METIS segfaults during partitioning of large meshes

[kubagalecki]

Since for the time being mesh initialization, conversion, and partitioning takes place on a single MPI rank, it follows that there is a hard limit on the mesh size. However, it seems that even before that ceiling is reached, METIS crashes during mesh partitioning. The reason is possibly signed integer overflow.

Possible workarounds:

• build METIS with 64 bit index type
• reduce mesh size (that's not really much of a solution)

Mesh that partitioning failed on: 20x20x20 cube, 6th order (~1.77mln nodes)

Stacktrace:

[hyp-02:30623] *** Process received signal ***
[hyp-02:30623] Signal: Segmentation fault (11)
[hyp-02:30623] Signal code: Address not mapped (1)
[hyp-02:30623] Failing at address: 0xfffffffe0b34fc88
[hyp-02:30623] [ 0] /lib64/libpthread.so.0(+0xf5e0)[0x7f07818ca5e0]
[hyp-02:30623] [ 1] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(libmetis__CreateCoarseGraphNoMask+0x1ee)[0x7f0782b8b1de]
[hyp-02:30623] [ 2] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(libmetis__Match_SHEM+0x42c)[0x7f0782b8c67c]
[hyp-02:30623] [ 3] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(libmetis__CoarsenGraph+0x1bd)[0x7f0782b8cb6d]
[hyp-02:30623] [ 4] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(libmetis__MultilevelBisect+0xd6)[0x7f0782bab5a6]
[hyp-02:30623] [ 5] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(libmetis__MlevelRecursiveBisection+0xec)[0x7f0782babc5c]
[hyp-02:30623] [ 6] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(libmetis__MlevelRecursiveBisection+0x340)[0x7f0782babeb0]
[hyp-02:30623] [ 7] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(METIS_PartGraphRecursive+0x18e)[0x7f0782bac04e]
[hyp-02:30623] [ 8] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(libmetis__InitKWayPartitioning+0x15a)[0x7f0782b980ca]
[hyp-02:30623] [ 9] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(libmetis__MlevelKWayPartitioning+0x115)[0x7f0782b98205]
[hyp-02:30623] [10] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(METIS_PartGraphKway+0x1f4)[0x7f0782b984e4]
[hyp-02:30623] [11] /home/jgalecki/spack/var/spack/environments/l3ster-dependencies/.spack-env/view/lib/libmetis.so(METIS_PartMeshNodal+0x2af)[0x7f0782ba2dff]
[hyp-02:30623] [12] /mnt/beegfs/jgalecki/L3STER/bench/benchmarks/Diffusion3DBenchmark[0x478040]
[hyp-02:30623] [13] /mnt/beegfs/jgalecki/L3STER/bench/benchmarks/Diffusion3DBenchmark[0x4ee503]
[hyp-02:30623] [14] /mnt/beegfs/jgalecki/L3STER/bench/benchmarks/Diffusion3DBenchmark[0x4f05ca]
[hyp-02:30623] [15] /mnt/beegfs/jgalecki/L3STER/bench/benchmarks/Diffusion3DBenchmark[0x420320]
[hyp-02:30623] [16] /lib64/libc.so.6(__libc_start_main+0xf5)[0x7f0781519c05]
[hyp-02:30623] [17] /mnt/beegfs/jgalecki/L3STER/bench/benchmarks/Diffusion3DBenchmark[0x422d24]
[hyp-02:30623] *** End of error message ***

Blocked by: #26