Re: [PATCH] xenballoond: remove as it is now obsolete + unsupported code

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Mon, Apr 22, 2013 at 01:14:16PM +0100, Ian Campbell wrote:
> Dan, the author, states:
> > this code is five years old, is distro dependent, and is now
> > completely unsupported.
> 
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
> Cc: Konrad Wilk <konrad.wilk@oracle.com>

Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

This is already implemented in the Linux kernel.

> ---
> Dan says:
> I'd like to get Konrad's opinion first.
> 
> This kind of question seems to come up about once a year and its
> existence in the tree serves as a good example of what can be
> done with ballooning in legacy/unmodified Linux guests (e.g.
> shows how to write to the balloon driver via sysfs).
> 
> So I'll defer to your decision if Konrad agrees.
> ---
>  tools/xenballoon/xenballoon-monitor |   59 -------
>  tools/xenballoon/xenballoon.conf    |  136 -----------------
>  tools/xenballoon/xenballoond        |  283 -----------------------------------
>  tools/xenballoon/xenballoond.README |   85 -----------
>  tools/xenballoon/xenballoond.init   |   92 -----------
>  5 files changed, 0 insertions(+), 655 deletions(-)
>  delete mode 100644 tools/xenballoon/xenballoon-monitor
>  delete mode 100644 tools/xenballoon/xenballoon.conf
>  delete mode 100644 tools/xenballoon/xenballoond
>  delete mode 100644 tools/xenballoon/xenballoond.README
>  delete mode 100644 tools/xenballoon/xenballoond.init
> 
> diff --git a/tools/xenballoon/xenballoon-monitor b/tools/xenballoon/xenballoon-monitor
> deleted file mode 100644
> index c23cd39..0000000
> --- a/tools/xenballoon/xenballoon-monitor
> +++ /dev/null
> @@ -1,59 +0,0 @@
> -#!/bin/bash
> -#
> -# xenballoon-monitor - monitor certain stats from xenballoond
> -#   (run in dom0 with "watch -d xenballoon-monitor" for xentop-like output)
> -# updated 090610 to include tmem stats
> -#
> -# Copyright (C) 2009 Oracle Corporation and/or its affiliates.
> -# All rights reserved
> -# Written by: Dan Magenheimer <dan.magenheimer@oracle.com>
> -#
> -# Hint: Use "xm sched-credit -d 0 -w 2000" to watch on heavily loaded machines
> -#
> -TMEMTMP=$(/bin/mktemp -q /tmp/xenballoon-monitor.XXXXXX)
> -echo "id   mem-kb  tgt-kb  commit  swapin swapout    pgin    pgout  preswap  precache"
> -for i in `xenstore-list /local/domain`; do
> - if [ "$i" -ne 0 ]; then
> - tot=0; tgt=0; sin=0; sout=0; pgin=0; pgout=0; cmt=0; up=0; idle=0;
> - act=0; preswap=0; precache=0
> - if xenstore-exists /local/domain/$i/memory/meminfo; then
> -  tot=`xenstore-read /local/domain/$i/memory/meminfo | grep MemTotal \
> -   | sed 's/[^1-9]*\([1-9][0-9]*\).*/\1/'`
> -  cmt=`xenstore-read /local/domain/$i/memory/meminfo | grep Committed_AS \
> -   | sed 's/[^1-9]*\([1-9][0-9]*\).*/\1/'`
> - fi
> - if xenstore-exists /local/domain/$i/memory/selftarget; then
> -  tgt=`xenstore-read /local/domain/$i/memory/selftarget`
> - fi
> - if xenstore-exists /local/domain/$i/memory/vmstat; then
> -  sin=$(xenstore-read /local/domain/$i/memory/vmstat | tr '\\\n' '\n' \
> -	| grep pswpin | cut -d" " -f2)
> -  sout=$(xenstore-read /local/domain/$i/memory/vmstat | tr '\\\n' '\n' \
> -	| grep pswpout | cut -d" " -f2)
> -  pgin=$(xenstore-read /local/domain/$i/memory/vmstat | tr '\\\n' '\n' \
> -	| grep pgpgin | cut -d" " -f2)
> -  pgout=$(xenstore-read /local/domain/$i/memory/vmstat | tr '\\\n' '\n' \
> -	| grep pgout | cut -d" " -f2)
> - fi
> - xm tmem-list --all --long > $TMEMTMP
> - precache=`grep "C=CI:$i" $TMEMTMP | sed 's/C=CI.*Ec:\([0-9][0-9]*\).*/\1/'`
> - if xenstore-exists /local/domain/$i/memory/preswap; then
> -  preswap=`xenstore-read /local/domain/$i/memory/preswap`
> -  printf "%2d %8d%8d%8d%7d%8d%9d%9d%9d%9d\n" $i $tot $tgt $cmt $sin $sout $pgin $pgout $preswap $precache
> - else
> -  printf "%2d %8d%8d%8d%9d%9d%10d%10d\n" $i $tot $tgt $cmt $sin $sout $pgin $pgout
> - fi
> - fi
> -done
> -echo -n Free memory: `xm info | grep free | sed 's/[^1-9]*\([1-9][0-9]*\).*/\1/'` MiB "  "
> -tmem_free_pages=`grep "G=" $TMEMTMP | sed 's/G=.*Ta:\([0-9][0-9]*\).*/\1/'`
> -if [ ! -z "$tmem_free_pages" ]; then
> - let "tmem_free_mb=$tmem_free_pages/256"
> - echo -n Idle tmem: $tmem_free_mb MiB "  "
> -fi
> -tmem_eph_pages=`grep "G=" $TMEMTMP | sed 's/G=.*Ec:\([0-9][0-9]*\).*/\1/'`
> -if [ ! -z "$tmem_eph_pages" ]; then
> - let "tmem_eph_mb=$tmem_eph_pages/256"
> - echo -n Ephemeral tmem: $tmem_eph_mb MiB
> -fi
> -echo ""
> diff --git a/tools/xenballoon/xenballoon.conf b/tools/xenballoon/xenballoon.conf
> deleted file mode 100644
> index a1ca902..0000000
> --- a/tools/xenballoon/xenballoon.conf
> +++ /dev/null
> @@ -1,136 +0,0 @@
> -## Path: System/xen
> -## Description: xen domain start/stop on boot
> -## Type: string
> -## Default: 
> -
> -# NOTE: "xenbus is enabled" means not only that /proc/xen/xenbus exists
> -# but also that /usr/bin/xenstore-* tools are installed.
> -
> -## Type: boolean
> -## Default: false
> -#
> -# If XENBALLOON_SELF is true, selfballooning will occur, meaning the
> -# balloon driver will grow and shrink according to available memory.
> -# If xenbus is enabled, may be overridden by {memory/selfballoon}==0
> -# If false but xenballoond is able to communicate with domain0 via
> -# xenbus, balloon targets will be set by domain0
> -# 
> -XENBALLOON_SELF=false
> -
> -## Type: integer (must be > 0)
> -## Default: 1
> -#
> -# If self-ballooning, number of seconds between checks/adjustments.
> -# If xenbus is enabled, may be overridden by {memory/interval}
> -XENBALLOON_SELF_INTERVAL=1
> -
> -## Type: integer (must be > 0)
> -## Default: 1
> -#
> -# If NOT self-ballooning but xenbus is enabled, number of seconds between
> -# checks/adjustments. May be overridden by {memory/interval}
> -XENBALLOON_INTERVAL=1
> -
> -## Type: integer (must be > 0)
> -## Default: 10
> -#
> -# When current > target, reduces rate at which target memory is ballooned
> -# out.  For a value of n, 1/n of the difference will be ballooned.
> -# This value applies both to selfballooning and directed ballooning.
> -# May be overridden by {memory/downhysteresis}
> -XENBALLOON_AUTO_DOWNHYSTERESIS=10
> -
> -## Type: integer (must be > 0)
> -## Default: 1
> -#
> -# When current < target, reduces rate at which target memory is reclaimed
> -# (if available).  For a value of n, 1/n of the difference will be ballooned.
> -# This value applies both to selfballooning and directed ballooning.
> -# May be overridden by {memory/uphysteresis}
> -XENBALLOON_AUTO_UPHYSTERESIS=1
> -
> -## Type: integer (must be >= 0)
> -## Default: 0
> -#
> -# In order to avoid ballooning so much memory that a guest experiences
> -# out-of-memory errors (OOMs), memory will not be ballooned out below
> -# a minimum target, in MB.  If this value is 0 (default), an heuristic
> -# based on the maximum amount of memory will be used.  (The heuristic
> -# provides the same minimum as recent versions of the balloon driver but
> -# early versions of the balloon driver did not enforce a minimum.)
> -XENBALLOON_MINMEM=0
> -
> -## Type: string
> -## Default: "/var/run/xenballoon-maxmem"
> -#
> -# Location where memory high-water mark is stored; if a guest supports
> -# hot-add memory, maxmem might increase across time and the minimum
> -# target heuristic is based on max memory. NOTE: Reboot after changing
> -# this variable, else overballooning may occur.
> -XENBALLOON_MAXMEMFILE=/var/run/xenballoon-maxmem
> -
> -## Type: integer (0 or 1)
> -## Default: 1
> -#
> -# If xenbus is enabled, whether selfballooning or directed ballooning,
> -# place the result of 'cat /proc/meminfo" on xenbus at memory/meminfo
> -XENBALLOON_SEND_MEMINFO=1
> -
> -## Type: integer (0 or 1)
> -## Default: 1
> -#
> -# If xenbus is enabled, whether selfballooning or directed ballooning,
> -# place the result of 'cat /proc/vmstat" on xenbus at memory/vmstat
> -XENBALLOON_SEND_VMSTAT=1
> -
> -## Type: integer (0 or 1)
> -## Default: 1
> -#
> -# If xenbus is enabled, whether selfballooning or directed ballooning,
> -# place the result of 'cat /proc/uptime" on xenbus at memory/uptime
> -XENBALLOON_SEND_UPTIME=1
> -
> -## Type: boolean
> -## Default: false
> -#
> -# If tmem is running, pages swapped to a swap disk may instead go
> -# into preswap.  These pages may become stale (i.e. no longer need
> -# to be saved because, e.g., the process owning them has gone away)
> -# and stale pages use precious precious domain-allocated memory.
> -# Periodically try to reduce preswap to squeeze out stale pages
> -XENBALLOON_PRESWAP_SHRINK=false
> -
> -## Type: string
> -## Default: "/proc/sys/vm/preswap"
> -## (change to /sys/proc/vm/preswap in later kernels)
> -#
> -# If tmem and preswap are running, reading this file gives the number of
> -# pages currently in preswap.  Writing it with N invokes the preswap_shrink
> -# routine to reduce preswap to N pages.
> -XENBALLOON_PRESWAP_SYSFILE=/proc/sys/vm/preswap
> -
> -## Type: integer (must be > 0)
> -## Default: 20
> -#
> -# If tmem and preswap are running, attempts to reduce number of pages
> -# currently in preswap.  For a value of n, 1/n of the pages will
> -# be attempted to be shrunk.
> -# If xenbus is enabled, may be overridden by {memory/preswaphysteresis}
> -XENBALLOON_PRESWAP_HYSTERESIS=20
> -
> -## Type: integer (must be > 0)
> -## Default: 10
> -#
> -# Number of ballooning intervals where preswap size remains at N pages
> -# before preswap shrinking is attempted.  Also if shrinking fails to
> -# shrink to the target, counter resets to this value.
> -# If xenbus is enabled, may be overridden by {memory/preswapinertia}
> -XENBALLOON_PRESWAP_INERTIA=10
> -
> -## Type: integer (0 or 1)
> -## Default: 1
> -#
> -# If xenbus is enabled, whether selfballooning or directed ballooning,
> -# place the size of preswap (in pages) on xenbus at memory/preswap
> -XENBALLOON_SEND_PRESWAP=1
> -
> diff --git a/tools/xenballoon/xenballoond b/tools/xenballoon/xenballoond
> deleted file mode 100644
> index 121aa3e..0000000
> --- a/tools/xenballoon/xenballoond
> +++ /dev/null
> @@ -1,283 +0,0 @@
> -#!/bin/bash
> -#
> -# Copyright (C) 2008 Oracle Corporation and/or its affiliates.
> -# All rights reserved.
> -# Written by: Dan Magenheimer <dan.magenheimer@oracle.com>
> -#
> -# xenballoond - In-guest engine for Xen memory ballooning
> -# Original version: 080630
> -# Updated 0906XX: add tmem preswap auto-shrinking
> -#
> -# Two self-ballooning "policies" are implemented:
> -# - Selfballooning: Adjust memory periodically, with no (or little) input
> -#     from domain0.  Target memory is determined solely by the
> -#     Committed_AS line in /proc/meminfo, but parameters may adjust
> -#     the rate at which the target is achieved.
> -# - Directed ballooning: Adjust memory solely as directed by domain0
> -#
> -# Under some circumstances, "output" may also be generated; the contents
> -# of /proc/meminfo and /proc/vmstat may be periodically placed on xenbus.
> -#
> -# If xenbus is running and the /usr/bin/xenstore-* tools are installed,
> -# "xenbus is enabled".
> -#
> -# Parameters are documented in <SYSCONFIG>/xenballoon.conf. Although
> -# some are not used with directed ballooning, all must be set properly.
> -# If xenbus is enabled, some of these parameters may be overridden by values
> -# set by domain0 via xenbus.
> -
> -minmb() {
> -	RETVAL=$XENBALLOON_MINMEM
> -	if [ $RETVAL -ne 0 ]; then
> -		return $RETVAL
> -	fi
> -	kb=`cat $XENBALLOON_MAXMEMFILE`
> -	let "mb=$kb/1024"
> -	let "pages=$kb/4"
> -	# this algorithm from drivers/xen/balloon/balloon.c:minimum_target()
> -	# which was added to balloon.c in 2008 to avoid ballooning too small
> -	# it is unnecessary here except to accomodate pre-2008 balloon drivers
> -	# note that ranges are adjusted because a VM with "memory=1024"
> -	# gets somewhat less than 1024MB
> -	if [ $mb -lt 125 ]; then
> -		let RETVAL="$(( 8 + ($pages >> 9) ))"
> -	elif [ $mb -lt 500 ]; then
> -		let RETVAL="$(( 40 + ($pages >> 10) ))"
> -	elif [ $mb -lt 2000 ]; then
> -		let RETVAL="$(( 104 + ($pages >> 11) ))"
> -	else
> -		let RETVAL="$(( 296 + ($pages >> 13) ))"
> -	fi
> -	return	# value returned in RETVAL in mB
> -}
> -
> -curkb() {
> -	kb=`grep MemTotal /proc/meminfo | sed 's/  */ /' | \
> -		cut -f2 -d' '`
> -	RETVAL=$kb
> -	return  # value returned in RETVAL in kB
> -}
> -
> -downhysteresis() {
> -	RETVAL=$XENBALLOON_AUTO_DOWNHYSTERESIS
> -	if [ $xenstore_enabled = "true" ]; then
> -		if xenstore-exists memory/downhysteresis ; then
> -			RETVAL=`xenstore-read memory/downhysteresis`
> -		fi
> -	fi
> -	return
> -}
> -
> -uphysteresis() {
> -	RETVAL=$XENBALLOON_AUTO_UPHYSTERESIS
> -	if [ $xenstore_enabled = "true" ]; then
> -		if xenstore-exists memory/uphysteresis ; then
> -			RETVAL=`xenstore-read memory/uphysteresis`
> -		fi
> -	fi
> -	return
> -}
> -
> -selfballoon_eval() {
> -	if [ $xenstore_enabled = "true" ]; then
> -		if xenstore-exists memory/selfballoon; then
> -			RETVAL=`xenstore-read memory/selfballoon`
> -			if [ $RETVAL -eq 1 ]; then
> -				selfballoon_enabled=true
> -				return
> -			fi
> -		fi
> -	fi
> -	selfballoon_enabled=$XENBALLOON_SELF
> -	return
> -}
> -
> -selftarget() {
> -	tgtkb=`grep Committed_AS /proc/meminfo | sed 's/  */ /' | cut -f2 -d' '`
> -	minmb
> -	let "minbytes=$RETVAL*1024*1024"
> -	let "tgtbytes=$tgtkb*1024"
> -	if [ $tgtbytes -lt $minbytes ]; then
> -		let "tgtbytes=$minbytes"
> -	fi
> -	RETVAL=$tgtbytes  # value returned in RETVAL in bytes
> -	return
> -}
> -
> -# $1 == 1 means use selftarget, else target in kB
> -balloon_to_target() {
> -	if [ "$1" -eq 1 ]; then
> -		selftarget
> -		tgtbytes=$RETVAL
> -	else
> -		let "tgtbytes=$(( $1 * 1024 ))"
> -	fi
> -	curkb
> -	let "curbytes=$RETVAL*1024"
> -	if [ $curbytes -gt $tgtbytes ]; then
> -		downhysteresis
> -		downhys=$RETVAL
> -		if [ $downhys -ne 0 ]; then
> -			let "tgtbytes=$(( $curbytes - \
> -				( ( $curbytes - $tgtbytes ) / $downhys ) ))"
> -		fi
> -	else if [ $curbytes -lt $tgtbytes ]; then
> -		uphysteresis
> -		uphys=$RETVAL
> -		let "tgtbytes=$(( $curbytes + \
> -				( ( $tgtbytes - $curbytes ) / $uphys ) ))"
> -		fi
> -	fi
> -	echo $tgtbytes > /proc/xen/balloon
> -	if [ $xenstore_enabled = "true" ]; then
> -		let "tgtkb=$(( $tgtbytes/1024 ))"
> -		xenstore-write memory/selftarget $tgtkb
> -	fi
> -}
> -
> -send_memory_stats() {
> -	if [ ! $xenstore_enabled = "true" ]; then
> -		return
> -	fi
> -	if [ $XENBALLOON_SEND_MEMINFO ]; then
> -		xenstore-write memory/meminfo "`cat /proc/meminfo`"
> -	fi
> -	if [ $XENBALLOON_SEND_VMSTAT ]; then
> -		xenstore-write memory/vmstat "`cat /proc/vmstat`"
> -	fi
> -	if [ $XENBALLOON_SEND_UPTIME ]; then
> -		xenstore-write memory/uptime "`cat /proc/uptime`"
> -	fi
> -}
> -
> -
> -curpreswappages() {
> -	pages=$(cat $XENBALLOON_PRESWAP_SYSFILE)
> -	RETVAL=$pages
> -	return  # value returned in RETVAL in pages
> -}
> -
> -preswaphysteresis() {
> -	RETVAL=$XENBALLOON_PRESWAP_HYSTERESIS
> -	if [ $xenstore_enabled = "true" ]; then
> -		if xenstore-exists memory/preswaphysteresis ; then
> -			RETVAL=`xenstore-read memory/preswaphysteresis`
> -		fi
> -	fi
> -	return
> -}
> -
> -preswapinertia() {
> -	RETVAL=$XENBALLOON_PRESWAP_INERTIA
> -	if [ $xenstore_enabled = "true" ]; then
> -		if xenstore-exists memory/preswapinertia ; then
> -			RETVAL=`xenstore-read memory/preswapinertia`
> -		fi
> -	fi
> -	return
> -}
> -
> -send_preswap_stats() {
> -	if [ ! $xenstore_enabled = "true" ]; then
> -		return
> -	fi
> -	curpreswappages
> -	preswap_pgs=$RETVAL
> -	if [ $XENBALLOON_SEND_PRESWAP ]; then
> -		xenstore-write memory/preswap "$preswap_pgs"
> -	fi
> -}
> -
> -shrink_preswap() {
> -	if [ "$XENBALLOON_PRESWAP_SHRINK" = "false" ]; then
> -		return
> -	fi
> -	if [ ! -f "$XENBALLOON_PRESWAP_SYSFILE" ]; then
> -		return
> -	fi
> -	curpreswappages
> -	preswaplast=$preswapnow
> -	preswapnow=$RETVAL
> -	if [ $preswapnow -eq 0 -o $preswapnow -ne $preswaplast ]; then
> -		preswapinertia
> -		preswapinertiacounter=$RETVAL
> -		return
> -	fi
> -	let "preswapinertiacounter=$preswapinertiacounter-1"
> -	if [ $preswapinertiacounter -ne 0 ]; then
> -		return
> -	fi
> -	preswaphysteresis
> -	preswaphys=$RETVAL
> -	if [ $preswaphys -eq 0 ]; then
> -		return
> -	fi
> -	let "tgtpreswappages=$(( $preswapnow - \
> -				( $preswapnow / $preswaphys ) ))"
> -	preswapinertia
> -	preswapinertiacounter=$RETVAL
> -	echo $tgtpreswappages > "$XENBALLOON_PRESWAP_SYSFILE"
> -}
> -
> -if [ ! -f /proc/xen/balloon ]; then
> -	echo "$0: no balloon driver installed"
> -	exit 0
> -fi
> -if [ ! -f /proc/meminfo ]; then
> -	echo "$0: can't read /proc/meminfo"
> -	exit 0
> -fi
> -xenstore_enabled=true
> -if [ -f /usr/bin/xenstore-exists -a -f /usr/bin/xenstore-read -a \
> -     -f /usr/bin/xenstore-write ]; then
> -	xenstore_enabled=true
> -else
> -	echo "$0: missing /usr/bin/xenstore-* tools, disabling directed ballooning"
> -	xenstore_enabled=false
> -fi
> -preswapnow=0
> -
> -# See docs/misc/distro_mapping.txt
> -if [ -f /etc/sysconfig/xenballoon.conf ]; then
> -	. /etc/sysconfig/xenballoon.conf
> -elif [ -f /etc/default/xenballoon.conf ]; then
> -	. /etc/default/xenballoon.conf
> -fi
> -
> -while true;
> -do
> -	# handle special case for PV domains with hot-add memory
> -	if [ ! -f $XENBALLOON_MAXMEMFILE ]; then
> -		maxkb=0
> -	else
> -		maxkb=`cat $XENBALLOON_MAXMEMFILE`
> -	fi
> -	curkb=`grep MemTotal /proc/meminfo | sed 's/  */ /' | cut -f2 -d' '`
> -	if [ $curkb -gt $maxkb ]; then
> -		echo $curkb > $XENBALLOON_MAXMEMFILE
> -	fi
> -	interval=$XENBALLOON_INTERVAL
> -	# do self-ballooning
> -	selfballoon_eval
> -	if [ $selfballoon_enabled = "true" ]; then
> -		balloon_to_target 1
> -		interval=$XENBALLOON_SELF_INTERVAL
> -	# or do directed ballooning
> -	elif [ $xenstore_enabled = "true" ]; then
> -		if xenstore-exists memory/target ; then
> -			tgtkb=`xenstore-read memory/target`
> -			balloon_to_target $tgtkb
> -		fi
> -		interval=$XENBALLOON_INTERVAL
> -	fi
> -	shrink_preswap
> -	send_memory_stats
> -	send_preswap_stats
> -	if [ $xenstore_enabled = "true" ]; then
> -		if xenstore-exists memory/interval ; then
> -			interval=`xenstore-read memory/interval`
> -		fi
> -	fi
> -	sleep $interval
> -done &
> -
> diff --git a/tools/xenballoon/xenballoond.README b/tools/xenballoon/xenballoond.README
> deleted file mode 100644
> index 9084898..0000000
> --- a/tools/xenballoon/xenballoond.README
> +++ /dev/null
> @@ -1,85 +0,0 @@
> -Xenballoond.README
> -Preliminary version 0.1, 2008/06/30
> -
> -Copyright (C) 2008 Oracle Corporation and/or its affiliates.
> -All rights reserved.
> -Written by Dan Magenheimer <dan.magenheimer@oracle.com>
> -
> -INTRODUCTION
> -
> -Xenballoond runs in guest domains and both implements selfballooning and
> -provides metrics to dom0 for (future) directed ballooning.  Both capabilities
> -provide a foundation for basic "memory overcommit" functionality.
> -
> -With selfballooning enabled, xenballoond uses the Committed_AS value found
> -in /proc/meminfo as a first approximation of how much memory is required
> -by the guest and feeds this statistic back to the balloon driver to inflate
> -or deflate the balloon as required to achieve the target guest memory size.
> -Hysteresis parameters may be adjusted to rate-limit balloon inflation
> -and deflation.
> -
> -If configured, certain selfballooning parameters -- including notably
> -enabling/disabling of self-ballooning -- can be controlled from domain0.
> -(These are fully documented in xenballoon.conf.)
> -
> -If configured, the following guest statistics are sent back to domain0:
> -- /proc/meminfo
> -- /proc/vmstat
> -- /proc/uptime
> -In a future release, some of these values will be used by a policy module
> -in domain0 to control guest balloon size and provide memory balancing
> -across all guests on a given system.
> -
> -Note that no page sharing (content-based or otherwise) is implemented
> -and no VMM-based swapping is necessary.
> -
> -For more information, see:
> -http://www.xen.org/files/xensummitboston08/MemoryOvercommit-XenSummit2008.pdf
> -http://wiki.xensource.com/xenwiki/Open_Topics_For_Discussion?action=AttachFile&do=get&target=Memory+Overcommit.pdf
> -
> -INSTALLATION AND DEPLOYMENT
> -
> -In this preliminary release:
> -- directed ballooning is not implemented, though a monitor is provided
> -- only Redhat-based guests are supported
> -
> -Guest prerequisites to use xenballoond:
> -- each guest must be configured with adequate[1] swap space
> -- each guest must have the balloon driver installed (/proc/xen/balloon exists) 
> -- if directed ballooning (or monitoring) is desired, xenstore tools must be
> -  installed in each guest in /usr/bin [2]
> -
> -[1] for best results, for a guest that is configured with maxmem=N and
> -    requires Z MB of swap space without xenballoond, available swap should
> -    be increased to N+Z MB when xenballoond is running
> -[2] specifically xenstore-read, xenstore-exists, and xenstore-write must
> -    be installed.  Binaries can be obtained, for example, by building
> -    xen-vvv.gz/tools in a guest-binary-compatible development tree
> -
> -Instructions to install/deploy xenballoond:
> -  (see docs/misc/distro_mapping.txt for SYSCONFIG and INITD_DIR definitions)
> -- in each guest:
> -  - ensure pre-requisites are met (see above)
> -  - place xenballoon.conf in <SYSCONFIG>
> -  - place xenballoond in /usr/sbin
> -  - copy xenballoond.init to <INITD_DIR>/xenballoond (note file rename)
> -  - edit <SYSCONFIG>/xenballoond.conf as desired (especially note that
> -    selfballooning defaults as off)
> -  - start xenballoond with "service xenballoond start", and/or configure
> -    xenballoond to start at init
> -        (Red Hat e.g. "chkconfig xenballoond on")
> -        (Debian e.g. " update-rc.d xenballoond defaults")
> -        (Suse e.g. " insserv xenballoond")
> -- in domain0:
> -  - if monitoring is desired, xenballoon-monitor may be installed in /usr/sbin
> -- note that certain xenballoond.conf variables may be overridden by domain0
> -  if xenstore is running in the guest; these are fully documented in
> -  xenballoond.conf
> -
> -TODO:
> -080630 domain0 ballooning policy module
> -080630 experiment with more aggressive (optionally) memory minimum targets
> -080630 BUG: xenballoond doesn't properly record the fact that it's running;
> -       e.g. flipping between run levels 5 and 3 launches additional daemons
> -080630 BUG: reports of possible incompatibilites between ballooning and
> -       save/restore/migrate have not been duplicated
> diff --git a/tools/xenballoon/xenballoond.init b/tools/xenballoon/xenballoond.init
> deleted file mode 100644
> index 5cd0fb3..0000000
> --- a/tools/xenballoon/xenballoond.init
> +++ /dev/null
> @@ -1,92 +0,0 @@
> -#!/bin/bash
> -#
> -# xenballoond	Script to start and stop Xen ballooning daemon.
> -#
> -# Copyright (C) 2009 Oracle Corporation and/or its affiliates.
> -# All rights reserved.
> -# Written by: Dan Magenheimer <dan.magenheimer@oracle.com>
> -#
> -# chkconfig: 2345 98 01
> -# description: Starts and stops the Xen ballooning daemon.
> -### BEGIN INIT INFO
> -# Provides:          xenballoond
> -# Required-Start:    $syslog $remote_fs
> -# Should-Start:
> -# Required-Stop:     $syslog $remote_fs
> -# Should-Stop:
> -# Default-Start:     3 5
> -# Default-Stop:      0 1 2 6
> -# Short-Description: Start/stop xenballoond
> -# Description:       Starts and stops the Xen ballooning daemon.
> -### END INIT INFO
> -
> -# Source function library
> -. /etc/init.d/functions
> -
> -#don't use in domain0
> -[ -f /proc/xen/capabilities ] && \
> -	grep -q "control_d" /proc/xen/capabilities && exit 0
> -
> -if [ -f /etc/sysconfig/xenballoon.conf ]; then
> -	. /etc/sysconfig/xenballoon.conf
> -elif [ -f /etc/default/xenballoon.conf ]; then
> -	. /etc/default/xenballoon.conf
> -fi
> -
> -# Check that balloon driver is present
> -[ ! -f /proc/xen/balloon ] && exit 0
> -
> -# Record original memory (in kB)
> -[ -z "$XENBALLOON_MAXMEMFILE" ] && exit 0
> -let maxmem=`grep MemTotal /proc/meminfo | sed 's/  */ /' | cut -f2 -d' '`
> -if [ -f "$XENBALLOON_MAXMEMFILE" ]; then
> -	let oldmax=`cat $XENBALLOON_MAXMEMFILE`
> -	if [ $oldmax -gt $maxmem ]; then
> -		let maxmem=oldmax
> -	fi
> -fi
> -echo $maxmem > $XENBALLOON_MAXMEMFILE
> -
> -RETVAL=0
> -prog="xenballoond"
> -
> -start() {
> -        # Start daemons.
> -        echo -n $"Starting $prog: "
> -        daemon xenballoond $OPTIONS
> -	RETVAL=$?
> -        echo
> -	return $RETVAL
> -}
> -
> -stop() {
> -        echo -n $"Shutting down $prog: "
> -	killproc xenballoond
> -	RETVAL=$?
> -        echo
> -	return $RETVAL
> -}
> -
> -# See how we were called.
> -case "$1" in
> -  start)
> -	start
> -        ;;
> -  stop)
> -	stop
> -        ;;
> -  status)
> -	status xenballoond
> -	RETVAL=$?
> -	;;
> -  restart|reload)
> -	stop
> -	start
> -	RETVAL=$?
> -	;;
> -  *)
> -        echo $"Usage: $0 {start|stop|restart|status}"
> -        exit 1
> -esac
> -
> -exit $RETVAL
> -- 
> 1.7.2.5
>