The short story
---------------
-If you just want to use it, run the laptop_mode control script (which is included
-at the end of this document) as follows:
+To use laptop mode, you don't need to set any kernel configuration options
+or anything. You simply need to run the laptop_mode control script (which
+is included in this document) as follows:
# laptop_mode start
* If you have your filesystems listed as type "auto" in fstab, like I did, then
the control script will not recognize them as filesystems that need remounting.
-* If you have XFS, make SURE that you set the XFS_HZ value in the control script
- correctly, to the value of HZ of your running kernel. Laptop mode will not
- work correctly if it is set too low, and you may lose data if it is set too
- high. The reason for this problem is that XFS does not export its sysctl
- variables in centisecs (like most other subsystems do) but in "jiffies",
- which is an internal kernel measure. Once this is fixed things will get better.
+* It has been reported that some versions of the mutt mail client use file access
+ times to determine whether a folder contains new mail. If you use mutt and
+ experience this, you must disable the noatime remounting in the control script
+ by setting DO_REMOUNT_NOATIME=0.
The details
-----------
-Laptop-mode is controlled by the flag /proc/sys/vm/laptop_mode. When this
-flag is set, any physical disk read operation (that might have caused the
-hard disk to spin up) causes Linux to flush all dirty blocks. The result
-of this is that after a disk has spun down, it will not be spun up anymore
-to write dirty blocks, because those blocks had already been written
-immediately after the most recent read operation
+Laptop-mode is controlled by the flag /proc/sys/vm/laptop_mode. This flag is
+present for all kernels that have the laptop mode patch, regardless of any
+configuration options. When the flag is set, any physical disk read operation
+(that might have caused the hard disk to spin up) causes Linux to flush all dirty
+blocks. The result of this is that after a disk has spun down, it will not be spun
+up anymore to write dirty blocks, because those blocks had already been written
+immediately after the most recent read operation.
To increase the effectiveness of the laptop_mode strategy, the laptop_mode
control script increases dirty_expire_centisecs and dirty_writeback_centisecs in
Please note that this control script works for the Linux 2.4 and 2.6 series.
--------------------CONTROL SCRIPT BEGIN------------------------------------------
-#! /bin/sh
+#!/bin/bash
# start or stop laptop_mode, best run by a power management daemon when
# ac gets connected/disconnected from a laptop
# Bart Samwel
# Micha Feigin
# Andrew Morton
+# Herve Eychenne
# Dax Kelson
#
# Original Linux 2.4 version by: Jens Axboe
+#############################################################################
+
+# Age time, in seconds. should be put into a sysconfig file
+MAX_AGE=600
+
+# Read-ahead, in kilobytes
+READAHEAD=4096
+
+# Shall we remount journaled fs. with appropiate commit interval? (1=yes)
+DO_REMOUNTS=1
+
+# And shall we add the "noatime" option to that as well? (1=yes)
+DO_REMOUNT_NOATIME=1
+
+# Dirty synchronous ratio. At this percentage of dirty pages the process which
+# calls write() does its own writeback
+DIRTY_RATIO=40
+
+#
+# Allowed dirty background ratio, in percent. Once DIRTY_RATIO has been
+# exceeded, the kernel will wake pdflush which will then reduce the amount
+# of dirty memory to dirty_background_ratio. Set this nice and low, so once
+# some writeout has commenced, we do a lot of it.
+#
+DIRTY_BACKGROUND_RATIO=5
+
+# kernel default dirty buffer age
+DEF_AGE=30
+DEF_UPDATE=5
+DEF_DIRTY_BACKGROUND_RATIO=10
+DEF_DIRTY_RATIO=40
+DEF_XFS_AGE_BUFFER=15
+DEF_XFS_SYNC_INTERVAL=30
+DEF_XFS_BUFD_INTERVAL=1
+
+# This must be adjusted manually to the value of HZ in the running kernel
+# on 2.4, until the XFS people change their 2.4 external interfaces to work in
+# centisecs. This can be automated, but it's a work in progress that still needs
+# some fixes. On 2.6 kernels, XFS uses USER_HZ instead of HZ for external
+# interfaces, and that is currently always set to 100. So you don't need to
+# change this on 2.6.
+XFS_HZ=100
+
+#############################################################################
+
+KLEVEL="$(uname -r |
+ {
+ IFS='.' read a b c
+ echo $a.$b
+ }
+)"
+case "$KLEVEL" in
+ "2.4"|"2.6")
+ ;;
+ *)
+ echo "Unhandled kernel version: $KLEVEL ('uname -r' = '$(uname -r)')" >&2
+ exit 1
+ ;;
+esac
+
+if [ ! -e /proc/sys/vm/laptop_mode ] ; then
+ echo "Kernel is not patched with laptop_mode patch." >&2
+ exit 1
+fi
+
+if [ ! -w /proc/sys/vm/laptop_mode ] ; then
+ echo "You do not have enough privileges to enable laptop_mode." >&2
+ exit 1
+fi
+
# Remove an option (the first parameter) of the form option=<number> from
# a mount options string (the rest of the parameters).
parse_mount_opts () {
OPT="$1"
shift
- echo "$*" | \
- sed 's/.*/,&,/' | \
- sed 's/,'"$OPT"'=[0-9]*,/,/g' | \
- sed 's/,,*/,/g' | \
- sed 's/^,//' | \
- sed 's/,$//' | \
- cat -
+ echo ",$*," | sed \
+ -e 's/,'"$OPT"'=[0-9]*,/,/g' \
+ -e 's/,,*/,/g' \
+ -e 's/^,//' \
+ -e 's/,$//'
}
# Remove an option (the first parameter) without any arguments from
parse_nonumber_mount_opts () {
OPT="$1"
shift
- echo "$*" | \
- sed 's/.*/,&,/' | \
- sed 's/,'"$OPT"',/,/g' | \
- sed 's/,,*/,/g' | \
- sed 's/^,//' | \
- sed 's/,$//' | \
- cat -
+ echo ",$*," | sed \
+ -e 's/,'"$OPT"',/,/g' \
+ -e 's/,,*/,/g' \
+ -e 's/^,//' \
+ -e 's/,$//'
}
# Find out the state of a yes/no option (e.g. "atime"/"noatime") in
# If fstab contains, say, "rw" for this filesystem, then the result
# will be "defaults,atime".
parse_yesno_opts_wfstab () {
- L_DEV=$1
- shift
- OPT=$1
- shift
- DEF_OPT=$1
- shift
+ L_DEV="$1"
+ OPT="$2"
+ DEF_OPT="$3"
+ shift 3
L_OPTS="$*"
PARSEDOPTS1="$(parse_nonumber_mount_opts $OPT $L_OPTS)"
PARSEDOPTS1="$(parse_nonumber_mount_opts no$OPT $PARSEDOPTS1)"
# Watch for a default atime in fstab
- FSTAB_OPTS="$(cat /etc/fstab | sed 's/ / /g' | grep ^\ *"$L_DEV " | awk '{ print $4 }')"
- if [ -z "$(echo "$FSTAB_OPTS" | grep "$OPT")" ] ; then
- # option not specified in fstab -- choose the default.
- echo "$PARSEDOPTS1,$DEF_OPT"
- else
+ FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)"
+ if echo "$FSTAB_OPTS" | grep "$OPT" > /dev/null ; then
# option specified in fstab: extract the value and use it
- if [ -z "$(echo "$FSTAB_OPTS" | grep "no$OPT")" ] ; then
+ if echo "$FSTAB_OPTS" | grep "no$OPT" > /dev/null ; then
+ echo "$PARSEDOPTS1,no$OPT"
+ else
# no$OPT not found -- so we must have $OPT.
echo "$PARSEDOPTS1,$OPT"
- else
- echo "$PARSEDOPTS1,no$OPT"
fi
+ else
+ # option not specified in fstab -- choose the default.
+ echo "$PARSEDOPTS1,$DEF_OPT"
fi
}
# If fstab contains, say, "commit=3,rw" for this filesystem, then the
# result will be "rw,commit=3".
parse_mount_opts_wfstab () {
- L_DEV=$1
- shift
- OPT=$1
- shift
+ L_DEV="$1"
+ OPT="$2"
+ shift 2
L_OPTS="$*"
-
PARSEDOPTS1="$(parse_mount_opts $OPT $L_OPTS)"
# Watch for a default commit in fstab
- FSTAB_OPTS="$(cat /etc/fstab | sed 's/ / /g' | grep ^\ *"$L_DEV " | awk '{ print $4 }')"
- if [ -z "$(echo "$FSTAB_OPTS" | grep "$OPT=")" ] ; then
- # option not specified in fstab: set it to 0
- echo "$PARSEDOPTS1,$OPT=0"
- else
+ FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)"
+ if echo "$FSTAB_OPTS" | grep "$OPT=" > /dev/null ; then
# option specified in fstab: extract the value, and use it
echo -n "$PARSEDOPTS1,$OPT="
- echo "$FSTAB_OPTS" | \
- sed 's/.*/,&,/' | \
- sed 's/.*,'"$OPT"'=//' | \
- sed 's/,.*//' | \
- cat -
+ echo ",$FSTAB_OPTS," | sed \
+ -e 's/.*,'"$OPT"'=//' \
+ -e 's/,.*//'
+ else
+ # option not specified in fstab: set it to 0
+ echo "$PARSEDOPTS1,$OPT=0"
fi
}
-KLEVEL="$(uname -r | cut -c1-3)"
-case "$KLEVEL" in
- "2.4"|"2.6")
- true
- ;;
- *)
- echo "Unhandled kernel version: $KLEVEL ('uname -r' = '$(uname -r)')"
- exit 1
- ;;
-esac
-
-# Shall we remount journaled fs. with appropiate commit interval? (1=yes)
-DO_REMOUNTS=1
-
-# age time, in seconds. should be put into a sysconfig file
-MAX_AGE=600
-
-# Dirty synchronous ratio. At this percentage of dirty pages the process which
-# calls write() does its own writeback
-DIRTY_RATIO=40
-
-#
-# Allowed dirty background ratio, in percent. Once DIRTY_RATIO has been
-# exceeded, the kernel will wake pdflush which will then reduce the amount
-# of dirty memory to dirty_background_ratio. Set this nice and low, so once
-# some writeout has commenced, we do a lot of it.
-#
-DIRTY_BACKGROUND_RATIO=5
-
-READAHEAD=4096 # kilobytes
-
-# kernel default dirty buffer age
-DEF_AGE=30
-DEF_UPDATE=5
-DEF_DIRTY_BACKGROUND_RATIO=10
-DEF_DIRTY_RATIO=40
-DEF_XFS_AGE_BUFFER=15
-DEF_XFS_SYNC_INTERVAL=30
-
-# This must be adjusted manually to the value of HZ in the running kernel,
-# until the XFS people change their external interfaces to work in centisecs
-# like the rest of the external world. Unfortunately this cannot be automated. :(
-XFS_HZ=1000
-if [ ! -e /proc/sys/vm/laptop_mode ]; then
- echo "Kernel is not patched with laptop_mode patch."
- exit 1
-fi
-
-if [ ! -w /proc/sys/vm/laptop_mode ]; then
- echo "You do not have enough privileges to enable laptop_mode."
- exit 1
+if [ $DO_REMOUNT_NOATIME -eq 1 ] ; then
+ NOATIME_OPT=",noatime"
fi
case "$1" in
echo -n "Starting laptop_mode"
if [ -d /proc/sys/vm/pagebuf ] ; then
+ # (For 2.4 and early 2.6.)
# This only needs to be set, not reset -- it is only used when
# laptop mode is enabled.
echo $XFS_AGE > /proc/sys/vm/pagebuf/lm_flush_age
echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval
elif [ -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
+ # (A couple of early 2.6 laptop mode patches had these.)
# The same goes for these.
echo $XFS_AGE > /proc/sys/fs/xfs/lm_age_buffer
echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval
elif [ -f /proc/sys/fs/xfs/age_buffer ] ; then
+ # (2.6.6)
# But not for these -- they are also used in normal
# operation.
echo $XFS_AGE > /proc/sys/fs/xfs/age_buffer
echo $XFS_AGE > /proc/sys/fs/xfs/sync_interval
+ elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then
+ # (2.6.7 upwards)
+ # And not for these either. These are in centisecs,
+ # not USER_HZ, so we have to use $AGE, not $XFS_AGE.
+ echo $AGE > /proc/sys/fs/xfs/age_buffer_centisecs
+ echo $AGE > /proc/sys/fs/xfs/xfssyncd_centisecs
+ echo 3000 > /proc/sys/fs/xfs/xfsbufd_centisecs
fi
case "$KLEVEL" in
"2.4")
- echo "1" > /proc/sys/vm/laptop_mode
+ echo 1 > /proc/sys/vm/laptop_mode
echo "30 500 0 0 $AGE $AGE 60 20 0" > /proc/sys/vm/bdflush
;;
"2.6")
- echo "5" > /proc/sys/vm/laptop_mode
+ echo 5 > /proc/sys/vm/laptop_mode
echo "$AGE" > /proc/sys/vm/dirty_writeback_centisecs
echo "$AGE" > /proc/sys/vm/dirty_expire_centisecs
echo "$DIRTY_RATIO" > /proc/sys/vm/dirty_ratio
case "$FST" in
"ext3"|"reiserfs")
PARSEDOPTS="$(parse_mount_opts commit "$OPTS")"
- mount $DEV -t $FST $MP -o remount,$PARSEDOPTS,commit=$MAX_AGE,noatime
+ mount $DEV -t $FST $MP -o remount,$PARSEDOPTS,commit=$MAX_AGE$NOATIME_OPT
;;
"xfs")
- mount $DEV -t $FST $MP -o remount,$OPTS,noatime
+ mount $DEV -t $FST $MP -o remount,$OPTS$NOATIME_OPT
;;
esac
if [ -b $DEV ] ; then
U_AGE=$((100*$DEF_UPDATE))
B_AGE=$((100*$DEF_AGE))
echo -n "Stopping laptop_mode"
- echo "0" > /proc/sys/vm/laptop_mode
- if [ -f /proc/sys/fs/xfs/age_buffer ] && [ ! -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
- # These need to be restored though, if there are no lm_*.
- echo "$(($XFS_HZ*$DEF_XFS_AGE_BUFFER))" > /proc/sys/fs/xfs/age_buffer
- echo "$(($XFS_HZ*$DEF_XFS_SYNC_INTERVAL))" > /proc/sys/fs/xfs/sync_interval
+ echo 0 > /proc/sys/vm/laptop_mode
+ if [ -f /proc/sys/fs/xfs/age_buffer -a ! -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
+ # These need to be restored, if there are no lm_*.
+ echo $(($XFS_HZ*$DEF_XFS_AGE_BUFFER)) > /proc/sys/fs/xfs/age_buffer
+ echo $(($XFS_HZ*$DEF_XFS_SYNC_INTERVAL)) > /proc/sys/fs/xfs/sync_interval
+ elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then
+ # These need to be restored as well.
+ echo $((100*$DEF_XFS_AGE_BUFFER)) > /proc/sys/fs/xfs/age_buffer_centisecs
+ echo $((100*$DEF_XFS_SYNC_INTERVAL)) > /proc/sys/fs/xfs/xfssyncd_centisecs
+ echo $((100*$DEF_XFS_BUFD_INTERVAL)) > /proc/sys/fs/xfs/xfsbufd_centisecs
fi
case "$KLEVEL" in
"2.4")
echo "$DEF_DIRTY_BACKGROUND_RATIO" > /proc/sys/vm/dirty_background_ratio
;;
esac
- if [ $DO_REMOUNTS -eq 1 ]; then
+ if [ $DO_REMOUNTS -eq 1 ] ; then
cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do
# Reset commit and atime options to defaults.
case "$FST" in
echo "."
;;
*)
- echo "Usage: $0 {start|stop}"
+ echo "Usage: $0 {start|stop}" 2>&1
+ exit 1
;;
esac
exit 0
-
--------------------CONTROL SCRIPT END--------------------------------------------
case $status in
"on-line")
- echo "Setting HD spindown to 2 hours"
- /sbin/laptop-mode stop
+ echo "Setting HD spindown for AC mode."
+ /sbin/laptop_mode stop
/sbin/hdparm -S $ACAD_HD /dev/hda > /dev/null 2>&1
/sbin/hdparm -B 255 /dev/hda > /dev/null 2>&1
#echo -n $ACAD_CPU:$ACAD_THR > /proc/acpi/processor/CPU0/limit
exit 0
;;
"off-line")
- echo "Setting HD spindown to 20 seconds"
- /sbin/laptop-mode start
+ echo "Setting HD spindown for battery mode."
+ /sbin/laptop_mode start
/sbin/hdparm -S $BATT_HD /dev/hda > /dev/null 2>&1
/sbin/hdparm -B 1 /dev/hda > /dev/null 2>&1
#echo -n $BATT_CPU:$BATT_THR > /proc/acpi/processor/CPU0/limit
git://git.onelab.eu / linux-2.6.git / blobdiff