On 04/01/2015 01:31 PM, Barry Smith wrote:
Dominic,
I have turned the optimization on to skip the unneeded copy with the
DMLocalToLocal in the branches barry/optimize-dmlocaltolocal_da and next. It
passes all the PETSc tests; let me know if you see any problems.
Great, thanks very much. I'll give it a shot.
Cheers,
Dominic
Barry
On Mar 31, 2015, at 12:21 PM, Dominic Meiser <[email protected]> wrote:
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.
Barry
On 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
--
Dominic Meiser
Tech-X Corporation
5621 Arapahoe Avenue
Boulder, CO 80303
USA
Telephone: 303-996-2036
Fax: 303-448-7756
www.txcorp.com
