Hi 

I am working on hybrid MPI -OpenMp code and face with a problem. I can not run the code as the way that I want.

I can run pure mpi code and also pure openmp code, but not hybrid one.

I used "export OMP_NUM_THREADS=6" and then "mpirun -np 4 ./hybrid.exe > output.txt"

It run but I noticed that It used only virtual threads of  CPUs not physical threads.

I have both OpenMpi and Mpich  on my computer.

My problem is I want to use mpi for communication between nodes and sockets and Openmp for cores which are inside of sockets and nodes, I do not know how to pin cpu to each other in each socket and nodes. I could find some material on internet such as 

https://aciref.org/how-to-gain-hybrid-mpi-openmp-code-performance-without-changing-a-line-of-code-a-k-a-dealing-with-task-affinity/

But it did not work, I think I need a PBS file to assign those commands on my grid with qsub command.

If you need more information please let me know. 

I am looking forward to hearing from you,

Best regards.

Pasha