[MITgcm-support] Question: boundary exchange, hrcube condfiguration

[Michael Schroeter]

Hi,

as Martin already reported in an earlier posting
(http://forge.csail.mit.edu/pipermail/mitgcm-support/2007-March/004719.html)
we have some unexpected scaling behaviour on a IBM p690
(cubed sphere configuration, 16 passive tracers).

We found out that the boundary exchange of the ptracers data seems to be
responsible for the slow down of the code. Now we have some ideas for
code optimazation.

However, there is one thing in the current code I do not unterstand.
In "exch2_3d_rl.F" the subroutine "EXCH2_RL1_CUBE" is called two times
with exactly the same values for the argument list parameters
(even if the cpp option "W2_FILL_NULL_REGIONS" is undefined).
Can anybody explain that to me?

Thanks in advance.

Regards
Michael

-- 
Dr. Michael Schroeter                          Phone: +49(471)4831-2084
Email: Michael.Schroeter at awi.de                Fax:   +49(471)4831-1149
Alfred-Wegener-Institute for Polar- and Marine Research
Am Handelshafen 12, D-27570 Bremerhaven                      www.awi.de