On 09/04/2010 08:08 PM, Tom Rondeau wrote: > On Sat, Sep 4, 2010 at 12:19 AM, Marcus D. Leech <mle...@ripnet.com> wrote > > Like Eric said, remove the throttle or at least change the rate and > that should clean things up. > > Tom > > I also noted in the reply to Eric that I observe the same behaviour with an external source that is producing 4800 symbols/second--so it's not the throttle *per se*, but rather the way that work "chunks" get scheduled in Gnu Radio. With a "fast" source, you dont find yourself in a situation where there aren't enough "chunks" to keep things busy.
But a very reasonable example would be something like a cross-band digital repeater application, where bits/symbols would be arriving at the "channel rate", and need to leave the Tx in something at least approaching real time--you certainly need to have a bit of elastic buffering to compensate for clock-skew between the two sides, but several-tens-of-seconds of latency isn't likely to be very useful in the real world. Note that I'm not criticizing anybody or anything. I'm making observations, and I *do* understand *why* it is the way it is. My little test flow-graph failed the "least astonishment test", which is why I felt I needed to comment. Would it be reasonable to open a discussion about this class of flow-graph? I think they can be characterized as flow-graphs with a low symbol rate, and high interpolation (which I think is where the buffer-multiplier effect may be coming into play). In such flow-graphs, would it be reasonable to be able to "tweak" the scheduler to deal with this type of situation? I have little insight into how the scheduler works in detail, but I think I understand the "fits and starts" that I was observing. So, is this a reasonable discussion topic? Are other folks working on "stuff" that will run into part of the performance diagram I ran into yesterday? Or is everyone else working on high-event-rate type signal chains? Cheers -- 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
