Halos : Différence entre versions

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== Warning: Quite technical stuff here!!! ==
 
== Warning: Quite technical stuff here!!! ==
  
In the dynamics, the MPI/OpenMP assigned  domains to a each core can be hard to keep up with... especially as it also depends on the grid (scalar, U, V) a given variable is
+
In the dynamics, the MPI assigned  domains to a each core can be hard to track of... especially as it also depends on the grid (scalar, U, V) a given variable is
  
 
Some nomenclature:
 
Some nomenclature:
 +
* jjb_u, jje_u => "latitudinal indexes", for a variable on  the (iip1,jjb_u:jje_u) horizontal grid U grid
 +
* jjb_v, jje_v => "latitudinal indexes", for a variable on  the (iip1,jjb_v:jje_v) horizontal grid V grid
 
* ijb_u => "ij": linear index (horizontal grid) "b": begin (i.e. index at which the domain starts) "_u": U grid
 
* ijb_u => "ij": linear index (horizontal grid) "b": begin (i.e. index at which the domain starts) "_u": U grid
 
* ije_u => "ij": linear index (horizontal grid) "e": end (i.e. index at which the domain ends) "_u": U grid
 
* ije_u => "ij": linear index (horizontal grid) "e": end (i.e. index at which the domain ends) "_u": U grid
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[[Category:Parallel]]
 
[[Category:Parallel]]
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[[Category:ExpertDev]]

Version actuelle en date du 17 novembre 2021 à 14:51

Warning: Quite technical stuff here!!!

In the dynamics, the MPI assigned domains to a each core can be hard to track of... especially as it also depends on the grid (scalar, U, V) a given variable is

Some nomenclature:

  • jjb_u, jje_u => "latitudinal indexes", for a variable on the (iip1,jjb_u:jje_u) horizontal grid U grid
  • jjb_v, jje_v => "latitudinal indexes", for a variable on the (iip1,jjb_v:jje_v) horizontal grid V grid
  • ijb_u => "ij": linear index (horizontal grid) "b": begin (i.e. index at which the domain starts) "_u": U grid
  • ije_u => "ij": linear index (horizontal grid) "e": end (i.e. index at which the domain ends) "_u": U grid
  • ijb_v => "ij": linear index (horizontal grid) "b": begin (i.e. index at which the domain starts) "_v": V grid
  • ije_v => "ij": linear index (horizontal grid) "e": end (i.e. index at which the domain ends) "_v": V grid

These boundaries include halos (i.e. neighboring values at the junction with adjacent domains), whereas the ij_begin and ij_end don't (see parallel_lmdz.F90).

Scalars, which are not technically on the U grid, but on a grid with identical dimensions, are indexed as if they were on the U grid.

The Register_SwapField routines copy the inner boundary values of a domain to propagate them to the other domains and fill their respective halos.

04/11/2021