ps call missing processes in Yocto - process

Question

I'm trying to report on running processes in Yocto (Poky). ps aux doesn't work here, but standard ps call return much of what aux would in Debian. But it won't report my .sh script processes. Is there an argument that works here, or another call I can try? Thanks in advance.

Answer 1

You are probably using busybox. Busybox contains its own version of ps and might not have support for the flags you're using. A simple ls -l /bin/ps should give you indications whether or not it's symlinked to busybox or not.
My suggestion would be to include the package procps in your recipe (which contains the ps you're more familiar with).

Answer 2

Busybox ps should show you all your processes.
I've created this test script, pstest.sh:
#!/bin/sh
while true; do
sleep 10;
done
Which I've been running, both on a Debian box, aon a qemux86 based core-image-minimal, and on a custom embedded device built with OpenEmbedded / Yocto. (I.e. the last one is not running the Yocto kernel). On all of these devices, the following holds true:
# ./pstest.sh &
# ps
PID USER VSZ STAT COMMAND
1 root 4196 S {systemd} /sbin/init
2 root 0 SW [kthreadd]
3 root 0 SW [ksoftirqd/0]
5 root 0 SW< [kworker/0:0H]
.....
633 root 2452 S {pstest.sh} /bin/sh ./pstest.sh
634 root 2732 S sleep 10
638 root 3044 R ps
As you can see, I'm seeing the script process, as well as the sleep command. (Note: on Debian ps above has been replaced with busybox ps).
If you still can only see the sleep, could you try the following:
# cat /proc/`pidof sleep`/status | grep PPid
PPid: 633
By running that line, you should be able to see the parent PID of the sleep command; check which process that corresponds to.