#!/bin/bash

MAXCPUS=12

# find cpus

CPUS=`ls -d /sys/devices/system/cpu/cpu[1-9]*`
NR=`echo $CPUS | wc -w`

let x=0
for cpu in $CPUS; do
    file=$cpu/online
    CPUONLINE[$x]=$file
    ENB[$x]=`cat $file`
    CPU[$x]=`basename $cpu`
    let x=$x+1
done

let MAXCNT=$x

MSKCNT=$MAXCNT

if [ $MAXCNT -gt $MAXCPUS ]; then
    MSKCNT=$MAXCPUS
fi

let MSKCNT=2**$MSKCNT

hotplug() {
    MSK=$1
    ECHO="$MSK"
    CMD=""
    x=0
    while [ $MSK -gt 0 ]; do
	let bit=$MSK'&'1
	if [ $bit -eq 1 ]; then
	    if [ ${ENB[$x]} -eq 1 ]; then
		cmd="disabling"
		ENB[$x]=0
		num=0
	    else
		cmd="enabling"
		ENB[$x]=1
		num=1
	    fi
	    CMD="$CMD echo $num > ${CPUONLINE[$x]};"
	    ECHO="$ECHO $cmd ${CPU[$x]}"
	fi
	let x=$x+1
	let MSK=$MSK'>>'1
    done
    echo $ECHO
    eval $CMD
}

let MSKCNT=$MSKCNT-1
for i in `seq $MSKCNT`; do
    hotplug $i
done
for i in `seq $MSKCNT`; do
    hotplug $i
done

exit 0