#!/bin/bash

#

# ksm          Kernel Samepage Merging

#

# Author:      Dan Kenigsberg <danken@redhat.com>

#

# Copyright 2009 Red Hat, Inc. and/or its affiliates.

# Released under the GPL

#

# chkconfig: 345 84 16

# description: The KSM init script starts and stops the ksm kernel thread.

# config: /etc/sysconfig/ksm

#

### BEGIN INIT INFO

# Provides: ksm

# Required-Start:

# Required-Stop:

# Should-Start:

# Default-Start: 3 4 5

# Short-Description: start and stop ksm

# Description: The KSM init script starts and stops the ksm kernel thread.

### END INIT INFO

. /etc/rc.d/init.d/functions

if [ -f /etc/sysconfig/ksm ]; then

    . /etc/sysconfig/ksm

fi

prog=ksm

RETVAL=0

# unless KSM_MAX_KERNEL_PAGES is set, let ksm munch up to half of total memory.

default_max_kernel_pages () {

    local total pagesize

    total=`awk '/^MemTotal:/ {print $2}' /proc/meminfo`

    pagesize=`getconf PAGESIZE`

    echo $[total * 1024 / pagesize / 2]

}

start() {

    echo -n $"Starting $prog: "

    KSM_MAX_KERNEL_PAGES=${KSM_MAX_KERNEL_PAGES:-`default_max_kernel_pages`}

    echo $KSM_MAX_KERNEL_PAGES > /sys/kernel/mm/ksm/max_kernel_pages

    echo 1 > /sys/kernel/mm/ksm/run

    RETVAL=$?

    [ $RETVAL = 0 ] && success $"$prog startup" || failure $"$prog startup"

    echo

}

stop() {

    echo -n $"Stopping $prog: "

    echo 0 > /sys/kernel/mm/ksm/run

    RETVAL=$?

    [ $RETVAL = 0 ] && success $"$prog shutdown" || failure $"$prog shutdown"

    echo

}

status() {

    if [ ! -f /sys/kernel/mm/ksm/run ] ; then

        echo $"$prog not supported"

        RETVAL=1

    else if [ "$(cat /sys/kernel/mm/ksm/run 2>/dev/null)" != "1" ]; then

        echo $"$prog is not running"

        RETVAL=1

    else

        echo $"$prog is running"

        RETVAL=0

    fi; fi

}

restart() {

    stop

    start

}

case "$1" in

  start)

	start

	;;

  stop)

	stop

	;;

  status)

        status

	;;

  restart)

	restart

	;;

  condrestart|try-restart)

	status >/dev/null 2>&1 || exit 0

	restart

        ;;

  force-reload)

	restart

	;;

  *)

	echo $"Usage: $prog {start|stop|restart|force-reload|condrestart|try-restart|status|help}"

	RETVAL=2

esac

exit $RETVAL