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#!/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
|
