OpenMP and MPI hybrid program

Question

I have a machine with 8 processors. I want to alternate using OpenMP and MPI on my code like this:

OpenMP phase:

• ranks 1-7 wait on a M

Answer 1

Thanks all for the comments and answers. You are all right. It's all about the "PIN" option.

To solve my problem, I just had to:

I_MPI_WAIT_MODE=1

I_MPI_PIN_DOMAIN=omp

Simple as that. Now all processors are available to all ranks.

The option

I_MPI_DEBUG=4

shows which processors each rank gets.