Learning by doing :: MPI -- Virtual Topologies In MPI, Part 2

This video is part of the new series called "Learning by doing :: MPI" which serves as an introductory course on MPI (Message Passing Interface). In this video we talked about virtual topologies in MPI! This topic corresponds to chapter 8 of the MPI standard v4.1. It is a lengthy chapter with a lot of information to digest. We followed the same pattern as for "Datatypes in MPI" by dividing a chapter into digestible ~25 mins long parts. In part 2 we continued our discussion with the first topology constructor for cartesian grids(MPI_Cart_create). We have seen two simple code examples for that. First example showing how MPI_Dims_create can be used to figure out the number of processes required for each dimension of the grid. The second example showed the scenario where number of processes required for the Cartesian grid is less than the actual processes in our MPI application which in turn some of the processes will end up having MPI_COMM_NULL. Finally, we talked about MPI_Graph_create which is a topology constructor for general graphs. In this constructor all the participating MPI processes must know about the whole structure of the graph which makes it not a reasonable choice because of scalability issues.

All the necessary info you need for MPI standard can be downloaded from here : https://www.mpi-forum.org/docs/mpi-4....

If you want to download MPICH, please visit here : https://www.mpich.org/downloads/
* The latest version at the time of this video is mpich-4.2.2

Hope you learned something from this video. If you have further questions don't hesitate to comment down below. Have fun!