dump1090-fa CPU overloading


#1

hello, i built a reciever using an orange pi zero with 256mb of RAM. the board mounts an Alwinner H2+ quad core cpu. I noticed that the process started by dump1090-fa insanely overloads the CPU causing the temperatures to grow up (Orange pi zero have some thermal problems, and this continuos overload is not good!). How i can solve this problem? i attach some photos of the process and dump-1090 settings:

CPU load:http://i68.tinypic.com/ra0phh.png

Dump1090-fa settings:http://i64.tinypic.com/2hoenar.pngthanks


#2

The demodulation work is fundamentally expensive to do, you can’t avoid it. 50-60% of one core is about right for these types of ARM CPU.


#3

The cpu is quad core, where do you see that the process is using only 1 core? thanks


#4

It’s not tied to one core, but the 68% CPU number is expressed as a percentage of a single CPU, not as a percentage of the whole system.
The summary lines at the very top show the overall system use (75% idle)

If you want to show process CPU use as a percentage of the whole system, turn off “Irix mode” (capital I in top)
Or you can see a per-CPU breakdown by hitting ‘1’


#5

I happen to run exactly the same Orange PI Zeros with my trackers and I do not observe such a high CPU load.
Whats the temperature that your OPI is running on low and high load?

My OPIs are normally in the 30-70 Celsius range…


#6

In addition to the first post I noticed similar behavior of a dump1090-fa on Opi PC (H3; 1GB RAM; Linux OrangePI 3.4.39 #1 SMP PREEMPT Mon Oct 12 12:02:29 CEST 2015 armv7l armv7l armv7l GNU/Linux;Ubuntu 15.04 Vivid Vervet; Piaware 3.5.0 add-on, dump1090-fa included)
Until yesterday it worked fine except that CPU load was around 40%-48% (with temp 55-60degC) so it seemed normally but little odd because on another OpiOne (H3 512MB RAM) CPU load is 20-28%, and on other RPi (1GB RAM) is also 20-28% all 3 are getting similar count of planes so there is no significant difference in environment.
Yesterday there was a drop in planes and no planes on Skyviewat all. Piaware logged loss of connection to dump1090-fa. Checking the working processes revealed that dump109-fa was overloading CPU reaching 100-104% the CPU with temp respectively reached 75-76deg C. After stopping piaware and restarting dump1090-fa interactively it worked for a while with CPU load reaching 50-60% and plane/flight data scrolled on the screen. Then stopped with ‘segmentation fault’ message probably due to high temp reaching fast the limit of CPU and/or RAM.
Does anybody have idea why dump1090-fa on this particular installation loads CPU twice than on others?


#7

Seems the reason would have been loose usb connection to the dongle.
Today it is no longer possible to start dump1090-fa. It gives following:
-------------
rtlsdr: using device #0: Generic RTL2832U (Realtek, RTL2832U, SN 00001000)
Found Rafael Micro R820T tuner
rtlsdr: tuner gain set to 49.6 dB
cb transfer status: 1, canceling…
cb transfer status: 1, canceling…
Mon Jun 4 15:41:58 2018 EEST No data received from the SDR for a long time, it may have wedged
-------------------
CPU hitting 100% and temp reached 78degC in 30 sec.

The site is remote so I can not check right now.


#8

All is working as before but question still stays
Why this dump1090-fa here is loading CPU twice than on other setups ~~ 40% vs 20%
Any idea where to dig?