for cpu_dir in /sys/devices/system/cpu/cpu[0-9]* do online_file="$cpu_dir"/online [ -f "$online_file" ] && [ "$(cat "$online_file")" -eq 0 ] && continue file="$cpu_dir"/cpufreq/scaling_governor [ -f "$file" ] && echo "performance" > "$file" done "phoronix-test-suite" "run" "iozone-1.9.5"