1 ===============================================
2 How to conserve battery power using laptop-mode
3 ===============================================
4
5 Document Author: Bart Samwel (bart@samwel.tk)
6
7 Date created: January 2, 2004
8
9 Last modified: December 06, 2004
10
11 Introduction
12 ------------
13
14 Laptop mode is used to minimize the time that the hard disk needs to be spun up,
15 to conserve battery power on laptops. It has been reported to cause significant
16 power savings.
17
18 .. Contents
19
20 * Introduction
21 * Installation
22 * Caveats
23 * The Details
24 * Tips & Tricks
25 * Control script
26 * ACPI integration
27 * Monitoring tool
28
29
30 Installation
31 ------------
32
33 To use laptop mode, you don't need to set any kernel configuration options
34 or anything. Simply install all the files included in this document, and
35 laptop mode will automatically be started when you're on battery. For
36 your convenience, a tarball containing an installer can be downloaded at:
37
38 http://www.samwel.tk/laptop_mode/laptop_mode/
39
40 To configure laptop mode, you need to edit the configuration file, which is
41 located in /etc/default/laptop-mode on Debian-based systems, or in
42 /etc/sysconfig/laptop-mode on other systems.
43
44 Unfortunately, automatic enabling of laptop mode does not work for
45 laptops that don't have ACPI. On those laptops, you need to start laptop
46 mode manually. To start laptop mode, run "laptop_mode start", and to
47 stop it, run "laptop_mode stop". (Note: The laptop mode tools package now
48 has experimental support for APM, you might want to try that first.)
49
50
51 Caveats
52 -------
53
54 * The downside of laptop mode is that you have a chance of losing up to 10
55 minutes of work. If you cannot afford this, don't use it! The supplied ACPI
56 scripts automatically turn off laptop mode when the battery almost runs out,
57 so that you won't lose any data at the end of your battery life.
58
59 * Most desktop hard drives have a very limited lifetime measured in spindown
60 cycles, typically about 50.000 times (it's usually listed on the spec sheet).
61 Check your drive's rating, and don't wear down your drive's lifetime if you
62 don't need to.
63
64 * If you mount some of your ext3/reiserfs filesystems with the -n option, then
65 the control script will not be able to remount them correctly. You must set
66 DO_REMOUNTS=0 in the control script, otherwise it will remount them with the
67 wrong options -- or it will fail because it cannot write to /etc/mtab.
68
69 * If you have your filesystems listed as type "auto" in fstab, like I did, then
70 the control script will not recognize them as filesystems that need remounting.
71 You must list the filesystems with their true type instead.
72
73 * It has been reported that some versions of the mutt mail client use file access
74 times to determine whether a folder contains new mail. If you use mutt and
75 experience this, you must disable the noatime remounting by setting the option
76 DO_REMOUNT_NOATIME to 0 in the configuration file.
77
78
79 The Details
80 -----------
81
82 Laptop mode is controlled by the knob /proc/sys/vm/laptop_mode. This knob is
83 present for all kernels that have the laptop mode patch, regardless of any
84 configuration options. When the knob is set, any physical disk I/O (that might
85 have caused the hard disk to spin up) causes Linux to flush all dirty blocks. The
86 result of this is that after a disk has spun down, it will not be spun up
87 anymore to write dirty blocks, because those blocks had already been written
88 immediately after the most recent read operation. The value of the laptop_mode
89 knob determines the time between the occurrence of disk I/O and when the flush
90 is triggered. A sensible value for the knob is 5 seconds. Setting the knob to
91 0 disables laptop mode.
92
93 To increase the effectiveness of the laptop_mode strategy, the laptop_mode
94 control script increases dirty_expire_centisecs and dirty_writeback_centisecs in
95 /proc/sys/vm to about 10 minutes (by default), which means that pages that are
96 dirtied are not forced to be written to disk as often. The control script also
97 changes the dirty background ratio, so that background writeback of dirty pages
98 is not done anymore. Combined with a higher commit value (also 10 minutes) for
99 ext3 or ReiserFS filesystems (also done automatically by the control script),
100 this results in concentration of disk activity in a small time interval which
101 occurs only once every 10 minutes, or whenever the disk is forced to spin up by
102 a cache miss. The disk can then be spun down in the periods of inactivity.
103
104
105 Configuration
106 -------------
107
108 The laptop mode configuration file is located in /etc/default/laptop-mode on
109 Debian-based systems, or in /etc/sysconfig/laptop-mode on other systems. It
110 contains the following options:
111
112 MAX_AGE:
113
114 Maximum time, in seconds, of hard drive spindown time that you are
115 comfortable with. Worst case, it's possible that you could lose this
116 amount of work if your battery fails while you're in laptop mode.
117
118 MINIMUM_BATTERY_MINUTES:
119
120 Automatically disable laptop mode if the remaining number of minutes of
121 battery power is less than this value. Default is 10 minutes.
122
123 AC_HD/BATT_HD:
124
125 The idle timeout that should be set on your hard drive when laptop mode
126 is active (BATT_HD) and when it is not active (AC_HD). The defaults are
127 20 seconds (value 4) for BATT_HD and 2 hours (value 244) for AC_HD. The
128 possible values are those listed in the manual page for "hdparm" for the
129 "-S" option.
130
131 HD:
132
133 The devices for which the spindown timeout should be adjusted by laptop mode.
134 Default is /dev/hda. If you specify multiple devices, separate them by a space.
135
136 READAHEAD:
137
138 Disk readahead, in 512-byte sectors, while laptop mode is active. A large
139 readahead can prevent disk accesses for things like executable pages (which are
140 loaded on demand while the application executes) and sequentially accessed data
141 (MP3s).
142
143 DO_REMOUNTS:
144
145 The control script automatically remounts any mounted journaled filesystems
146 with appropriate commit interval options. When this option is set to 0, this
147 feature is disabled.
148
149 DO_REMOUNT_NOATIME:
150
151 When remounting, should the filesystems be remounted with the noatime option?
152 Normally, this is set to "1" (enabled), but there may be programs that require
153 access time recording.
154
155 DIRTY_RATIO:
156
157 The percentage of memory that is allowed to contain "dirty" or unsaved data
158 before a writeback is forced, while laptop mode is active. Corresponds to
159 the /proc/sys/vm/dirty_ratio sysctl.
160
161 DIRTY_BACKGROUND_RATIO:
162
163 The percentage of memory that is allowed to contain "dirty" or unsaved data
164 after a forced writeback is done due to an exceeding of DIRTY_RATIO. Set
165 this nice and low. This corresponds to the /proc/sys/vm/dirty_background_ratio
166 sysctl.
167
168 Note that the behaviour of dirty_background_ratio is quite different
169 when laptop mode is active and when it isn't. When laptop mode is inactive,
170 dirty_background_ratio is the threshold percentage at which background writeouts
171 start taking place. When laptop mode is active, however, background writeouts
172 are disabled, and the dirty_background_ratio only determines how much writeback
173 is done when dirty_ratio is reached.
174
175 DO_CPU:
176
177 Enable CPU frequency scaling when in laptop mode. (Requires CPUFreq to be setup.
178 See Documentation/admin-guide/pm/cpufreq.rst for more info. Disabled by default.)
179
180 CPU_MAXFREQ:
181
182 When on battery, what is the maximum CPU speed that the system should use? Legal
183 values are "slowest" for the slowest speed that your CPU is able to operate at,
184 or a value listed in /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies.
185
186
187 Tips & Tricks
188 -------------
189
190 * Bartek Kania reports getting up to 50 minutes of extra battery life (on top
191 of his regular 3 to 3.5 hours) using a spindown time of 5 seconds (BATT_HD=1).
192
193 * You can spin down the disk while playing MP3, by setting disk readahead
194 to 8MB (READAHEAD=16384). Effectively, the disk will read a complete MP3 at
195 once, and will then spin down while the MP3 is playing. (Thanks to Bartek
196 Kania.)
197
198 * Drew Scott Daniels observed: "I don't know why, but when I decrease the number
199 of colours that my display uses it consumes less battery power. I've seen
200 this on powerbooks too. I hope that this is a piece of information that
201 might be useful to the Laptop Mode patch or its users."
202
203 * In syslog.conf, you can prefix entries with a dash `-` to omit syncing the
204 file after every logging. When you're using laptop-mode and your disk doesn't
205 spin down, this is a likely culprit.
206
207 * Richard Atterer observed that laptop mode does not work well with noflushd
208 (http://noflushd.sourceforge.net/), it seems that noflushd prevents laptop-mode
209 from doing its thing.
210
211 * If you're worried about your data, you might want to consider using a USB
212 memory stick or something like that as a "working area". (Be aware though
213 that flash memory can only handle a limited number of writes, and overuse
214 may wear out your memory stick pretty quickly. Do _not_ use journalling
215 filesystems on flash memory sticks.)
216
217
218 Configuration file for control and ACPI battery scripts
219 -------------------------------------------------------
220
221 This allows the tunables to be changed for the scripts via an external
222 configuration file
223
224 It should be installed as /etc/default/laptop-mode on Debian, and as
225 /etc/sysconfig/laptop-mode on Red Hat, SUSE, Mandrake, and other work-alikes.
226
227 Config file::
228
229 # Maximum time, in seconds, of hard drive spindown time that you are
230 # comfortable with. Worst case, it's possible that you could lose this
231 # amount of work if your battery fails you while in laptop mode.
232 #MAX_AGE=600
233
234 # Automatically disable laptop mode when the number of minutes of battery
235 # that you have left goes below this threshold.
236 MINIMUM_BATTERY_MINUTES=10
237
238 # Read-ahead, in 512-byte sectors. You can spin down the disk while playing MP3/OGG
239 # by setting the disk readahead to 8MB (READAHEAD=16384). Effectively, the disk
240 # will read a complete MP3 at once, and will then spin down while the MP3/OGG is
241 # playing.
242 #READAHEAD=4096
243
244 # Shall we remount journaled fs. with appropriate commit interval? (1=yes)
245 #DO_REMOUNTS=1
246
247 # And shall we add the "noatime" option to that as well? (1=yes)
248 #DO_REMOUNT_NOATIME=1
249
250 # Dirty synchronous ratio. At this percentage of dirty pages the process
251 # which
252 # calls write() does its own writeback
253 #DIRTY_RATIO=40
254
255 #
256 # Allowed dirty background ratio, in percent. Once DIRTY_RATIO has been
257 # exceeded, the kernel will wake flusher threads which will then reduce the
258 # amount of dirty memory to dirty_background_ratio. Set this nice and low,
259 # so once some writeout has commenced, we do a lot of it.
260 #
261 #DIRTY_BACKGROUND_RATIO=5
262
263 # kernel default dirty buffer age
264 #DEF_AGE=30
265 #DEF_UPDATE=5
266 #DEF_DIRTY_BACKGROUND_RATIO=10
267 #DEF_DIRTY_RATIO=40
268 #DEF_XFS_AGE_BUFFER=15
269 #DEF_XFS_SYNC_INTERVAL=30
270 #DEF_XFS_BUFD_INTERVAL=1
271
272 # This must be adjusted manually to the value of HZ in the running kernel
273 # on 2.4, until the XFS people change their 2.4 external interfaces to work in
274 # centisecs. This can be automated, but it's a work in progress that still
275 # needs# some fixes. On 2.6 kernels, XFS uses USER_HZ instead of HZ for
276 # external interfaces, and that is currently always set to 100. So you don't
277 # need to change this on 2.6.
278 #XFS_HZ=100
279
280 # Should the maximum CPU frequency be adjusted down while on battery?
281 # Requires CPUFreq to be setup.
282 # See Documentation/admin-guide/pm/cpufreq.rst for more info
283 #DO_CPU=0
284
285 # When on battery what is the maximum CPU speed that the system should
286 # use? Legal values are "slowest" for the slowest speed that your
287 # CPU is able to operate at, or a value listed in:
288 # /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
289 # Only applicable if DO_CPU=1.
290 #CPU_MAXFREQ=slowest
291
292 # Idle timeout for your hard drive (man hdparm for valid values, -S option)
293 # Default is 2 hours on AC (AC_HD=244) and 20 seconds for battery (BATT_HD=4).
294 #AC_HD=244
295 #BATT_HD=4
296
297 # The drives for which to adjust the idle timeout. Separate them by a space,
298 # e.g. HD="/dev/hda /dev/hdb".
299 #HD="/dev/hda"
300
301 # Set the spindown timeout on a hard drive?
302 #DO_HD=1
303
304
305 Control script
306 --------------
307
308 Please note that this control script works for the Linux 2.4 and 2.6 series (thanks
309 to Kiko Piris).
310
311 Control script::
312
313 #!/bin/bash
314
315 # start or stop laptop_mode, best run by a power management daemon when
316 # ac gets connected/disconnected from a laptop
317 #
318 # install as /sbin/laptop_mode
319 #
320 # Contributors to this script: Kiko Piris
321 # Bart Samwel
322 # Micha Feigin
323 # Andrew Morton
324 # Herve Eychenne
325 # Dax Kelson
326 #
327 # Original Linux 2.4 version by: Jens Axboe
328
329 #############################################################################
330
331 # Source config
332 if [ -f /etc/default/laptop-mode ] ; then
333 # Debian
334 . /etc/default/laptop-mode
335 elif [ -f /etc/sysconfig/laptop-mode ] ; then
336 # Others
337 . /etc/sysconfig/laptop-mode
338 fi
339
340 # Don't raise an error if the config file is incomplete
341 # set defaults instead:
342
343 # Maximum time, in seconds, of hard drive spindown time that you are
344 # comfortable with. Worst case, it's possible that you could lose this
345 # amount of work if your battery fails you while in laptop mode.
346 MAX_AGE=${MAX_AGE:-'600'}
347
348 # Read-ahead, in kilobytes
349 READAHEAD=${READAHEAD:-'4096'}
350
351 # Shall we remount journaled fs. with appropriate commit interval? (1=yes)
352 DO_REMOUNTS=${DO_REMOUNTS:-'1'}
353
354 # And shall we add the "noatime" option to that as well? (1=yes)
355 DO_REMOUNT_NOATIME=${DO_REMOUNT_NOATIME:-'1'}
356
357 # Shall we adjust the idle timeout on a hard drive?
358 DO_HD=${DO_HD:-'1'}
359
360 # Adjust idle timeout on which hard drive?
361 HD="${HD:-'/dev/hda'}"
362
363 # spindown time for HD (hdparm -S values)
364 AC_HD=${AC_HD:-'244'}
365 BATT_HD=${BATT_HD:-'4'}
366
367 # Dirty synchronous ratio. At this percentage of dirty pages the process which
368 # calls write() does its own writeback
369 DIRTY_RATIO=${DIRTY_RATIO:-'40'}
370
371 # cpu frequency scaling
372 # See Documentation/admin-guide/pm/cpufreq.rst for more info
373 DO_CPU=${CPU_MANAGE:-'0'}
374 CPU_MAXFREQ=${CPU_MAXFREQ:-'slowest'}
375
376 #
377 # Allowed dirty background ratio, in percent. Once DIRTY_RATIO has been
378 # exceeded, the kernel will wake flusher threads which will then reduce the
379 # amount of dirty memory to dirty_background_ratio. Set this nice and low,
380 # so once some writeout has commenced, we do a lot of it.
381 #
382 DIRTY_BACKGROUND_RATIO=${DIRTY_BACKGROUND_RATIO:-'5'}
383
384 # kernel default dirty buffer age
385 DEF_AGE=${DEF_AGE:-'30'}
386 DEF_UPDATE=${DEF_UPDATE:-'5'}
387 DEF_DIRTY_BACKGROUND_RATIO=${DEF_DIRTY_BACKGROUND_RATIO:-'10'}
388 DEF_DIRTY_RATIO=${DEF_DIRTY_RATIO:-'40'}
389 DEF_XFS_AGE_BUFFER=${DEF_XFS_AGE_BUFFER:-'15'}
390 DEF_XFS_SYNC_INTERVAL=${DEF_XFS_SYNC_INTERVAL:-'30'}
391 DEF_XFS_BUFD_INTERVAL=${DEF_XFS_BUFD_INTERVAL:-'1'}
392
393 # This must be adjusted manually to the value of HZ in the running kernel
394 # on 2.4, until the XFS people change their 2.4 external interfaces to work in
395 # centisecs. This can be automated, but it's a work in progress that still needs
396 # some fixes. On 2.6 kernels, XFS uses USER_HZ instead of HZ for external
397 # interfaces, and that is currently always set to 100. So you don't need to
398 # change this on 2.6.
399 XFS_HZ=${XFS_HZ:-'100'}
400
401 #############################################################################
402
403 KLEVEL="$(uname -r |
404 {
405 IFS='.' read a b c
406 echo $a.$b
407 }
408 )"
409 case "$KLEVEL" in
410 "2.4"|"2.6")
411 ;;
412 *)
413 echo "Unhandled kernel version: $KLEVEL ('uname -r' = '$(uname -r)')" >&2
414 exit 1
415 ;;
416 esac
417
418 if [ ! -e /proc/sys/vm/laptop_mode ] ; then
419 echo "Kernel is not patched with laptop_mode patch." >&2
420 exit 1
421 fi
422
423 if [ ! -w /proc/sys/vm/laptop_mode ] ; then
424 echo "You do not have enough privileges to enable laptop_mode." >&2
425 exit 1
426 fi
427
428 # Remove an option (the first parameter) of the form option=<number> from
429 # a mount options string (the rest of the parameters).
430 parse_mount_opts () {
431 OPT="$1"
432 shift
433 echo ",$*," | sed \
434 -e 's/,'"$OPT"'=[0-9]*,/,/g' \
435 -e 's/,,*/,/g' \
436 -e 's/^,//' \
437 -e 's/,$//'
438 }
439
440 # Remove an option (the first parameter) without any arguments from
441 # a mount option string (the rest of the parameters).
442 parse_nonumber_mount_opts () {
443 OPT="$1"
444 shift
445 echo ",$*," | sed \
446 -e 's/,'"$OPT"',/,/g' \
447 -e 's/,,*/,/g' \
448 -e 's/^,//' \
449 -e 's/,$//'
450 }
451
452 # Find out the state of a yes/no option (e.g. "atime"/"noatime") in
453 # fstab for a given filesystem, and use this state to replace the
454 # value of the option in another mount options string. The device
455 # is the first argument, the option name the second, and the default
456 # value the third. The remainder is the mount options string.
457 #
458 # Example:
459 # parse_yesno_opts_wfstab /dev/hda1 atime atime defaults,noatime
460 #
461 # If fstab contains, say, "rw" for this filesystem, then the result
462 # will be "defaults,atime".
463 parse_yesno_opts_wfstab () {
464 L_DEV="$1"
465 OPT="$2"
466 DEF_OPT="$3"
467 shift 3
468 L_OPTS="$*"
469 PARSEDOPTS1="$(parse_nonumber_mount_opts $OPT $L_OPTS)"
470 PARSEDOPTS1="$(parse_nonumber_mount_opts no$OPT $PARSEDOPTS1)"
471 # Watch for a default atime in fstab
472 FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)"
473 if echo "$FSTAB_OPTS" | grep "$OPT" > /dev/null ; then
474 # option specified in fstab: extract the value and use it
475 if echo "$FSTAB_OPTS" | grep "no$OPT" > /dev/null ; then
476 echo "$PARSEDOPTS1,no$OPT"
477 else
478 # no$OPT not found -- so we must have $OPT.
479 echo "$PARSEDOPTS1,$OPT"
480 fi
481 else
482 # option not specified in fstab -- choose the default.
483 echo "$PARSEDOPTS1,$DEF_OPT"
484 fi
485 }
486
487 # Find out the state of a numbered option (e.g. "commit=NNN") in
488 # fstab for a given filesystem, and use this state to replace the
489 # value of the option in another mount options string. The device
490 # is the first argument, and the option name the second. The
491 # remainder is the mount options string in which the replacement
492 # must be done.
493 #
494 # Example:
495 # parse_mount_opts_wfstab /dev/hda1 commit defaults,commit=7
496 #
497 # If fstab contains, say, "commit=3,rw" for this filesystem, then the
498 # result will be "rw,commit=3".
499 parse_mount_opts_wfstab () {
500 L_DEV="$1"
501 OPT="$2"
502 shift 2
503 L_OPTS="$*"
504 PARSEDOPTS1="$(parse_mount_opts $OPT $L_OPTS)"
505 # Watch for a default commit in fstab
506 FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)"
507 if echo "$FSTAB_OPTS" | grep "$OPT=" > /dev/null ; then
508 # option specified in fstab: extract the value, and use it
509 echo -n "$PARSEDOPTS1,$OPT="
510 echo ",$FSTAB_OPTS," | sed \
511 -e 's/.*,'"$OPT"'=//' \
512 -e 's/,.*//'
513 else
514 # option not specified in fstab: set it to 0
515 echo "$PARSEDOPTS1,$OPT=0"
516 fi
517 }
518
519 deduce_fstype () {
520 MP="$1"
521 # My root filesystem unfortunately has
522 # type "unknown" in /etc/mtab. If we encounter
523 # "unknown", we try to get the type from fstab.
524 cat /etc/fstab |
525 grep -v '^#' |
526 while read FSTAB_DEV FSTAB_MP FSTAB_FST FSTAB_OPTS FSTAB_DUMP FSTAB_DUMP ; do
527 if [ "$FSTAB_MP" = "$MP" ]; then
528 echo $FSTAB_FST
529 exit 0
530 fi
531 done
532 }
533
534 if [ $DO_REMOUNT_NOATIME -eq 1 ] ; then
535 NOATIME_OPT=",noatime"
536 fi
537
538 case "$1" in
539 start)
540 AGE=$((100*$MAX_AGE))
541 XFS_AGE=$(($XFS_HZ*$MAX_AGE))
542 echo -n "Starting laptop_mode"
543
544 if [ -d /proc/sys/vm/pagebuf ] ; then
545 # (For 2.4 and early 2.6.)
546 # This only needs to be set, not reset -- it is only used when
547 # laptop mode is enabled.
548 echo $XFS_AGE > /proc/sys/vm/pagebuf/lm_flush_age
549 echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval
550 elif [ -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
551 # (A couple of early 2.6 laptop mode patches had these.)
552 # The same goes for these.
553 echo $XFS_AGE > /proc/sys/fs/xfs/lm_age_buffer
554 echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval
555 elif [ -f /proc/sys/fs/xfs/age_buffer ] ; then
556 # (2.6.6)
557 # But not for these -- they are also used in normal
558 # operation.
559 echo $XFS_AGE > /proc/sys/fs/xfs/age_buffer
560 echo $XFS_AGE > /proc/sys/fs/xfs/sync_interval
561 elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then
562 # (2.6.7 upwards)
563 # And not for these either. These are in centisecs,
564 # not USER_HZ, so we have to use $AGE, not $XFS_AGE.
565 echo $AGE > /proc/sys/fs/xfs/age_buffer_centisecs
566 echo $AGE > /proc/sys/fs/xfs/xfssyncd_centisecs
567 echo 3000 > /proc/sys/fs/xfs/xfsbufd_centisecs
568 fi
569
570 case "$KLEVEL" in
571 "2.4")
572 echo 1 > /proc/sys/vm/laptop_mode
573 echo "30 500 0 0 $AGE $AGE 60 20 0" > /proc/sys/vm/bdflush
574 ;;
575 "2.6")
576 echo 5 > /proc/sys/vm/laptop_mode
577 echo "$AGE" > /proc/sys/vm/dirty_writeback_centisecs
578 echo "$AGE" > /proc/sys/vm/dirty_expire_centisecs
579 echo "$DIRTY_RATIO" > /proc/sys/vm/dirty_ratio
580 echo "$DIRTY_BACKGROUND_RATIO" > /proc/sys/vm/dirty_background_ratio
581 ;;
582 esac
583 if [ $DO_REMOUNTS -eq 1 ]; then
584 cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do
585 PARSEDOPTS="$(parse_mount_opts "$OPTS")"
586 if [ "$FST" = 'unknown' ]; then
587 FST=$(deduce_fstype $MP)
588 fi
589 case "$FST" in
590 "ext3"|"reiserfs")
591 PARSEDOPTS="$(parse_mount_opts commit "$OPTS")"
592 mount $DEV -t $FST $MP -o remount,$PARSEDOPTS,commit=$MAX_AGE$NOATIME_OPT
593 ;;
594 "xfs")
595 mount $DEV -t $FST $MP -o remount,$OPTS$NOATIME_OPT
596 ;;
597 esac
598 if [ -b $DEV ] ; then
599 blockdev --setra $(($READAHEAD * 2)) $DEV
600 fi
601 done
602 fi
603 if [ $DO_HD -eq 1 ] ; then
604 for THISHD in $HD ; do
605 /sbin/hdparm -S $BATT_HD $THISHD > /dev/null 2>&1
606 /sbin/hdparm -B 1 $THISHD > /dev/null 2>&1
607 done
608 fi
609 if [ $DO_CPU -eq 1 -a -e /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq ]; then
610 if [ $CPU_MAXFREQ = 'slowest' ]; then
611 CPU_MAXFREQ=`cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq`
612 fi
613 echo $CPU_MAXFREQ > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
614 fi
615 echo "."
616 ;;
617 stop)
618 U_AGE=$((100*$DEF_UPDATE))
619 B_AGE=$((100*$DEF_AGE))
620 echo -n "Stopping laptop_mode"
621 echo 0 > /proc/sys/vm/laptop_mode
622 if [ -f /proc/sys/fs/xfs/age_buffer -a ! -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
623 # These need to be restored, if there are no lm_*.
624 echo $(($XFS_HZ*$DEF_XFS_AGE_BUFFER)) > /proc/sys/fs/xfs/age_buffer
625 echo $(($XFS_HZ*$DEF_XFS_SYNC_INTERVAL)) > /proc/sys/fs/xfs/sync_interval
626 elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then
627 # These need to be restored as well.
628 echo $((100*$DEF_XFS_AGE_BUFFER)) > /proc/sys/fs/xfs/age_buffer_centisecs
629 echo $((100*$DEF_XFS_SYNC_INTERVAL)) > /proc/sys/fs/xfs/xfssyncd_centisecs
630 echo $((100*$DEF_XFS_BUFD_INTERVAL)) > /proc/sys/fs/xfs/xfsbufd_centisecs
631 fi
632 case "$KLEVEL" in
633 "2.4")
634 echo "30 500 0 0 $U_AGE $B_AGE 60 20 0" > /proc/sys/vm/bdflush
635 ;;
636 "2.6")
637 echo "$U_AGE" > /proc/sys/vm/dirty_writeback_centisecs
638 echo "$B_AGE" > /proc/sys/vm/dirty_expire_centisecs
639 echo "$DEF_DIRTY_RATIO" > /proc/sys/vm/dirty_ratio
640 echo "$DEF_DIRTY_BACKGROUND_RATIO" > /proc/sys/vm/dirty_background_ratio
641 ;;
642 esac
643 if [ $DO_REMOUNTS -eq 1 ] ; then
644 cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do
645 # Reset commit and atime options to defaults.
646 if [ "$FST" = 'unknown' ]; then
647 FST=$(deduce_fstype $MP)
648 fi
649 case "$FST" in
650 "ext3"|"reiserfs")
651 PARSEDOPTS="$(parse_mount_opts_wfstab $DEV commit $OPTS)"
652 PARSEDOPTS="$(parse_yesno_opts_wfstab $DEV atime atime $PARSEDOPTS)"
653 mount $DEV -t $FST $MP -o remount,$PARSEDOPTS
654 ;;
655 "xfs")
656 PARSEDOPTS="$(parse_yesno_opts_wfstab $DEV atime atime $OPTS)"
657 mount $DEV -t $FST $MP -o remount,$PARSEDOPTS
658 ;;
659 esac
660 if [ -b $DEV ] ; then
661 blockdev --setra 256 $DEV
662 fi
663 done
664 fi
665 if [ $DO_HD -eq 1 ] ; then
666 for THISHD in $HD ; do
667 /sbin/hdparm -S $AC_HD $THISHD > /dev/null 2>&1
668 /sbin/hdparm -B 255 $THISHD > /dev/null 2>&1
669 done
670 fi
671 if [ $DO_CPU -eq 1 -a -e /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq ]; then
672 echo `cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq` > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
673 fi
674 echo "."
675 ;;
676 *)
677 echo "Usage: $0 {start|stop}" 2>&1
678 exit 1
679 ;;
680
681 esac
682
683 exit 0
684
685
686 ACPI integration
687 ----------------
688
689 Dax Kelson submitted this so that the ACPI acpid daemon will
690 kick off the laptop_mode script and run hdparm. The part that
691 automatically disables laptop mode when the battery is low was
692 written by Jan Topinski.
693
694 /etc/acpi/events/ac_adapter::
695
696 event=ac_adapter
697 action=/etc/acpi/actions/ac.sh %e
698
699 /etc/acpi/events/battery::
700
701 event=battery.*
702 action=/etc/acpi/actions/battery.sh %e
703
704 /etc/acpi/actions/ac.sh::
705
706 #!/bin/bash
707
708 # ac on/offline event handler
709
710 status=`awk '/^state: / { print $2 }' /proc/acpi/ac_adapter/$2/state`
711
712 case $status in
713 "on-line")
714 /sbin/laptop_mode stop
715 exit 0
716 ;;
717 "off-line")
718 /sbin/laptop_mode start
719 exit 0
720 ;;
721 esac
722
723
724 /etc/acpi/actions/battery.sh::
725
726 #! /bin/bash
727
728 # Automatically disable laptop mode when the battery almost runs out.
729
730 BATT_INFO=/proc/acpi/battery/$2/state
731
732 if [[ -f /proc/sys/vm/laptop_mode ]]
733 then
734 LM=`cat /proc/sys/vm/laptop_mode`
735 if [[ $LM -gt 0 ]]
736 then
737 if [[ -f $BATT_INFO ]]
738 then
739 # Source the config file only now that we know we need
740 if [ -f /etc/default/laptop-mode ] ; then
741 # Debian
742 . /etc/default/laptop-mode
743 elif [ -f /etc/sysconfig/laptop-mode ] ; then
744 # Others
745 . /etc/sysconfig/laptop-mode
746 fi
747 MINIMUM_BATTERY_MINUTES=${MINIMUM_BATTERY_MINUTES:-'10'}
748
749 ACTION="`cat $BATT_INFO | grep charging | cut -c 26-`"
750 if [[ ACTION -eq "discharging" ]]
751 then
752 PRESENT_RATE=`cat $BATT_INFO | grep "present rate:" | sed "s/.* \([0-9][0-9]* \).*/\1/" `
753 REMAINING=`cat $BATT_INFO | grep "remaining capacity:" | sed "s/.* \([0-9][0-9]* \).*/\1/" `
754 fi
755 if (($REMAINING * 60 / $PRESENT_RATE < $MINIMUM_BATTERY_MINUTES))
756 then
757 /sbin/laptop_mode stop
758 fi
759 else
760 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."
761 fi
762 fi
763 fi
764
765
766 Monitoring tool
767 ---------------
768
769 Bartek Kania submitted this, it can be used to measure how much time your disk
770 spends spun up/down. See tools/laptop/dslm/dslm.c
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