Great, thanks very much. Cheers, Dominic On 03/31/2015 10:24 AM, Barry Smith wrote:
Dominic,DMLocalToLocal is the intended usage. There is code inside the VecScatter to detect unneeded copies, which would result in only touching the ghost cells, but for some reason that is not currently turned on, I'll take a look at fixing it in master. BarryOn Mar 31, 2015, at 10:12 AM, Dominic Meiser <[email protected]> wrote: Hi, I have a DMDA for a structured grid in a 3D FDTD calculation. What is the most efficient way to update the ghost regions after each time step? Currently I update a global vector and then I scatter to a local vector using DMGlobalToLocalBegin/End for the next time step. I also tried DMLocalToLocal with the same source and target vector and that appears to be slightly faster, perhaps due to better cache usage in the copy of the owned region. Ideally I would like to update just the ghost cells from the owned regions. Is there a good way to do that? Something similar to VecGhostUpdateBegin/End? Thanks, Dominic -- Dominic Meiser Tech-X Corporation 5621 Arapahoe Avenue Boulder, CO 80303 USA Telephone: 303-996-2036 Fax: 303-448-7756 www.txcorp.com
-- Dominic Meiser Tech-X Corporation 5621 Arapahoe Avenue Boulder, CO 80303 USA Telephone: 303-996-2036 Fax: 303-448-7756 www.txcorp.com
