Hey Bruno
In the 'diffusion2dc-mpi-nonblocking.c' code, I see that for all ranks you populate all surrounding boundary points with the fixed temperature distribution - even on the sides that would be on the interior edges of the domain decomposition. Is this done because the communication calls below will overwrite the appropriate arrays on the correct sides? i.e. if its an interior edge, the fixed values will be overwritten with the current value of the neighbour, while for exterior edges, the Isend and Irecv calls will attempt to communicate with MPI_PROC_NULL and not overwrite the fixed distribution?
Thanks,
Clint