Draft: Add host weights to METIS partitioning

See #856 first implementation of the basics. Largely untested!

examples/parameter_example.yml

@@ -255,11 +255,16 @@ DomainDecomposition:
                               # using CPU time trigger
   usemetis:         0         # Use serial METIS when ParMETIS is also available.
   adaptive:         1         # Use adaptive repartition when ParMETIS is available, otherwise simple refinement.
+  permute:          1         # Use a permutation of the solution if that reduces particle movement.
   itr:              100       # When adaptive defines the ratio of inter node communication time to data redistribution time, in the range 0.00001 to 10000000.0.
                               # Lower values give less data movement during redistributions, at the cost of global balance which may require more communication.
   use_fixed_costs:  0         # If 1 then use any compiled in fixed costs for
                               # task weights in first repartition, if 0 only use task timings, if > 1 only use
                               # fixed costs, unless none are available.
+  host_weights_file: none     # (Optional) A text file with MPI_processor_name vertex_weight columns.
+                              # Used when running on cluster with heterogeneous compute nodes,
+                              # the weight is the extra size of the vertex, so for instance reflects
+                              # the node relative speeds, larger is faster.
 
 # Structure finding options (requires velociraptor)
 StructureFinding: