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Better describe machine topology

Context

The topology (distribution on MPI sub-domains) of the NEMO routine timing could reveal pattern that can only be explained by hardware performance variability. It looks interesting to know on which node each sub-domain is placed. Even though this could be displayed by the scheduler, performance analysis would be facilitated if this information could be accessible from the layout.nc file, at the same place than MPI rank distribution.

  • Modifications of versioned files: mppini.F90

Proposal

Add a 2D variable named "machine", with the number of the allocated node per sub-domain. Modifications are already proposed and tested on trunk version

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