maximize-cpu-freq

#!/usr/bin/env bash

set -euo pipefail

parse_params() {
	DRYRUN=0
	if [ "${1:-}" == '--dry-run' ]; then
		DRYRUN=1
		shift
	fi

	if [ "${1:-}" == '--help' ]; then
		echo "Usage: $0 [--dry-run]"
		exit 0
	fi
	
	if [ "$UID" != '0' ]; then
		echo "You should run this util as root. Use sudo/su."
		exit 1
	fi
}

set_governor_performance() {
	local gov_state
	local cpu="$1"
	local gov=$cpu/cpufreq/scaling_governor
	[ -f $gov ] || continue
	read gov_state < $gov
	if [ "$DRYRUN" = '0' ]; then
		if [ "$gov_state" != 'performance' ]; then
			echo "Set performance mode for $cpu governor"
			echo 'performance' > $gov
		fi
	fi
}

maximize_freq() {
	local cpu="$1"
	local max=$cpu/cpufreq/scaling_max_freq
	local min=$cpu/cpufreq/scaling_min_freq
	local cur=$cpu/cpufreq/scaling_cur_freq
	if [ ! -f $min ] || [ ! -f $max ]; then
		echo "$cpu doesn't support cpu scaling (and it's good)."
		continue
	fi
	echo "- set $cpu minimal freq ($(<$min)) to maximum ($(<$max))"
	if [ "$DRYRUN" = '0' ]; then
		cat $max > $min
	fi
}

main() {
	local cpu
	parse_params "$@"
	for cpu in $(find /sys/devices/system/cpu/ -maxdepth 1 -type d -name "cpu[0-9]*" | sort -V); do
		set_governor_performance "$cpu"
		maximize_freq "$cpu"
	done
}

main "$@"