How to use mpirun to run an code which is already developed in multiprocessing style

[dokken]

First of all, using mshr to generate meshes inside a parallel (mpirun) code is not recommended.

To get anywhere near what you would like to do, i would split the mpi communicator in 2, as shown in

A general parallel process

You want to extract my_alpha based on the color, rather than the rank, otherwise processors in the same group after split end up having different values of alpha. Modified code from dolfin import * # set MPI communicator comm = MPI.comm_world size = comm.Get_size() rank = comm.Get_rank() # split comm_world in two groups group_rank = rank // 2 color = rank % 2 new_comm = comm.Split(color, group_rank) # new_comm = comm.Split(color=color) new_rank = new_comm.Get_rank() new_size = new_comm.Get_siz…

But then you should Also create your mesh ahead of time, and read it in with XDMFFile for efficiency