0001 ===============================================
0002 How to conserve battery power using laptop-mode
0003 ===============================================
0004
0005 Document Author: Bart Samwel (bart@samwel.tk)
0006
0007 Date created: January 2, 2004
0008
0009 Last modified: December 06, 2004
0010
0011 Introduction
0012 ------------
0013
0014 Laptop mode is used to minimize the time that the hard disk needs to be spun up,
0015 to conserve battery power on laptops. It has been reported to cause significant
0016 power savings.
0017
0018 .. Contents
0019
0020 * Introduction
0021 * Installation
0022 * Caveats
0023 * The Details
0024 * Tips & Tricks
0025 * Control script
0026 * ACPI integration
0027 * Monitoring tool
0028
0029
0030 Installation
0031 ------------
0032
0033 To use laptop mode, you don't need to set any kernel configuration options
0034 or anything. Simply install all the files included in this document, and
0035 laptop mode will automatically be started when you're on battery. For
0036 your convenience, a tarball containing an installer can be downloaded at:
0037
0038 http://www.samwel.tk/laptop_mode/laptop_mode/
0039
0040 To configure laptop mode, you need to edit the configuration file, which is
0041 located in /etc/default/laptop-mode on Debian-based systems, or in
0042 /etc/sysconfig/laptop-mode on other systems.
0043
0044 Unfortunately, automatic enabling of laptop mode does not work for
0045 laptops that don't have ACPI. On those laptops, you need to start laptop
0046 mode manually. To start laptop mode, run "laptop_mode start", and to
0047 stop it, run "laptop_mode stop". (Note: The laptop mode tools package now
0048 has experimental support for APM, you might want to try that first.)
0049
0050
0051 Caveats
0052 -------
0053
0054 * The downside of laptop mode is that you have a chance of losing up to 10
0055 minutes of work. If you cannot afford this, don't use it! The supplied ACPI
0056 scripts automatically turn off laptop mode when the battery almost runs out,
0057 so that you won't lose any data at the end of your battery life.
0058
0059 * Most desktop hard drives have a very limited lifetime measured in spindown
0060 cycles, typically about 50.000 times (it's usually listed on the spec sheet).
0061 Check your drive's rating, and don't wear down your drive's lifetime if you
0062 don't need to.
0063
0064 * If you mount some of your ext3/reiserfs filesystems with the -n option, then
0065 the control script will not be able to remount them correctly. You must set
0066 DO_REMOUNTS=0 in the control script, otherwise it will remount them with the
0067 wrong options -- or it will fail because it cannot write to /etc/mtab.
0068
0069 * If you have your filesystems listed as type "auto" in fstab, like I did, then
0070 the control script will not recognize them as filesystems that need remounting.
0071 You must list the filesystems with their true type instead.
0072
0073 * It has been reported that some versions of the mutt mail client use file access
0074 times to determine whether a folder contains new mail. If you use mutt and
0075 experience this, you must disable the noatime remounting by setting the option
0076 DO_REMOUNT_NOATIME to 0 in the configuration file.
0077
0078
0079 The Details
0080 -----------
0081
0082 Laptop mode is controlled by the knob /proc/sys/vm/laptop_mode. This knob is
0083 present for all kernels that have the laptop mode patch, regardless of any
0084 configuration options. When the knob is set, any physical disk I/O (that might
0085 have caused the hard disk to spin up) causes Linux to flush all dirty blocks. The
0086 result of this is that after a disk has spun down, it will not be spun up
0087 anymore to write dirty blocks, because those blocks had already been written
0088 immediately after the most recent read operation. The value of the laptop_mode
0089 knob determines the time between the occurrence of disk I/O and when the flush
0090 is triggered. A sensible value for the knob is 5 seconds. Setting the knob to
0091 0 disables laptop mode.
0092
0093 To increase the effectiveness of the laptop_mode strategy, the laptop_mode
0094 control script increases dirty_expire_centisecs and dirty_writeback_centisecs in
0095 /proc/sys/vm to about 10 minutes (by default), which means that pages that are
0096 dirtied are not forced to be written to disk as often. The control script also
0097 changes the dirty background ratio, so that background writeback of dirty pages
0098 is not done anymore. Combined with a higher commit value (also 10 minutes) for
0099 ext3 or ReiserFS filesystems (also done automatically by the control script),
0100 this results in concentration of disk activity in a small time interval which
0101 occurs only once every 10 minutes, or whenever the disk is forced to spin up by
0102 a cache miss. The disk can then be spun down in the periods of inactivity.
0103
0104
0105 Configuration
0106 -------------
0107
0108 The laptop mode configuration file is located in /etc/default/laptop-mode on
0109 Debian-based systems, or in /etc/sysconfig/laptop-mode on other systems. It
0110 contains the following options:
0111
0112 MAX_AGE:
0113
0114 Maximum time, in seconds, of hard drive spindown time that you are
0115 comfortable with. Worst case, it's possible that you could lose this
0116 amount of work if your battery fails while you're in laptop mode.
0117
0118 MINIMUM_BATTERY_MINUTES:
0119
0120 Automatically disable laptop mode if the remaining number of minutes of
0121 battery power is less than this value. Default is 10 minutes.
0122
0123 AC_HD/BATT_HD:
0124
0125 The idle timeout that should be set on your hard drive when laptop mode
0126 is active (BATT_HD) and when it is not active (AC_HD). The defaults are
0127 20 seconds (value 4) for BATT_HD and 2 hours (value 244) for AC_HD. The
0128 possible values are those listed in the manual page for "hdparm" for the
0129 "-S" option.
0130
0131 HD:
0132
0133 The devices for which the spindown timeout should be adjusted by laptop mode.
0134 Default is /dev/hda. If you specify multiple devices, separate them by a space.
0135
0136 READAHEAD:
0137
0138 Disk readahead, in 512-byte sectors, while laptop mode is active. A large
0139 readahead can prevent disk accesses for things like executable pages (which are
0140 loaded on demand while the application executes) and sequentially accessed data
0141 (MP3s).
0142
0143 DO_REMOUNTS:
0144
0145 The control script automatically remounts any mounted journaled filesystems
0146 with appropriate commit interval options. When this option is set to 0, this
0147 feature is disabled.
0148
0149 DO_REMOUNT_NOATIME:
0150
0151 When remounting, should the filesystems be remounted with the noatime option?
0152 Normally, this is set to "1" (enabled), but there may be programs that require
0153 access time recording.
0154
0155 DIRTY_RATIO:
0156
0157 The percentage of memory that is allowed to contain "dirty" or unsaved data
0158 before a writeback is forced, while laptop mode is active. Corresponds to
0159 the /proc/sys/vm/dirty_ratio sysctl.
0160
0161 DIRTY_BACKGROUND_RATIO:
0162
0163 The percentage of memory that is allowed to contain "dirty" or unsaved data
0164 after a forced writeback is done due to an exceeding of DIRTY_RATIO. Set
0165 this nice and low. This corresponds to the /proc/sys/vm/dirty_background_ratio
0166 sysctl.
0167
0168 Note that the behaviour of dirty_background_ratio is quite different
0169 when laptop mode is active and when it isn't. When laptop mode is inactive,
0170 dirty_background_ratio is the threshold percentage at which background writeouts
0171 start taking place. When laptop mode is active, however, background writeouts
0172 are disabled, and the dirty_background_ratio only determines how much writeback
0173 is done when dirty_ratio is reached.
0174
0175 DO_CPU:
0176
0177 Enable CPU frequency scaling when in laptop mode. (Requires CPUFreq to be setup.
0178 See Documentation/admin-guide/pm/cpufreq.rst for more info. Disabled by default.)
0179
0180 CPU_MAXFREQ:
0181
0182 When on battery, what is the maximum CPU speed that the system should use? Legal
0183 values are "slowest" for the slowest speed that your CPU is able to operate at,
0184 or a value listed in /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies.
0185
0186
0187 Tips & Tricks
0188 -------------
0189
0190 * Bartek Kania reports getting up to 50 minutes of extra battery life (on top
0191 of his regular 3 to 3.5 hours) using a spindown time of 5 seconds (BATT_HD=1).
0192
0193 * You can spin down the disk while playing MP3, by setting disk readahead
0194 to 8MB (READAHEAD=16384). Effectively, the disk will read a complete MP3 at
0195 once, and will then spin down while the MP3 is playing. (Thanks to Bartek
0196 Kania.)
0197
0198 * Drew Scott Daniels observed: "I don't know why, but when I decrease the number
0199 of colours that my display uses it consumes less battery power. I've seen
0200 this on powerbooks too. I hope that this is a piece of information that
0201 might be useful to the Laptop Mode patch or its users."
0202
0203 * In syslog.conf, you can prefix entries with a dash `-` to omit syncing the
0204 file after every logging. When you're using laptop-mode and your disk doesn't
0205 spin down, this is a likely culprit.
0206
0207 * Richard Atterer observed that laptop mode does not work well with noflushd
0208 (http://noflushd.sourceforge.net/), it seems that noflushd prevents laptop-mode
0209 from doing its thing.
0210
0211 * If you're worried about your data, you might want to consider using a USB
0212 memory stick or something like that as a "working area". (Be aware though
0213 that flash memory can only handle a limited number of writes, and overuse
0214 may wear out your memory stick pretty quickly. Do _not_ use journalling
0215 filesystems on flash memory sticks.)
0216
0217
0218 Configuration file for control and ACPI battery scripts
0219 -------------------------------------------------------
0220
0221 This allows the tunables to be changed for the scripts via an external
0222 configuration file
0223
0224 It should be installed as /etc/default/laptop-mode on Debian, and as
0225 /etc/sysconfig/laptop-mode on Red Hat, SUSE, Mandrake, and other work-alikes.
0226
0227 Config file::
0228
0229 # Maximum time, in seconds, of hard drive spindown time that you are
0230 # comfortable with. Worst case, it's possible that you could lose this
0231 # amount of work if your battery fails you while in laptop mode.
0232 #MAX_AGE=600
0233
0234 # Automatically disable laptop mode when the number of minutes of battery
0235 # that you have left goes below this threshold.
0236 MINIMUM_BATTERY_MINUTES=10
0237
0238 # Read-ahead, in 512-byte sectors. You can spin down the disk while playing MP3/OGG
0239 # by setting the disk readahead to 8MB (READAHEAD=16384). Effectively, the disk
0240 # will read a complete MP3 at once, and will then spin down while the MP3/OGG is
0241 # playing.
0242 #READAHEAD=4096
0243
0244 # Shall we remount journaled fs. with appropriate commit interval? (1=yes)
0245 #DO_REMOUNTS=1
0246
0247 # And shall we add the "noatime" option to that as well? (1=yes)
0248 #DO_REMOUNT_NOATIME=1
0249
0250 # Dirty synchronous ratio. At this percentage of dirty pages the process
0251 # which
0252 # calls write() does its own writeback
0253 #DIRTY_RATIO=40
0254
0255 #
0256 # Allowed dirty background ratio, in percent. Once DIRTY_RATIO has been
0257 # exceeded, the kernel will wake flusher threads which will then reduce the
0258 # amount of dirty memory to dirty_background_ratio. Set this nice and low,
0259 # so once some writeout has commenced, we do a lot of it.
0260 #
0261 #DIRTY_BACKGROUND_RATIO=5
0262
0263 # kernel default dirty buffer age
0264 #DEF_AGE=30
0265 #DEF_UPDATE=5
0266 #DEF_DIRTY_BACKGROUND_RATIO=10
0267 #DEF_DIRTY_RATIO=40
0268 #DEF_XFS_AGE_BUFFER=15
0269 #DEF_XFS_SYNC_INTERVAL=30
0270 #DEF_XFS_BUFD_INTERVAL=1
0271
0272 # This must be adjusted manually to the value of HZ in the running kernel
0273 # on 2.4, until the XFS people change their 2.4 external interfaces to work in
0274 # centisecs. This can be automated, but it's a work in progress that still
0275 # needs# some fixes. On 2.6 kernels, XFS uses USER_HZ instead of HZ for
0276 # external interfaces, and that is currently always set to 100. So you don't
0277 # need to change this on 2.6.
0278 #XFS_HZ=100
0279
0280 # Should the maximum CPU frequency be adjusted down while on battery?
0281 # Requires CPUFreq to be setup.
0282 # See Documentation/admin-guide/pm/cpufreq.rst for more info
0283 #DO_CPU=0
0284
0285 # When on battery what is the maximum CPU speed that the system should
0286 # use? Legal values are "slowest" for the slowest speed that your
0287 # CPU is able to operate at, or a value listed in:
0288 # /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
0289 # Only applicable if DO_CPU=1.
0290 #CPU_MAXFREQ=slowest
0291
0292 # Idle timeout for your hard drive (man hdparm for valid values, -S option)
0293 # Default is 2 hours on AC (AC_HD=244) and 20 seconds for battery (BATT_HD=4).
0294 #AC_HD=244
0295 #BATT_HD=4
0296
0297 # The drives for which to adjust the idle timeout. Separate them by a space,
0298 # e.g. HD="/dev/hda /dev/hdb".
0299 #HD="/dev/hda"
0300
0301 # Set the spindown timeout on a hard drive?
0302 #DO_HD=1
0303
0304
0305 Control script
0306 --------------
0307
0308 Please note that this control script works for the Linux 2.4 and 2.6 series (thanks
0309 to Kiko Piris).
0310
0311 Control script::
0312
0313 #!/bin/bash
0314
0315 # start or stop laptop_mode, best run by a power management daemon when
0316 # ac gets connected/disconnected from a laptop
0317 #
0318 # install as /sbin/laptop_mode
0319 #
0320 # Contributors to this script: Kiko Piris
0321 # Bart Samwel
0322 # Micha Feigin
0323 # Andrew Morton
0324 # Herve Eychenne
0325 # Dax Kelson
0326 #
0327 # Original Linux 2.4 version by: Jens Axboe
0328
0329 #############################################################################
0330
0331 # Source config
0332 if [ -f /etc/default/laptop-mode ] ; then
0333 # Debian
0334 . /etc/default/laptop-mode
0335 elif [ -f /etc/sysconfig/laptop-mode ] ; then
0336 # Others
0337 . /etc/sysconfig/laptop-mode
0338 fi
0339
0340 # Don't raise an error if the config file is incomplete
0341 # set defaults instead:
0342
0343 # Maximum time, in seconds, of hard drive spindown time that you are
0344 # comfortable with. Worst case, it's possible that you could lose this
0345 # amount of work if your battery fails you while in laptop mode.
0346 MAX_AGE=${MAX_AGE:-'600'}
0347
0348 # Read-ahead, in kilobytes
0349 READAHEAD=${READAHEAD:-'4096'}
0350
0351 # Shall we remount journaled fs. with appropriate commit interval? (1=yes)
0352 DO_REMOUNTS=${DO_REMOUNTS:-'1'}
0353
0354 # And shall we add the "noatime" option to that as well? (1=yes)
0355 DO_REMOUNT_NOATIME=${DO_REMOUNT_NOATIME:-'1'}
0356
0357 # Shall we adjust the idle timeout on a hard drive?
0358 DO_HD=${DO_HD:-'1'}
0359
0360 # Adjust idle timeout on which hard drive?
0361 HD="${HD:-'/dev/hda'}"
0362
0363 # spindown time for HD (hdparm -S values)
0364 AC_HD=${AC_HD:-'244'}
0365 BATT_HD=${BATT_HD:-'4'}
0366
0367 # Dirty synchronous ratio. At this percentage of dirty pages the process which
0368 # calls write() does its own writeback
0369 DIRTY_RATIO=${DIRTY_RATIO:-'40'}
0370
0371 # cpu frequency scaling
0372 # See Documentation/admin-guide/pm/cpufreq.rst for more info
0373 DO_CPU=${CPU_MANAGE:-'0'}
0374 CPU_MAXFREQ=${CPU_MAXFREQ:-'slowest'}
0375
0376 #
0377 # Allowed dirty background ratio, in percent. Once DIRTY_RATIO has been
0378 # exceeded, the kernel will wake flusher threads which will then reduce the
0379 # amount of dirty memory to dirty_background_ratio. Set this nice and low,
0380 # so once some writeout has commenced, we do a lot of it.
0381 #
0382 DIRTY_BACKGROUND_RATIO=${DIRTY_BACKGROUND_RATIO:-'5'}
0383
0384 # kernel default dirty buffer age
0385 DEF_AGE=${DEF_AGE:-'30'}
0386 DEF_UPDATE=${DEF_UPDATE:-'5'}
0387 DEF_DIRTY_BACKGROUND_RATIO=${DEF_DIRTY_BACKGROUND_RATIO:-'10'}
0388 DEF_DIRTY_RATIO=${DEF_DIRTY_RATIO:-'40'}
0389 DEF_XFS_AGE_BUFFER=${DEF_XFS_AGE_BUFFER:-'15'}
0390 DEF_XFS_SYNC_INTERVAL=${DEF_XFS_SYNC_INTERVAL:-'30'}
0391 DEF_XFS_BUFD_INTERVAL=${DEF_XFS_BUFD_INTERVAL:-'1'}
0392
0393 # This must be adjusted manually to the value of HZ in the running kernel
0394 # on 2.4, until the XFS people change their 2.4 external interfaces to work in
0395 # centisecs. This can be automated, but it's a work in progress that still needs
0396 # some fixes. On 2.6 kernels, XFS uses USER_HZ instead of HZ for external
0397 # interfaces, and that is currently always set to 100. So you don't need to
0398 # change this on 2.6.
0399 XFS_HZ=${XFS_HZ:-'100'}
0400
0401 #############################################################################
0402
0403 KLEVEL="$(uname -r |
0404 {
0405 IFS='.' read a b c
0406 echo $a.$b
0407 }
0408 )"
0409 case "$KLEVEL" in
0410 "2.4"|"2.6")
0411 ;;
0412 *)
0413 echo "Unhandled kernel version: $KLEVEL ('uname -r' = '$(uname -r)')" >&2
0414 exit 1
0415 ;;
0416 esac
0417
0418 if [ ! -e /proc/sys/vm/laptop_mode ] ; then
0419 echo "Kernel is not patched with laptop_mode patch." >&2
0420 exit 1
0421 fi
0422
0423 if [ ! -w /proc/sys/vm/laptop_mode ] ; then
0424 echo "You do not have enough privileges to enable laptop_mode." >&2
0425 exit 1
0426 fi
0427
0428 # Remove an option (the first parameter) of the form option=<number> from
0429 # a mount options string (the rest of the parameters).
0430 parse_mount_opts () {
0431 OPT="$1"
0432 shift
0433 echo ",$*," | sed \
0434 -e 's/,'"$OPT"'=[0-9]*,/,/g' \
0435 -e 's/,,*/,/g' \
0436 -e 's/^,//' \
0437 -e 's/,$//'
0438 }
0439
0440 # Remove an option (the first parameter) without any arguments from
0441 # a mount option string (the rest of the parameters).
0442 parse_nonumber_mount_opts () {
0443 OPT="$1"
0444 shift
0445 echo ",$*," | sed \
0446 -e 's/,'"$OPT"',/,/g' \
0447 -e 's/,,*/,/g' \
0448 -e 's/^,//' \
0449 -e 's/,$//'
0450 }
0451
0452 # Find out the state of a yes/no option (e.g. "atime"/"noatime") in
0453 # fstab for a given filesystem, and use this state to replace the
0454 # value of the option in another mount options string. The device
0455 # is the first argument, the option name the second, and the default
0456 # value the third. The remainder is the mount options string.
0457 #
0458 # Example:
0459 # parse_yesno_opts_wfstab /dev/hda1 atime atime defaults,noatime
0460 #
0461 # If fstab contains, say, "rw" for this filesystem, then the result
0462 # will be "defaults,atime".
0463 parse_yesno_opts_wfstab () {
0464 L_DEV="$1"
0465 OPT="$2"
0466 DEF_OPT="$3"
0467 shift 3
0468 L_OPTS="$*"
0469 PARSEDOPTS1="$(parse_nonumber_mount_opts $OPT $L_OPTS)"
0470 PARSEDOPTS1="$(parse_nonumber_mount_opts no$OPT $PARSEDOPTS1)"
0471 # Watch for a default atime in fstab
0472 FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)"
0473 if echo "$FSTAB_OPTS" | grep "$OPT" > /dev/null ; then
0474 # option specified in fstab: extract the value and use it
0475 if echo "$FSTAB_OPTS" | grep "no$OPT" > /dev/null ; then
0476 echo "$PARSEDOPTS1,no$OPT"
0477 else
0478 # no$OPT not found -- so we must have $OPT.
0479 echo "$PARSEDOPTS1,$OPT"
0480 fi
0481 else
0482 # option not specified in fstab -- choose the default.
0483 echo "$PARSEDOPTS1,$DEF_OPT"
0484 fi
0485 }
0486
0487 # Find out the state of a numbered option (e.g. "commit=NNN") in
0488 # fstab for a given filesystem, and use this state to replace the
0489 # value of the option in another mount options string. The device
0490 # is the first argument, and the option name the second. The
0491 # remainder is the mount options string in which the replacement
0492 # must be done.
0493 #
0494 # Example:
0495 # parse_mount_opts_wfstab /dev/hda1 commit defaults,commit=7
0496 #
0497 # If fstab contains, say, "commit=3,rw" for this filesystem, then the
0498 # result will be "rw,commit=3".
0499 parse_mount_opts_wfstab () {
0500 L_DEV="$1"
0501 OPT="$2"
0502 shift 2
0503 L_OPTS="$*"
0504 PARSEDOPTS1="$(parse_mount_opts $OPT $L_OPTS)"
0505 # Watch for a default commit in fstab
0506 FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)"
0507 if echo "$FSTAB_OPTS" | grep "$OPT=" > /dev/null ; then
0508 # option specified in fstab: extract the value, and use it
0509 echo -n "$PARSEDOPTS1,$OPT="
0510 echo ",$FSTAB_OPTS," | sed \
0511 -e 's/.*,'"$OPT"'=//' \
0512 -e 's/,.*//'
0513 else
0514 # option not specified in fstab: set it to 0
0515 echo "$PARSEDOPTS1,$OPT=0"
0516 fi
0517 }
0518
0519 deduce_fstype () {
0520 MP="$1"
0521 # My root filesystem unfortunately has
0522 # type "unknown" in /etc/mtab. If we encounter
0523 # "unknown", we try to get the type from fstab.
0524 cat /etc/fstab |
0525 grep -v '^#' |
0526 while read FSTAB_DEV FSTAB_MP FSTAB_FST FSTAB_OPTS FSTAB_DUMP FSTAB_DUMP ; do
0527 if [ "$FSTAB_MP" = "$MP" ]; then
0528 echo $FSTAB_FST
0529 exit 0
0530 fi
0531 done
0532 }
0533
0534 if [ $DO_REMOUNT_NOATIME -eq 1 ] ; then
0535 NOATIME_OPT=",noatime"
0536 fi
0537
0538 case "$1" in
0539 start)
0540 AGE=$((100*$MAX_AGE))
0541 XFS_AGE=$(($XFS_HZ*$MAX_AGE))
0542 echo -n "Starting laptop_mode"
0543
0544 if [ -d /proc/sys/vm/pagebuf ] ; then
0545 # (For 2.4 and early 2.6.)
0546 # This only needs to be set, not reset -- it is only used when
0547 # laptop mode is enabled.
0548 echo $XFS_AGE > /proc/sys/vm/pagebuf/lm_flush_age
0549 echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval
0550 elif [ -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
0551 # (A couple of early 2.6 laptop mode patches had these.)
0552 # The same goes for these.
0553 echo $XFS_AGE > /proc/sys/fs/xfs/lm_age_buffer
0554 echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval
0555 elif [ -f /proc/sys/fs/xfs/age_buffer ] ; then
0556 # (2.6.6)
0557 # But not for these -- they are also used in normal
0558 # operation.
0559 echo $XFS_AGE > /proc/sys/fs/xfs/age_buffer
0560 echo $XFS_AGE > /proc/sys/fs/xfs/sync_interval
0561 elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then
0562 # (2.6.7 upwards)
0563 # And not for these either. These are in centisecs,
0564 # not USER_HZ, so we have to use $AGE, not $XFS_AGE.
0565 echo $AGE > /proc/sys/fs/xfs/age_buffer_centisecs
0566 echo $AGE > /proc/sys/fs/xfs/xfssyncd_centisecs
0567 echo 3000 > /proc/sys/fs/xfs/xfsbufd_centisecs
0568 fi
0569
0570 case "$KLEVEL" in
0571 "2.4")
0572 echo 1 > /proc/sys/vm/laptop_mode
0573 echo "30 500 0 0 $AGE $AGE 60 20 0" > /proc/sys/vm/bdflush
0574 ;;
0575 "2.6")
0576 echo 5 > /proc/sys/vm/laptop_mode
0577 echo "$AGE" > /proc/sys/vm/dirty_writeback_centisecs
0578 echo "$AGE" > /proc/sys/vm/dirty_expire_centisecs
0579 echo "$DIRTY_RATIO" > /proc/sys/vm/dirty_ratio
0580 echo "$DIRTY_BACKGROUND_RATIO" > /proc/sys/vm/dirty_background_ratio
0581 ;;
0582 esac
0583 if [ $DO_REMOUNTS -eq 1 ]; then
0584 cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do
0585 PARSEDOPTS="$(parse_mount_opts "$OPTS")"
0586 if [ "$FST" = 'unknown' ]; then
0587 FST=$(deduce_fstype $MP)
0588 fi
0589 case "$FST" in
0590 "ext3"|"reiserfs")
0591 PARSEDOPTS="$(parse_mount_opts commit "$OPTS")"
0592 mount $DEV -t $FST $MP -o remount,$PARSEDOPTS,commit=$MAX_AGE$NOATIME_OPT
0593 ;;
0594 "xfs")
0595 mount $DEV -t $FST $MP -o remount,$OPTS$NOATIME_OPT
0596 ;;
0597 esac
0598 if [ -b $DEV ] ; then
0599 blockdev --setra $(($READAHEAD * 2)) $DEV
0600 fi
0601 done
0602 fi
0603 if [ $DO_HD -eq 1 ] ; then
0604 for THISHD in $HD ; do
0605 /sbin/hdparm -S $BATT_HD $THISHD > /dev/null 2>&1
0606 /sbin/hdparm -B 1 $THISHD > /dev/null 2>&1
0607 done
0608 fi
0609 if [ $DO_CPU -eq 1 -a -e /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq ]; then
0610 if [ $CPU_MAXFREQ = 'slowest' ]; then
0611 CPU_MAXFREQ=`cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq`
0612 fi
0613 echo $CPU_MAXFREQ > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
0614 fi
0615 echo "."
0616 ;;
0617 stop)
0618 U_AGE=$((100*$DEF_UPDATE))
0619 B_AGE=$((100*$DEF_AGE))
0620 echo -n "Stopping laptop_mode"
0621 echo 0 > /proc/sys/vm/laptop_mode
0622 if [ -f /proc/sys/fs/xfs/age_buffer -a ! -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
0623 # These need to be restored, if there are no lm_*.
0624 echo $(($XFS_HZ*$DEF_XFS_AGE_BUFFER)) > /proc/sys/fs/xfs/age_buffer
0625 echo $(($XFS_HZ*$DEF_XFS_SYNC_INTERVAL)) > /proc/sys/fs/xfs/sync_interval
0626 elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then
0627 # These need to be restored as well.
0628 echo $((100*$DEF_XFS_AGE_BUFFER)) > /proc/sys/fs/xfs/age_buffer_centisecs
0629 echo $((100*$DEF_XFS_SYNC_INTERVAL)) > /proc/sys/fs/xfs/xfssyncd_centisecs
0630 echo $((100*$DEF_XFS_BUFD_INTERVAL)) > /proc/sys/fs/xfs/xfsbufd_centisecs
0631 fi
0632 case "$KLEVEL" in
0633 "2.4")
0634 echo "30 500 0 0 $U_AGE $B_AGE 60 20 0" > /proc/sys/vm/bdflush
0635 ;;
0636 "2.6")
0637 echo "$U_AGE" > /proc/sys/vm/dirty_writeback_centisecs
0638 echo "$B_AGE" > /proc/sys/vm/dirty_expire_centisecs
0639 echo "$DEF_DIRTY_RATIO" > /proc/sys/vm/dirty_ratio
0640 echo "$DEF_DIRTY_BACKGROUND_RATIO" > /proc/sys/vm/dirty_background_ratio
0641 ;;
0642 esac
0643 if [ $DO_REMOUNTS -eq 1 ] ; then
0644 cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do
0645 # Reset commit and atime options to defaults.
0646 if [ "$FST" = 'unknown' ]; then
0647 FST=$(deduce_fstype $MP)
0648 fi
0649 case "$FST" in
0650 "ext3"|"reiserfs")
0651 PARSEDOPTS="$(parse_mount_opts_wfstab $DEV commit $OPTS)"
0652 PARSEDOPTS="$(parse_yesno_opts_wfstab $DEV atime atime $PARSEDOPTS)"
0653 mount $DEV -t $FST $MP -o remount,$PARSEDOPTS
0654 ;;
0655 "xfs")
0656 PARSEDOPTS="$(parse_yesno_opts_wfstab $DEV atime atime $OPTS)"
0657 mount $DEV -t $FST $MP -o remount,$PARSEDOPTS
0658 ;;
0659 esac
0660 if [ -b $DEV ] ; then
0661 blockdev --setra 256 $DEV
0662 fi
0663 done
0664 fi
0665 if [ $DO_HD -eq 1 ] ; then
0666 for THISHD in $HD ; do
0667 /sbin/hdparm -S $AC_HD $THISHD > /dev/null 2>&1
0668 /sbin/hdparm -B 255 $THISHD > /dev/null 2>&1
0669 done
0670 fi
0671 if [ $DO_CPU -eq 1 -a -e /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq ]; then
0672 echo `cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq` > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
0673 fi
0674 echo "."
0675 ;;
0676 *)
0677 echo "Usage: $0 {start|stop}" 2>&1
0678 exit 1
0679 ;;
0680
0681 esac
0682
0683 exit 0
0684
0685
0686 ACPI integration
0687 ----------------
0688
0689 Dax Kelson submitted this so that the ACPI acpid daemon will
0690 kick off the laptop_mode script and run hdparm. The part that
0691 automatically disables laptop mode when the battery is low was
0692 written by Jan Topinski.
0693
0694 /etc/acpi/events/ac_adapter::
0695
0696 event=ac_adapter
0697 action=/etc/acpi/actions/ac.sh %e
0698
0699 /etc/acpi/events/battery::
0700
0701 event=battery.*
0702 action=/etc/acpi/actions/battery.sh %e
0703
0704 /etc/acpi/actions/ac.sh::
0705
0706 #!/bin/bash
0707
0708 # ac on/offline event handler
0709
0710 status=`awk '/^state: / { print $2 }' /proc/acpi/ac_adapter/$2/state`
0711
0712 case $status in
0713 "on-line")
0714 /sbin/laptop_mode stop
0715 exit 0
0716 ;;
0717 "off-line")
0718 /sbin/laptop_mode start
0719 exit 0
0720 ;;
0721 esac
0722
0723
0724 /etc/acpi/actions/battery.sh::
0725
0726 #! /bin/bash
0727
0728 # Automatically disable laptop mode when the battery almost runs out.
0729
0730 BATT_INFO=/proc/acpi/battery/$2/state
0731
0732 if [[ -f /proc/sys/vm/laptop_mode ]]
0733 then
0734 LM=`cat /proc/sys/vm/laptop_mode`
0735 if [[ $LM -gt 0 ]]
0736 then
0737 if [[ -f $BATT_INFO ]]
0738 then
0739 # Source the config file only now that we know we need
0740 if [ -f /etc/default/laptop-mode ] ; then
0741 # Debian
0742 . /etc/default/laptop-mode
0743 elif [ -f /etc/sysconfig/laptop-mode ] ; then
0744 # Others
0745 . /etc/sysconfig/laptop-mode
0746 fi
0747 MINIMUM_BATTERY_MINUTES=${MINIMUM_BATTERY_MINUTES:-'10'}
0748
0749 ACTION="`cat $BATT_INFO | grep charging | cut -c 26-`"
0750 if [[ ACTION -eq "discharging" ]]
0751 then
0752 PRESENT_RATE=`cat $BATT_INFO | grep "present rate:" | sed "s/.* \([0-9][0-9]* \).*/\1/" `
0753 REMAINING=`cat $BATT_INFO | grep "remaining capacity:" | sed "s/.* \([0-9][0-9]* \).*/\1/" `
0754 fi
0755 if (($REMAINING * 60 / $PRESENT_RATE < $MINIMUM_BATTERY_MINUTES))
0756 then
0757 /sbin/laptop_mode stop
0758 fi
0759 else
0760 logger -p daemon.warning "You are using laptop mode and your battery interface $BATT_INFO is missing. This may lead to loss of data when the battery runs out. Check kernel ACPI support and /proc/acpi/battery folder, and edit /etc/acpi/battery.sh to set BATT_INFO to the correct path."
0761 fi
0762 fi
0763 fi
0764
0765
0766 Monitoring tool
0767 ---------------
0768
0769 Bartek Kania submitted this, it can be used to measure how much time your disk
0770 spends spun up/down. See tools/laptop/dslm/dslm.c
