On Fri, May 21, 2010 at 02:15:15PM -0700, Veljko Pejovic wrote: > Hi, > > I'm using two USRP2 with XCVR2450s, a week old gnuradio git master and > Ubuntu 9.10. > > A few months ago while using the OFDM code I observed that I tend to > receive (or send?) packets in groups, although I was sending them > individually. > > Now, I finally isolated the problem. I added a few simple print lines: > > "Message inserted in HAVE_HEADER" - whenever a message is enqueued in > STATE_HAVE_SYNC of ofdm_frame_sink.cc > > and > > "Message picked up from the queue" - in queue_watcher_thread in > ofdm.py, every time the message is fetched from the queue. > > The output that I expected was: > > Message inserted in HAVE_HEADER > Message picked up from the queue > Message inserted in HAVE_HEADER > Message picked up from the queue > ... > > However, I'm getting rather inconsistent output (this is a sample, > check the attachment for the first few seconds of the output): > > Message inserted in HAVE_HEADER > Message inserted in HAVE_HEADER > Message inserted in HAVE_HEADER > Message inserted in HAVE_HEADER > Message picked up from the queue > Message picked up from the queue > Message picked up from the queue > Message picked up from the queue > Message inserted in HAVE_HEADER > Message inserted in HAVE_HEADER > Message inserted in HAVE_HEADER > Message inserted in HAVE_HEADER > Message inserted in HAVE_HEADER > Message picked up from the queue > Message picked up from the queue > Message picked up from the queue > Message picked up from the queue > Message picked up from the queue > > So, it is definitely the receiver that has problems. It looks as if > "msg = self.rcvd_pktq.delete_head()" in queue_watcher_thread in > ofdm.py is not checked frequently enough. Could it be that Python does > not switch threads fast enough? Note, I do have real time scheduling > enabled. > Any ideas on how to get around this?
Is your machine out of CPU cycles? If it's not fast enough, it won't keep up. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
