MKL_pardiso weird behaviour with large matrices

Hello, everybody.

Still trying to solve very large systems of sparse equations with `mkl pardiso`, single node, multiple thread version. The solver is behaving really well for small systems, but not so much for larger equations. In our case, scalability is essential.

With a large enough system of linear equations (79999 x 79999, 100528321 non-zeros), the sovler returns a vectors of `-nan`s, without reporting any errors. The expected result is provided (`expected-result.txt`).

The example code is provided below. The data is linked to here: https://www.dropbox.com/s/jcvieffrkb7ivag/data.tar.gz?dl=0. It is a `tar.gz` archive with the binary matrix representation, read by the code provided below.

There is an additional strange behaviour of the solver, where the `allocation of internal data structures` in the factorization phase is dominating the runtime. It is taking one user thread (100% user time), and take the majority of the executable's time. This behaviour is similar to that described here: https://software.intel.com/en-us/forums/intel-math-kernel-library/topic/.... I believe the core of the issue is within `parMETIS`, not `pardiso`.

The code is linked against MKL `11.2.3`, release `composer_xe_2015.3.187`.

Thank you for your assistance. I would be happy to provide additional details.