Just a final update about this journey to control the CPU Frequency governor.
I have settled on the use of rc.local.
Please note that since I removed the Panel Applet for the governor 2 months ago, and using the setup described below, there have been no mysterious "interventions" changing my governor from "userspace" to "ondemand".
So ... that means that something associated with the Applet is triggering those "downgrades". I don't know what and, at this point, with nothing else having changed, it doesn't matter to me anymore.
But ... those that do use the Panel Applet for their governor use may wish to be aware of that "unexplained" behaviour.
Thanks again to everyone for your help.
Here is a summary of my notes regarding the setup, in case anyone else wants to replicate. My final script can be obtained here.
####################################################################################################
[1] Source: cpufrequtils [distro package]
This files ensures the proper module is loaded into the kernel for CPU Frequency governor.
/etc/init.d/loadcpufreq
####################################################################################################
[2] Source: cpufrequtils [distro package]
This file initializes the CPU Frequeny governor profile and settings.
/etc/init.d/cpufrequtils
####################################################################################################
[3] Source: local [ custom script ]
This script "manages" the CPU Frequency governor according to local preferences.
${Oasis}/bin/HW_Admin__Power_SetFreqCPU.sh
####################################################################################################
[4] Source: local [ custom script ]
This file ensures that the script 'HW_Admin__Power_SetFreqCPU.sh' is started at boot time with user specifications.
/etc/rc.local
|| /DB001_F2/Oasis/bin/HW_Admin__Power_SetFreqCPU.sh --default --service
####################################################################################################
[5] Source: local [ custom config ]
This crontab entry "monitors" the CPU Frequency governor, thereby making possible to confirm stability.
|| 0,10,20,30,40,50 * * * * /DB001_F2/Oasis/bin/HW_Admin__Power_SetFreqCPU.sh --status --cron