Solving sparse underdetermined linear systems

According to qr_mumps / qr_mumps · GitLab, StarPU is used for parallelization. I’m pretty sure that there is no MPI parallelization and setting OMP_NUM_THREADS=1 still gives 0.2 sec.

To me, it seems plausible: Choosing an appropriate algorithm gives normally the larger gain in comparison to parallelization and for sub-second runtimes, overhead and serial sections often prevent any parallel speedup.


Thanks @MarDie! I was also able to compile it as you say (without parallelization) and it does seem for this size problem, it’s good enough.