Error using parpool (line 113)

Hello everyone,

I am trying to train a network using multiple GPUs, but I have problems in starting the parallel pool. When training on single GPU, everything goes well; although, I would like to use 2 of my available GPUs, not only one. So, I have seen that I must set up a parpool and then use gpuDevice(myGPUindex). I am quite a newbie, so maybe I am doing some trivial error.

When I run:

>> parpool('local', 2);

it gives me the following:

Starting parallel pool (parpool) using the 'local' profile ...
Connected to the parallel pool (number of workers: 2).
Error using parpool (line 113)
Parallel pool failed to start with the following error. For more detailed
information, validate the profile 'local' in the Cluster Profile Manager.

Caused by:
    Error using parallel.Future/fetchOutputs (line 347)
    One or more futures resulted in an error.
        Error using getCurrentJob (line 3)
        Not enough input arguments.
        Error using getCurrentJob (line 3)
        Not enough input arguments.

My version is MATLAB 2019b and I am on Ubuntu 18.04 LTS.

What am I doing wrong?

Answer 1

[Ilaria Tono]

As Joss Knight supposed, this was probably caused by an installation issue related to the Parallel Computing toolbox. I was suggested to try this workaround and then restart Matlab: it worked.

>>rehash toolboxcache
>>restoredefaultpath
>>savepath

For more problems involving the validation of the 'local' profile, I found this thread useful.

Answer 2

[Joss Knight]

This is a very unusual error and indicates a problem with your installation. I suspect your MATLAB path is mixed up with previous version of MATLAB or a pre-release install. You should contact MathWorks support.

[Ilaria Tono]

Thank you for your kind reply. I will try to figure it out with Mathworks support and then update the question!