Re: Maximum Number of Bins

[Criss Swaim]

we are running version 3.7.9.2

Criss Swaim
cswaim@tpginc.net
cell: 505.301.5701

On 10/29/2020 11:37 AM, Marcus D. Leech wrote:

On 10/29/2020 01:17 PM, Criss Swaim wrote:

I have attached a png of the flow graph and the error msgs from the system log are below.  These error messages are the only messages.

Oct 29 10:45:26 tf abrt-hook-ccpp[378]: /var/spool/abrt is 23611049718 bytes (more than 1279MiB), deleting 'ccpp-2020-10-27-15:30:43-28474'
Oct 29 10:45:07 tf abrt-hook-ccpp[378]: Process 329 (python2.7) of user 1000 killed by SIGSEGV - dumping core
Oct 29 10:45:07 tf audit[370]: ANOM_ABEND auid=1000 uid=1000 gid=1000 ses=8656 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 pid=370 comm="copy11" exe="/usr/bin/Oct 29 10:45:07 tf audit[369]: ANOM_ABEND auid=1000 uid=1000 gid=1000 ses=8656 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 pid=369 comm="analysis_sink_1" exe="Oct 29 10:45:07 tf kernel: traps: copy11[370] general protection ip:7f9e0acfdee0 sp:7f9c5a7fb590 error:0 in libpthread-2.22.so[7f9e0acf1000+18000]
Oct 29 10:45:07 tf kernel: analysis_sink_1[369]: segfault at 7f9c5a7fd000 ip 00007f9dd9361d43 sp 00007f9c5a48a638 error 6 in libgnuradio-vandevender.so[7f9dd9336000+4d000]

Flow is USRP -> stream to vector -> fft -> complex to mag -> bin_sub_avg -> analysis_sinkf

bin_sub_avg (python) & analysis_sinkf (c/c++) are custom blocks.

the function of Bin Sub Avg, which is written in Python, is to start a background task which periodically (in this case hourly) samples the input signal, calculates the background noise and subtracts it from the signal that is passed the the Analysis_sinkf module.

Analys_sinkf monitors each bin and only when specific thresholds for the bin are met (ie duration, strength) is the signal written out to a signal file.  Signals not passing the criteria are dropped.

This code base has been running for over 3 years, with the original system implementation about 8/9 years ago.

I have traced the problem to the input signal into bin_sub_avg when the number of fft bins is 3 million (2 million works).  At 3 million bins, any reference to the result of the delete_head() function in the python code causes a failure.  The python code just fails without a traceback, then the invalid data stream is passed to the analysis_sinkf module which is C/C++ and it causes the segment fault.

Thus my suspicion is there is a limit in the fft block on the number of bins it can handle and some variable is overflowing, but this is a guess at this point.  There may be a restriction in the gr.signature_io module, but that seems unlikely.

What version of Gnu Radio is this?