Small script to set CPU EPP (tested on amd-pstate-epp)

eppSetup.sh

#!/bin/bash

# path to relevant sysfs parameters
eppPath=/sys/devices/system/cpu/cpufreq

# read available EPP profiles from cpu0
if [ -e "$eppPath"/policy0/energy_performance_available_preferences ]; then
     availableEPP=$(sed -e 's/ *$//' -e 's/ /|/g' <<<$(cat "$eppPath"/policy0/energy_performance_available_preferences))
else
     echo "EPP parameters not found. Check if scaling governor supports EPP and if eppPath in script is correct"
     exit 1
fi

# check input for specified EPP, otherwise use power EPP
shopt -s extglob
availableEPPglob='@('$availableEPP')'
case $1 in
     -h|--help)
     echo "Sets the EPP of all cpus to the desired level."
     echo "Example: eppSetup.sh balance_performance"
     echo "Sets the EPP to balance_performance"
     echo "Valid arguments are: $availableEPP"
     exit 0
     ;;
     $availableEPPglob)
     pref="$1"
     ;;
     *)
     pref=power
     ;;
esac

# check if the script is run as root
if [ "$(whoami)" != "root" ]; then
	echo "You need to run the script with root privileges. Attempting to raise via sudo:"
	sudo "${0}" "$@"
	exit $?
fi

# set EPP on all CPUs
for cpuX in "$eppPath"/policy*; do
     echo "$pref" > "$cpuX"/energy_performance_preference
done

echo "Set EPP to $pref"
exit 0