[pymvpa] how to do multiprocessing in pymvpa?

Nick Oosterhof nikolaas.oosterhof at unitn.it
Tue Feb 5 10:49:42 UTC 2013


On 4 February 2013 20:14, Meng Liang <meng.liang at hotmail.co.uk> wrote:
> Once I added 'nproc = 3' in the command [...] then the script seems to just hang there. It looks to me that there is
> no computing actually running because I don't see any CPU usage from the
> Activity Monitor of the Mac machine.
>
> Any idea what's going wrong?

By setting nproc explicitly to an integer > 1 the expression
"pprocess.get_number_of_cores()" (which gave an error for not finding
/proc/cpuinfo on your mac) is not evaluated.

Then it continues happily, and I suppose pprocess forks of its
processes and then dies gracefully - due to no/poor support on the
mac.

Did you see if there are any processes running after starting the
searchlight - e.g. using 'top' or 'ps'?

In any case, if you want to use multicore support on the mac I suggest
to install virtualbox and run neurodebian virtually. I'm using a mac
myself and that works fine.



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