CPU utilization repeatedly ramps to 100% using MODEP

CPU utilization repeatedly ramps to 100%, (approx. every 10 seconds) and multiple xruns occur while using MODEP, with or without plugins added to the signal path. I’ve tried re-flashing the patchbox OS image a couple times and run into the same problem. I’m running the 2020-11-23 image of patchbox OS, and had successfully used this image until the last few re-flash attempts. I’m using an Rpi 3b+. Any ideas how to troubleshoot? Thank you!

Run top in a terminal and try to see which processes get CPU usage spikes.

Giedrius, thanks for quick reply. Below is the worst-case CPU useage that I could capture. As you can see, it doesn’t come close to 100% useage, so I can’t see any obvious CPU-hungry culprits via the “top” command…

  PID USER      PR  NI    VIRT    RES    SHR S  **%CPU**  %MEM     TIME+ COMMAND
 2530 root      20   0       0      0      0 I  **10.6**   0.0   1:28.13 kworker/2:5-mm_percpu_wq
  465 jack      20   0  131116  92120  84732 S   **7.6**   9.7   2:11.38 jackd
  124 root      20   0   41440  14072  13128 S   **1.3**   1.5   0:11.40 systemd-journal
 2672 modep     20   0  131368  89160  84076 S   **1.0**   9.4   0:07.86 mod-host
  380 root      20   0   25512   2324   1616 S   **0.7**   0.2   0:04.26 rsyslogd
  811 root      20   0   43592   2612   2044 S   **0.7**   0.3   0:22.46 mec-app
 3082 patch     20   0   10428   3052   2504 R   **0.7**   0.3   0:00.77 top
  233 root      20   0       0      0      0 S   **0.3**   0.0   0:00.20 brcmf_wdog/mmc1
 2675 modep     20   0  136700 118652  92880 S   **0.3**  12.5   0:05.29 mod-ui
    1 root      20   0   34864   6488   4580 S   **0.0**   0.7   0:16.87 systemd
    2 root      20   0       0      0      0 S   **0.0**   0.0   0:00.01 kthreadd
    3 root       0 -20       0      0      0 I   **0.0**   0.0   0:00.00 rcu_gp
    4 root       0 -20       0      0      0 I   **0.0**   0.0   0:00.00 rcu_par_gp

Btw, you can hit ‘enter’ while top is running to instantly refresh, instead of the fixed update interval, this way you may be able to spot something just at the right moment.

Got it. I can’t tell what was causing the spikes but I was booting from a USB stick . I’ve reproduced the issue re-flashing ~5 times consecutively on one particular USB 2.0 stick. I’ve since stopped using this stick and am not having the issue anymore. Thanks for the help, Giedrius.

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