Matthew Knepley <knepley at gmail.com> writes: > On Tue, May 7, 2013 at 10:53 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote: > >> This thread is complaining about DMDA costing multiple vectors worth >> of memory. >> >> https://groups.google.com/d/msg/claw-dev/JwIjL5e48No/NOizc6i88gkJ >> >> We currently set a lot of stuff up eagerly so that it can be accessed >> using non-collective accessors. When a Krylov method is used or a >> matrix is assembled, that stuff is in the noise, but for explicit >> methods, it can be the limiting factor for problem size. Should we >> do something about this? >> > > I would at least like to know what it is, and how the interface would > have to change. This can't be all scatter memory.
At the very least, it's global-to-local scatter, local-to-local scatter, and local-to-global mapping (scalar and block).
