[gmx-developers] Domain decomposition and consistency of state and state_global

[Vedran Miletić]

Hello,

I'm developing the conditional stop feature (proposal at [1], a somewhat
working (but not yet mergeable) code dump at [2]; it's using 2016, but
will be rebased to 2018 and master when done). Non-DD code is rather
easy to get up and running, but I'm struggling with understanding how am
I supposed to use state and state_global with DD.

I figured out how ga2la_get() is intended to be used, but the local atom
coordinates I get (relevant part of the log file is in [3]) are
consistent with global atom coordinates in 0 (modulo 8x8x8 box PBC,
which is taken into account when computing distances), but not in step 1000.

I assume that new coordinates have not been communicated yet and that
I'm placing the code somewhere wrongly. Aside from the placement in [4],
I tried placing it in both places after dd_collect_state() in the main
while loop, but it did not help.

Ideas are welcome.

Thanks,
Vedran

[1] https://redmine.gromacs.org/issues/2224
[2]
https://github.com/hits-mbm/gromacs-developments/tree/conditional-stop-release-2016
[3]
https://vedran.miletic.net/projects/gromacs/conditional-stop-gmx-debug.log
[4]
https://github.com/HITS-MBM/gromacs-developments/blob/conditional-stop-release-2016/src/programs/mdrun/md.cpp#L1276

-- 
Vedran Miletić
vedran.miletic.net