[Discuss-gnuradio] "D" errors after flowgraph runs for some time

[John Ackermann N8UR]

I am playing with a slightly modified version of Chris Kuethe's 
channelizer example for NOAA radio stations (my version attached).  I'm 
using 3.7.6.1.

The program runs just fine for the first 20-30 minutes on my I7-4710HQ 
laptop.  System monitor shows typically one core running at about 50% 
with the others ranging from idling to 30%.  Only a fraction of system 
memory is used.  The laptop is wired to a USRP2/WBX via GigE switch, and 
is showing about 5MIB/s of incoming data when the flowgraph is running.

But after 20-30 minutes I start to get a string of "D"s on the console, 
and while the program keeps decoding audio, the signal strength drops by 
40dB or more.

When I first started playing with Chris' example, I also had a string of 
"D"s immediately upon startup which I cured by turning on realtime 
scheduling.  It appears that just moved the problem off into the future.

I am guessing this is some sort of buffer exhaustion or similar problem. 
 Any suggestions on how to address is?

Thanks,
John

noaa_demo.grc
Description: application/gnuradio-grc