Re: [Discuss-gnuradio] Parallel programming

[Marcus D. Leech]

On 01/10/2011 03:11 PM, sirjanselot wrote:
> How do I know that my flow-graph is executing in thread per block mode?
>
> As far as I can tell my only 1 core out of the 8 is being used when I run my
> flow-graphs.  This is what I see when I run the performance monitor (or
> whatever it is called) in Ubuntu.
>
> I am currently using gnuradio 3.3.0 as my version.
>
> So can I parallelize my block without having to create a meta-block as you
> say?  I have a lot of for-loops and vector calculations that need to be
> optimized (adaptive fir filters).
By default, each flow-graph is assigned its own thread.  It's up to the 
kernel to schedule these as it sees fit.

Getting parallelism *inside your own custom block* is something you'll 
have to deal with yourself.

I've done experiments with using the multi-threaded FFTW libraries for 
very large transforms, which causes
  internal parallelism with the FFTW library.  This works, and doesn't 
appear to adversely affect Gnu Radio
  thread-per-block scheduling.

The thread-per-block scheduler is the default behaviour, so the reason 
you may only be seeing one core in use is just
  due to the dynamic behaviour of your flowgraph.



--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org