Update partitioning code to 64 bit (was: Seg fault partitioning large mesh)
I am getting segmentation faults in gmsh 4.4.1 (and other versions) when I try to partition a mesh with Info : 166593827 nodes Info : 1030066524 elements
The seg fault happens when I use metis and when I use the Plugin SimplePartition
There are 2 steps in porting the partitioning code to 64 bits :
modify the build system so that we build METIS with support for 64 bit indices when appropriate ; we should probably enable this by default on all 64 bit builds - at least on Unix. That's the easy part.
modify all the functions and datastructures in in Mesh/meshPartition.cpp to use the correct type. Internally Gmsh has been modified to use size_t tags for nodes and elements, but in the partitioning code we should probably use the METIS-provided typedef/#define to minimize the chances of introducing mistakes. This is the more complicated, time-consuming and error-prone part ;-)