# Benchmark\_rx.py segmentation fault **URL:** \ **Category:** GNU Radio\ **Created:** [April 30, 2015, 6:00pm UTC](https://www.ruby-forum.com/t/benchmark-rx-py-segmentation-fault/241792 "2015-04-30T18:00:47Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![musicdenotation](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea666f/32.png) [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Post date:** [April 30, 2015, 6:00pm UTC](https://www.ruby-forum.com/t/benchmark-rx-py-segmentation-fault/241792/1 "2015-04-30T18:00:47Z")
Hello, I’m using Ubuntu 14.04, gnuradio 3.7.8, USRP N210 and the latest UHD. Everything was recently (3 days ago) updated to newest versions and USRP’s reflashed. I have custom flowgraphs that use the USRP N210’s that work fine. I decided to play around with the benchmark\_tx and benchmark\_rx scripts to see what they could do, but I’m not able to receive anything because a segmentation fault crashes the benchmark\_rx script as soon as I start the tx script. Even with the -v flag, I don’t get any error output other then ‘Segmentation fault (core dumped)’. Here is an example of the commands I use to start the scripts. I start the rx and then the tx. TX: _./benchmark\_tx.py -v -f 1000000000 -r 800000 --args=“addr=10.0.8.5” -A TX/RX --tx-gain=15_ RX: \*./benchmark\_rx.py -v -f 1000000000 -r 800000 --args=“addr=10.0.8.4” -A RX2 --rx-gain=15 \* Am I doing something wrong on my end or is there a script issue? Thanks, Rich ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [May 1, 2015, 7:22pm UTC](https://www.ruby-forum.com/t/benchmark-rx-py-segmentation-fault/241792/2 "2015-05-01T19:22:00Z")
Did you update GNU Radio _after_ you updated UHD? If not, that’s what you should do. [http://gnuradio.org/redmine/projects/gnuradio/wiki/FAQ#My-application-segfaults-immediately-It-used-to-work-and-I-didnt-change-it-What-the](http://gnuradio.org/redmine/projects/gnuradio/wiki/FAQ#My-application-segfaults-immediately-It-used-to-work-and-I-didnt-change-it-What-the) M ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [May 1, 2015, 7:47pm UTC](https://www.ruby-forum.com/t/benchmark-rx-py-segmentation-fault/241792/3 "2015-05-01T19:47:43Z")
I use pybombs to update, which automatically updates UHD first and then GNU Radio. Rich On Fri, May 1, 2015 at 10:20 AM, Martin B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [May 1, 2015, 8:56pm UTC](https://www.ruby-forum.com/t/benchmark-rx-py-segmentation-fault/241792/4 "2015-05-01T20:56:03Z")
OK, then I have no clue. If you can present a stack trace here, someone might have a better idea. Cheers, Martin ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [May 1, 2015, 9:53pm UTC](https://www.ruby-forum.com/t/benchmark-rx-py-segmentation-fault/241792/5 "2015-05-01T21:53:54Z")
I remember I had the same issue before when testing the benchmark. What I did to avoid the crash is to start the tx first, and then the rx. It seems that you are doing it in reverse order, which is reasonable but not working according to my test. On Fri, May 1, 2015 at 10:51 AM, Richard B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![reback](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b5ac83/32.png) [@reback](https://www.ruby-forum.com/u/reback)\ **Post date:** [May 1, 2015, 8:02pm UTC](https://www.ruby-forum.com/t/benchmark-rx-py-segmentation-fault/241792/6 "2015-05-01T20:02:19Z")
I forgot to mention that I also re-cloned pybombs before doing the update. So to be explicit, I deleted the target and pybombs directory. I then re-cloned pybombs and performed a new ./pybombs install gnuradio. This recognized I had all dependencies installed via rpm and only needed to remove and re-install uhd and gnuradio. It then did this. As I mentioned, my custom radio flowgraph is working on this updated system. v/r, Rich On Fri, May 1, 2015 at 10:46 AM, Richard B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)