| #!/bin/bash |
| # Copyright 2014 the V8 project authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| CPUPATH=/sys/devices/system/cpu |
| |
| MAXID=$(cat $CPUPATH/present | awk -F- '{print $NF}') |
| |
| set_governor() { |
| echo "Setting CPU frequency governor to \"$1\"" |
| for (( i=0; i<=$MAXID; i++ )); do |
| echo "$1" > $CPUPATH/cpu$i/cpufreq/scaling_governor |
| done |
| } |
| |
| enable_cores() { |
| # $1: How many cores to enable. |
| for (( i=1; i<=$MAXID; i++ )); do |
| if [ "$i" -lt "$1" ]; then |
| echo 1 > $CPUPATH/cpu$i/online |
| else |
| echo 0 > $CPUPATH/cpu$i/online |
| fi |
| done |
| } |
| |
| dual_core() { |
| echo "Switching to dual-core mode" |
| enable_cores 2 |
| } |
| |
| single_core() { |
| echo "Switching to single-core mode" |
| enable_cores 1 |
| } |
| |
| |
| all_cores() { |
| echo "Reactivating all CPU cores" |
| enable_cores $((MAXID+1)) |
| } |
| |
| |
| limit_cores() { |
| # $1: How many cores to enable. |
| echo "Limiting to $1 cores" |
| enable_cores $1 |
| } |
| |
| case "$1" in |
| fast | performance) |
| set_governor "performance" |
| ;; |
| slow | powersave) |
| set_governor "powersave" |
| ;; |
| default | ondemand) |
| set_governor "ondemand" |
| ;; |
| dualcore | dual) |
| dual_core |
| ;; |
| singlecore | single) |
| single_core |
| ;; |
| allcores | all) |
| all_cores |
| ;; |
| limit_cores) |
| if [ $# -ne 2 ]; then |
| echo "Usage $0 limit_cores <num>" |
| exit 1 |
| fi |
| limit_cores $2 |
| ;; |
| *) |
| echo "Usage: $0 fast|slow|default|singlecore|dualcore|all|limit_cores" |
| exit 1 |
| ;; |
| esac |