Eric Blossom wrote: > On Tue, Jan 06, 2009 at 11:20:48PM -0500, Marcus D. Leech wrote: > >> Eric Blossom wrote: >> >>> Is this an SMP machine, or a cluster? >>> >>> If SMP, it'll "just work". If it's a cluster, you'll need to figure >>> out how to partition separate instantiations of GR on each node. >>> >>> Eric >>> >> SMP. >> >> Describe how it'll "just work"?? >> >> Maybe I haven't looked at all the blocks carefully enough, but I can't >> immediately see how to do this. >> >> I basically want a "distributor" block that distributes FFT input frames >> to multiple instances of an FFT computation, >> across multiple threads, and have the results of the separate FFTs >> synchronized. >> > > Sounds good. Sorry, I misunderstood your goal. > (I'm working on the guts of FFTW now and have FFT on the brain...) > > I think we have the blocks you need to do the fanout and fanin > already. They're disguised as > > gr.deinterleave(itemsize) > gr.interleave(itemsize) > > I think you could use them like this: > > fft_size = 512 > > usrp = ... > > fanout = gr.deinterleave(fft_size * gr.sizeof_complex) > fanin = gr.interleave(fft_size * gr.sizeof_complex) > > fft0 = ... > fft1 = ... > fft2 = ... > fft3 = ... > > connect(usrp, fanout) > > connect((fanout, 0), fft0) > connect((fanout, 1), fft1) > connect((fanout, 2), fft2) > connect((fanout, 3), fft3) > > connect(fft0, (fanin, 0)) > connect(fft1, (fanin, 1)) > connect(fft2, (fanin, 2)) > connect(fft3, (fanin, 3)) > > > Each block runs in its own thread, so this should run faster on an SMP > machine. Please let us know if this works for you! > > [FYI, there are also two extra copies happening in the gr.fft_* block that I > now know how to remove...] > > Eric > > Yes, I came to the same conclusion about gr.interleave trickery myself, and will have to noodle over it when I'm awake.
-- Marcus Leech Principal Investigator, Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
