default but be able to activate it at runtime. Jed -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20101207/ed2906a1/attachment.html>
