MATLAB: Mpiprofile viewer crashes unexpectedly

MATLABParallel Computing Toolbox

The following minimal code

parpool
spmd
    mpiprofile on
    mpiprofile viewer
end
disp('there is a db point set at this line')

displays the following :

Lab 1:

Sending pmode lab2client to the MATLAB client for asynchronous evaluation. "

with this error message coming next :

Undefined function or variable 'MPI_PROF_VECTOR'.

Any clue ?

I suspect the debug breakpoint is interfering with the data transfer from the spmd block back to the client.

I suppose the only workaround is: don't put a breakpoint there!

Starting in R2020a, you can invoke mpiprofile directly from the client, so you can do this instead:

parpool
mpiprofile on
spmd
    % do stuff
end
mpiprofile viewer

I believe this approach should not be affected by the presence of breakpoints.

One way I figured to do something similar is the following.

I am assuming you are using "pmode" because as far as my understanding goes, you need to run on "pmode" to run mpiprofile.

So this is how it goes.

1. Save the mpiprofile info inside each worker(or it is often called lab from my understanding).

mpiprofile mpistruct;

2. Then you transfer to the client using the following command

pmode lab2client mpistruct;

3. Then save the mpistruct into a .mat file

save('mpistruct');

When you are trying to view the mpiprofile result:

1. Load the mpi file

load('mpistruct.mat');

2. Run mpiprofile viewer

mpiprofile('viewer', mpistruct);

This should pop up the browser.

Note. Above code was tested with 2015b.

Support for using "mpiprofile" on "parfor" loops was added in MATLAB R2020a:

In prior releases, "mpiprofile" only works on communicating jobs:

"The parallel profiler works on communicating jobs, including inside pmode. It does not work on parfor-loops."