using the on_movie_end option in the config creates zombie processes

[steffhip]

0. Reviewed guide and contributing documents? (Yes/No): Yes
1. version [x.y.z, hash, other]: deafult raspberryPi version: 4.3.2
2. installed as a package or compiled from sources [deb, rpm, git, other]: from raspberrypi repo
3. standalone or part of third party [motion, MotionEyeOS, other]: standalone
4. video stream source [V4L (card or USB), net cam (mjpeg, rtsp, other), mmal]: legacy camera stack
5. hardware [x86, ARM, other]: arm64 / raspberrypi 3
6. operating system [16.04, Stretch, etc, FreeBSD, other]: debian11 (bullseye)

To reproduce the issue, just add an simple on_movie_end option (in my case: touch %f.done to signalize another script that the file is written). The script itself is executed properly. However a zombie process remains after each execution.

eg. ps aux yields after this stage:

[...]
motion   1234 0.0 0.0  0   0   ?   Zs 22.18 0:00 [sh] <defunct>
[...]

[Mr-Dave]

I'm not seeing this on my machine so some additional specifics would be needed. Full log, exact script, paths, precise detail steps to reproduce, validation it occurs with most recent version, etc.

[steffhip]

Indeed I found out that this issue only appears if motion itself is started with the libcamerify wrapper (which even isn't needed when using the legacy camera stack with /dev/video0 on the raspi).
So most likely this is not an issue with motion itself but with the libcamerify wrapper.
So most likely this issue can be closed. Sorry for the wrong ticket ....

[AntiSol]

@steffhip I'm also seeing this issue for other types of events, e.g picture_save. See: motioneye-project/motioneye#2900

Did you have any luck in tracking down the cause and fixing this issue? I wasn't able to find any issues on the libcamera library which seem to match this, and I don't know how I would go about confirming whether the problem is in the motion daemon or libcamerify.

@Mr-Dave I've tried to provide the requested info, hopefully this helps?

0. validation it occurs with most recent version: yep, I just tried installing the pi-bookworm deb from the releases page.

1. exact script: doesn't matter. You'll get zombies if your script is

#!/bin/bash
exit 0

but you can see the exact script here: https://github.com/motioneye-project/motioneye/blob/main/motioneye/scripts/relayevent.sh

2. steps to reproduce(?):
   a. set motion to run the above bash script on picture_save, and to save a picture every 30 seconds
   b. run motion via libcamerafy (on a raspi4 with raspbian bookworm and a v3 pi camera)

As indicated above I'm seeing this when running motion via motioneye. In the motion config, the on_picture_save line looks like this:

on_picture_save /usr/local/lib/python3.11/dist-packages/motioneye/scripts/relayevent.sh "/etc/motioneye/motioneye.conf" picture_save %t %f

3. motion log:

[0:motion] [NTC] [ALL] conf_load: Processing thread 0 - config file /etc/motioneye/motion.conf
[0:motion] [NTC] [ALL] config_camera: Processing camera config file camera-1.conf
[0:motion] [NTC] [ALL] motion_startup: Logging to syslog
[0:motion] [NTC] [ALL] motion_startup: Motion 4.6.0 Started
[0:motion] [NTC] [ALL] motion_startup: Using default log type (ALL)
[0:motion] [NTC] [ALL] motion_startup: Using log type (ALL) log level (WRN)
[1:27:22.339612806] [12958] ERROR IPAModule ipa_module.cpp:172 Symbol ipaModuleInfo not found
[1:27:22.339688843] [12958] ERROR IPAModule ipa_module.cpp:292 v4l2-compat.so: IPA module has no valid info
[1:27:22.339782565] [12958]  INFO Camera camera_manager.cpp:284 libcamera v0.2.0+46-075b54d5
[1:27:22.477882865] [12959]  WARN RPiSdn sdn.cpp:39 Using legacy SDN tuning - please consider moving SDN inside rpi.denoise
[1:27:22.480211131] [12959]  INFO RPI vc4.cpp:447 Registered camera /base/soc/i2c0mux/i2c@1/imx708@1a to Unicam device /dev/media4 and ISP device /dev/media1
[1:27:22.481349088] [12958]  INFO Camera camera.cpp:1183 configuring streams: (0) 1280x720-YUV420
[1:27:22.483564429] [12959]  INFO RPI vc4.cpp:611 Sensor: /base/soc/i2c0mux/i2c@1/imx708@1a - Selected sensor format: 1536x864-SBGGR10_1X10 - Selected unicam format: 1536x864-pBAA
[1:ml1:Rear] [ERR] [VID] v4l2_fps_set: Error setting fps. Return code -1
[1:27:22.485672974] [12958]  INFO Camera camera.cpp:1183 configuring streams: (0) 1280x720-YUV420
[1:27:22.486047898] [12959]  INFO RPI vc4.cpp:611 Sensor: /base/soc/i2c0mux/i2c@1/imx708@1a - Selected sensor format: 1536x864-SBGGR10_1X10 - Selected unicam format: 1536x864-pBAA

Hopefully this is useful? Please HMU if there's more I can do to help track this down :)

[kbingham]

[1:ml1:Rear] [ERR] [VID] v4l2_fps_set: Error setting fps. Return code -1

I don't think setting the FPS is handled by libcameraify (the libcamera-v4l2 wrapper layer) yet. Not many people have used libcamerify - and the more correct route is to use libcamera API's directly, not go through libcamerify.

That said, if you want to investigate this - take a look at https://patchwork.libcamera.org/patch/15392/ - It looks like that's a patch that implements what you need, but seems like it never got merged.

If you test it, and it works - please report that back to the libcamera-devel list and we can see what's needed to get it integrated, or what additional work is required on top of that.