1=============================================== 2How to conserve battery power using laptop-mode 3=============================================== 4 5Document Author: Bart Samwel (bart@samwel.tk) 6 7Date created: January 2, 2004 8 9Last modified: December 06, 2004 10 11Introduction 12------------ 13 14Laptop mode is used to minimize the time that the hard disk needs to be spun up, 15to conserve battery power on laptops. It has been reported to cause significant 16power 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 30Installation 31------------ 32 33To use laptop mode, you don't need to set any kernel configuration options 34or anything. Simply install all the files included in this document, and 35laptop mode will automatically be started when you're on battery. For 36your convenience, a tarball containing an installer can be downloaded at: 37 38 http://www.samwel.tk/laptop_mode/laptop_mode/ 39 40To configure laptop mode, you need to edit the configuration file, which is 41located in /etc/default/laptop-mode on Debian-based systems, or in 42/etc/sysconfig/laptop-mode on other systems. 43 44Unfortunately, automatic enabling of laptop mode does not work for 45laptops that don't have ACPI. On those laptops, you need to start laptop 46mode manually. To start laptop mode, run "laptop_mode start", and to 47stop it, run "laptop_mode stop". (Note: The laptop mode tools package now 48has experimental support for APM, you might want to try that first.) 49 50 51Caveats 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 79The Details 80----------- 81 82Laptop mode is controlled by the knob /proc/sys/vm/laptop_mode. This knob is 83present for all kernels that have the laptop mode patch, regardless of any 84configuration options. When the knob is set, any physical disk I/O (that might 85have caused the hard disk to spin up) causes Linux to flush all dirty blocks. The 86result of this is that after a disk has spun down, it will not be spun up 87anymore to write dirty blocks, because those blocks had already been written 88immediately after the most recent read operation. The value of the laptop_mode 89knob determines the time between the occurrence of disk I/O and when the flush 90is triggered. A sensible value for the knob is 5 seconds. Setting the knob to 910 disables laptop mode. 92 93To increase the effectiveness of the laptop_mode strategy, the laptop_mode 94control 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 96dirtied are not forced to be written to disk as often. The control script also 97changes the dirty background ratio, so that background writeback of dirty pages 98is not done anymore. Combined with a higher commit value (also 10 minutes) for 99ext3 or ReiserFS filesystems (also done automatically by the control script), 100this results in concentration of disk activity in a small time interval which 101occurs only once every 10 minutes, or whenever the disk is forced to spin up by 102a cache miss. The disk can then be spun down in the periods of inactivity. 103 104If you want to find out which process caused the disk to spin up, you can 105gather information by setting the flag /proc/sys/vm/block_dump. When this flag 106is set, Linux reports all disk read and write operations that take place, and 107all block dirtyings done to files. This makes it possible to debug why a disk 108needs to spin up, and to increase battery life even more. The output of 109block_dump is written to the kernel output, and it can be retrieved using 110"dmesg". When you use block_dump and your kernel logging level also includes 111kernel debugging messages, you probably want to turn off klogd, otherwise 112the output of block_dump will be logged, causing disk activity that is not 113normally there. 114 115 116Configuration 117------------- 118 119The laptop mode configuration file is located in /etc/default/laptop-mode on 120Debian-based systems, or in /etc/sysconfig/laptop-mode on other systems. It 121contains the following options: 122 123MAX_AGE: 124 125Maximum time, in seconds, of hard drive spindown time that you are 126comfortable with. Worst case, it's possible that you could lose this 127amount of work if your battery fails while you're in laptop mode. 128 129MINIMUM_BATTERY_MINUTES: 130 131Automatically disable laptop mode if the remaining number of minutes of 132battery power is less than this value. Default is 10 minutes. 133 134AC_HD/BATT_HD: 135 136The idle timeout that should be set on your hard drive when laptop mode 137is active (BATT_HD) and when it is not active (AC_HD). The defaults are 13820 seconds (value 4) for BATT_HD and 2 hours (value 244) for AC_HD. The 139possible values are those listed in the manual page for "hdparm" for the 140"-S" option. 141 142HD: 143 144The devices for which the spindown timeout should be adjusted by laptop mode. 145Default is /dev/hda. If you specify multiple devices, separate them by a space. 146 147READAHEAD: 148 149Disk readahead, in 512-byte sectors, while laptop mode is active. A large 150readahead can prevent disk accesses for things like executable pages (which are 151loaded on demand while the application executes) and sequentially accessed data 152(MP3s). 153 154DO_REMOUNTS: 155 156The control script automatically remounts any mounted journaled filesystems 157with appropriate commit interval options. When this option is set to 0, this 158feature is disabled. 159 160DO_REMOUNT_NOATIME: 161 162When remounting, should the filesystems be remounted with the noatime option? 163Normally, this is set to "1" (enabled), but there may be programs that require 164access time recording. 165 166DIRTY_RATIO: 167 168The percentage of memory that is allowed to contain "dirty" or unsaved data 169before a writeback is forced, while laptop mode is active. Corresponds to 170the /proc/sys/vm/dirty_ratio sysctl. 171 172DIRTY_BACKGROUND_RATIO: 173 174The percentage of memory that is allowed to contain "dirty" or unsaved data 175after a forced writeback is done due to an exceeding of DIRTY_RATIO. Set 176this nice and low. This corresponds to the /proc/sys/vm/dirty_background_ratio 177sysctl. 178 179Note that the behaviour of dirty_background_ratio is quite different 180when laptop mode is active and when it isn't. When laptop mode is inactive, 181dirty_background_ratio is the threshold percentage at which background writeouts 182start taking place. When laptop mode is active, however, background writeouts 183are disabled, and the dirty_background_ratio only determines how much writeback 184is done when dirty_ratio is reached. 185 186DO_CPU: 187 188Enable CPU frequency scaling when in laptop mode. (Requires CPUFreq to be setup. 189See Documentation/admin-guide/pm/cpufreq.rst for more info. Disabled by default.) 190 191CPU_MAXFREQ: 192 193When on battery, what is the maximum CPU speed that the system should use? Legal 194values are "slowest" for the slowest speed that your CPU is able to operate at, 195or a value listed in /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies. 196 197 198Tips & Tricks 199------------- 200 201* Bartek Kania reports getting up to 50 minutes of extra battery life (on top 202 of his regular 3 to 3.5 hours) using a spindown time of 5 seconds (BATT_HD=1). 203 204* You can spin down the disk while playing MP3, by setting disk readahead 205 to 8MB (READAHEAD=16384). Effectively, the disk will read a complete MP3 at 206 once, and will then spin down while the MP3 is playing. (Thanks to Bartek 207 Kania.) 208 209* Drew Scott Daniels observed: "I don't know why, but when I decrease the number 210 of colours that my display uses it consumes less battery power. I've seen 211 this on powerbooks too. I hope that this is a piece of information that 212 might be useful to the Laptop Mode patch or its users." 213 214* In syslog.conf, you can prefix entries with a dash `-` to omit syncing the 215 file after every logging. When you're using laptop-mode and your disk doesn't 216 spin down, this is a likely culprit. 217 218* Richard Atterer observed that laptop mode does not work well with noflushd 219 (http://noflushd.sourceforge.net/), it seems that noflushd prevents laptop-mode 220 from doing its thing. 221 222* If you're worried about your data, you might want to consider using a USB 223 memory stick or something like that as a "working area". (Be aware though 224 that flash memory can only handle a limited number of writes, and overuse 225 may wear out your memory stick pretty quickly. Do _not_ use journalling 226 filesystems on flash memory sticks.) 227 228 229Configuration file for control and ACPI battery scripts 230------------------------------------------------------- 231 232This allows the tunables to be changed for the scripts via an external 233configuration file 234 235It should be installed as /etc/default/laptop-mode on Debian, and as 236/etc/sysconfig/laptop-mode on Red Hat, SUSE, Mandrake, and other work-alikes. 237 238Config file:: 239 240 # Maximum time, in seconds, of hard drive spindown time that you are 241 # comfortable with. Worst case, it's possible that you could lose this 242 # amount of work if your battery fails you while in laptop mode. 243 #MAX_AGE=600 244 245 # Automatically disable laptop mode when the number of minutes of battery 246 # that you have left goes below this threshold. 247 MINIMUM_BATTERY_MINUTES=10 248 249 # Read-ahead, in 512-byte sectors. You can spin down the disk while playing MP3/OGG 250 # by setting the disk readahead to 8MB (READAHEAD=16384). Effectively, the disk 251 # will read a complete MP3 at once, and will then spin down while the MP3/OGG is 252 # playing. 253 #READAHEAD=4096 254 255 # Shall we remount journaled fs. with appropriate commit interval? (1=yes) 256 #DO_REMOUNTS=1 257 258 # And shall we add the "noatime" option to that as well? (1=yes) 259 #DO_REMOUNT_NOATIME=1 260 261 # Dirty synchronous ratio. At this percentage of dirty pages the process 262 # which 263 # calls write() does its own writeback 264 #DIRTY_RATIO=40 265 266 # 267 # Allowed dirty background ratio, in percent. Once DIRTY_RATIO has been 268 # exceeded, the kernel will wake flusher threads which will then reduce the 269 # amount of dirty memory to dirty_background_ratio. Set this nice and low, 270 # so once some writeout has commenced, we do a lot of it. 271 # 272 #DIRTY_BACKGROUND_RATIO=5 273 274 # kernel default dirty buffer age 275 #DEF_AGE=30 276 #DEF_UPDATE=5 277 #DEF_DIRTY_BACKGROUND_RATIO=10 278 #DEF_DIRTY_RATIO=40 279 #DEF_XFS_AGE_BUFFER=15 280 #DEF_XFS_SYNC_INTERVAL=30 281 #DEF_XFS_BUFD_INTERVAL=1 282 283 # This must be adjusted manually to the value of HZ in the running kernel 284 # on 2.4, until the XFS people change their 2.4 external interfaces to work in 285 # centisecs. This can be automated, but it's a work in progress that still 286 # needs# some fixes. On 2.6 kernels, XFS uses USER_HZ instead of HZ for 287 # external interfaces, and that is currently always set to 100. So you don't 288 # need to change this on 2.6. 289 #XFS_HZ=100 290 291 # Should the maximum CPU frequency be adjusted down while on battery? 292 # Requires CPUFreq to be setup. 293 # See Documentation/admin-guide/pm/cpufreq.rst for more info 294 #DO_CPU=0 295 296 # When on battery what is the maximum CPU speed that the system should 297 # use? Legal values are "slowest" for the slowest speed that your 298 # CPU is able to operate at, or a value listed in: 299 # /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies 300 # Only applicable if DO_CPU=1. 301 #CPU_MAXFREQ=slowest 302 303 # Idle timeout for your hard drive (man hdparm for valid values, -S option) 304 # Default is 2 hours on AC (AC_HD=244) and 20 seconds for battery (BATT_HD=4). 305 #AC_HD=244 306 #BATT_HD=4 307 308 # The drives for which to adjust the idle timeout. Separate them by a space, 309 # e.g. HD="/dev/hda /dev/hdb". 310 #HD="/dev/hda" 311 312 # Set the spindown timeout on a hard drive? 313 #DO_HD=1 314 315 316Control script 317-------------- 318 319Please note that this control script works for the Linux 2.4 and 2.6 series (thanks 320to Kiko Piris). 321 322Control script:: 323 324 #!/bin/bash 325 326 # start or stop laptop_mode, best run by a power management daemon when 327 # ac gets connected/disconnected from a laptop 328 # 329 # install as /sbin/laptop_mode 330 # 331 # Contributors to this script: Kiko Piris 332 # Bart Samwel 333 # Micha Feigin 334 # Andrew Morton 335 # Herve Eychenne 336 # Dax Kelson 337 # 338 # Original Linux 2.4 version by: Jens Axboe 339 340 ############################################################################# 341 342 # Source config 343 if [ -f /etc/default/laptop-mode ] ; then 344 # Debian 345 . /etc/default/laptop-mode 346 elif [ -f /etc/sysconfig/laptop-mode ] ; then 347 # Others 348 . /etc/sysconfig/laptop-mode 349 fi 350 351 # Don't raise an error if the config file is incomplete 352 # set defaults instead: 353 354 # Maximum time, in seconds, of hard drive spindown time that you are 355 # comfortable with. Worst case, it's possible that you could lose this 356 # amount of work if your battery fails you while in laptop mode. 357 MAX_AGE=${MAX_AGE:-'600'} 358 359 # Read-ahead, in kilobytes 360 READAHEAD=${READAHEAD:-'4096'} 361 362 # Shall we remount journaled fs. with appropriate commit interval? (1=yes) 363 DO_REMOUNTS=${DO_REMOUNTS:-'1'} 364 365 # And shall we add the "noatime" option to that as well? (1=yes) 366 DO_REMOUNT_NOATIME=${DO_REMOUNT_NOATIME:-'1'} 367 368 # Shall we adjust the idle timeout on a hard drive? 369 DO_HD=${DO_HD:-'1'} 370 371 # Adjust idle timeout on which hard drive? 372 HD="${HD:-'/dev/hda'}" 373 374 # spindown time for HD (hdparm -S values) 375 AC_HD=${AC_HD:-'244'} 376 BATT_HD=${BATT_HD:-'4'} 377 378 # Dirty synchronous ratio. At this percentage of dirty pages the process which 379 # calls write() does its own writeback 380 DIRTY_RATIO=${DIRTY_RATIO:-'40'} 381 382 # cpu frequency scaling 383 # See Documentation/admin-guide/pm/cpufreq.rst for more info 384 DO_CPU=${CPU_MANAGE:-'0'} 385 CPU_MAXFREQ=${CPU_MAXFREQ:-'slowest'} 386 387 # 388 # Allowed dirty background ratio, in percent. Once DIRTY_RATIO has been 389 # exceeded, the kernel will wake flusher threads which will then reduce the 390 # amount of dirty memory to dirty_background_ratio. Set this nice and low, 391 # so once some writeout has commenced, we do a lot of it. 392 # 393 DIRTY_BACKGROUND_RATIO=${DIRTY_BACKGROUND_RATIO:-'5'} 394 395 # kernel default dirty buffer age 396 DEF_AGE=${DEF_AGE:-'30'} 397 DEF_UPDATE=${DEF_UPDATE:-'5'} 398 DEF_DIRTY_BACKGROUND_RATIO=${DEF_DIRTY_BACKGROUND_RATIO:-'10'} 399 DEF_DIRTY_RATIO=${DEF_DIRTY_RATIO:-'40'} 400 DEF_XFS_AGE_BUFFER=${DEF_XFS_AGE_BUFFER:-'15'} 401 DEF_XFS_SYNC_INTERVAL=${DEF_XFS_SYNC_INTERVAL:-'30'} 402 DEF_XFS_BUFD_INTERVAL=${DEF_XFS_BUFD_INTERVAL:-'1'} 403 404 # This must be adjusted manually to the value of HZ in the running kernel 405 # on 2.4, until the XFS people change their 2.4 external interfaces to work in 406 # centisecs. This can be automated, but it's a work in progress that still needs 407 # some fixes. On 2.6 kernels, XFS uses USER_HZ instead of HZ for external 408 # interfaces, and that is currently always set to 100. So you don't need to 409 # change this on 2.6. 410 XFS_HZ=${XFS_HZ:-'100'} 411 412 ############################################################################# 413 414 KLEVEL="$(uname -r | 415 { 416 IFS='.' read a b c 417 echo $a.$b 418 } 419 )" 420 case "$KLEVEL" in 421 "2.4"|"2.6") 422 ;; 423 *) 424 echo "Unhandled kernel version: $KLEVEL ('uname -r' = '$(uname -r)')" >&2 425 exit 1 426 ;; 427 esac 428 429 if [ ! -e /proc/sys/vm/laptop_mode ] ; then 430 echo "Kernel is not patched with laptop_mode patch." >&2 431 exit 1 432 fi 433 434 if [ ! -w /proc/sys/vm/laptop_mode ] ; then 435 echo "You do not have enough privileges to enable laptop_mode." >&2 436 exit 1 437 fi 438 439 # Remove an option (the first parameter) of the form option=<number> from 440 # a mount options string (the rest of the parameters). 441 parse_mount_opts () { 442 OPT="$1" 443 shift 444 echo ",$*," | sed \ 445 -e 's/,'"$OPT"'=[0-9]*,/,/g' \ 446 -e 's/,,*/,/g' \ 447 -e 's/^,//' \ 448 -e 's/,$//' 449 } 450 451 # Remove an option (the first parameter) without any arguments from 452 # a mount option string (the rest of the parameters). 453 parse_nonumber_mount_opts () { 454 OPT="$1" 455 shift 456 echo ",$*," | sed \ 457 -e 's/,'"$OPT"',/,/g' \ 458 -e 's/,,*/,/g' \ 459 -e 's/^,//' \ 460 -e 's/,$//' 461 } 462 463 # Find out the state of a yes/no option (e.g. "atime"/"noatime") in 464 # fstab for a given filesystem, and use this state to replace the 465 # value of the option in another mount options string. The device 466 # is the first argument, the option name the second, and the default 467 # value the third. The remainder is the mount options string. 468 # 469 # Example: 470 # parse_yesno_opts_wfstab /dev/hda1 atime atime defaults,noatime 471 # 472 # If fstab contains, say, "rw" for this filesystem, then the result 473 # will be "defaults,atime". 474 parse_yesno_opts_wfstab () { 475 L_DEV="$1" 476 OPT="$2" 477 DEF_OPT="$3" 478 shift 3 479 L_OPTS="$*" 480 PARSEDOPTS1="$(parse_nonumber_mount_opts $OPT $L_OPTS)" 481 PARSEDOPTS1="$(parse_nonumber_mount_opts no$OPT $PARSEDOPTS1)" 482 # Watch for a default atime in fstab 483 FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)" 484 if echo "$FSTAB_OPTS" | grep "$OPT" > /dev/null ; then 485 # option specified in fstab: extract the value and use it 486 if echo "$FSTAB_OPTS" | grep "no$OPT" > /dev/null ; then 487 echo "$PARSEDOPTS1,no$OPT" 488 else 489 # no$OPT not found -- so we must have $OPT. 490 echo "$PARSEDOPTS1,$OPT" 491 fi 492 else 493 # option not specified in fstab -- choose the default. 494 echo "$PARSEDOPTS1,$DEF_OPT" 495 fi 496 } 497 498 # Find out the state of a numbered option (e.g. "commit=NNN") in 499 # fstab for a given filesystem, and use this state to replace the 500 # value of the option in another mount options string. The device 501 # is the first argument, and the option name the second. The 502 # remainder is the mount options string in which the replacement 503 # must be done. 504 # 505 # Example: 506 # parse_mount_opts_wfstab /dev/hda1 commit defaults,commit=7 507 # 508 # If fstab contains, say, "commit=3,rw" for this filesystem, then the 509 # result will be "rw,commit=3". 510 parse_mount_opts_wfstab () { 511 L_DEV="$1" 512 OPT="$2" 513 shift 2 514 L_OPTS="$*" 515 PARSEDOPTS1="$(parse_mount_opts $OPT $L_OPTS)" 516 # Watch for a default commit in fstab 517 FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)" 518 if echo "$FSTAB_OPTS" | grep "$OPT=" > /dev/null ; then 519 # option specified in fstab: extract the value, and use it 520 echo -n "$PARSEDOPTS1,$OPT=" 521 echo ",$FSTAB_OPTS," | sed \ 522 -e 's/.*,'"$OPT"'=//' \ 523 -e 's/,.*//' 524 else 525 # option not specified in fstab: set it to 0 526 echo "$PARSEDOPTS1,$OPT=0" 527 fi 528 } 529 530 deduce_fstype () { 531 MP="$1" 532 # My root filesystem unfortunately has 533 # type "unknown" in /etc/mtab. If we encounter 534 # "unknown", we try to get the type from fstab. 535 cat /etc/fstab | 536 grep -v '^#' | 537 while read FSTAB_DEV FSTAB_MP FSTAB_FST FSTAB_OPTS FSTAB_DUMP FSTAB_DUMP ; do 538 if [ "$FSTAB_MP" = "$MP" ]; then 539 echo $FSTAB_FST 540 exit 0 541 fi 542 done 543 } 544 545 if [ $DO_REMOUNT_NOATIME -eq 1 ] ; then 546 NOATIME_OPT=",noatime" 547 fi 548 549 case "$1" in 550 start) 551 AGE=$((100*$MAX_AGE)) 552 XFS_AGE=$(($XFS_HZ*$MAX_AGE)) 553 echo -n "Starting laptop_mode" 554 555 if [ -d /proc/sys/vm/pagebuf ] ; then 556 # (For 2.4 and early 2.6.) 557 # This only needs to be set, not reset -- it is only used when 558 # laptop mode is enabled. 559 echo $XFS_AGE > /proc/sys/vm/pagebuf/lm_flush_age 560 echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval 561 elif [ -f /proc/sys/fs/xfs/lm_age_buffer ] ; then 562 # (A couple of early 2.6 laptop mode patches had these.) 563 # The same goes for these. 564 echo $XFS_AGE > /proc/sys/fs/xfs/lm_age_buffer 565 echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval 566 elif [ -f /proc/sys/fs/xfs/age_buffer ] ; then 567 # (2.6.6) 568 # But not for these -- they are also used in normal 569 # operation. 570 echo $XFS_AGE > /proc/sys/fs/xfs/age_buffer 571 echo $XFS_AGE > /proc/sys/fs/xfs/sync_interval 572 elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then 573 # (2.6.7 upwards) 574 # And not for these either. These are in centisecs, 575 # not USER_HZ, so we have to use $AGE, not $XFS_AGE. 576 echo $AGE > /proc/sys/fs/xfs/age_buffer_centisecs 577 echo $AGE > /proc/sys/fs/xfs/xfssyncd_centisecs 578 echo 3000 > /proc/sys/fs/xfs/xfsbufd_centisecs 579 fi 580 581 case "$KLEVEL" in 582 "2.4") 583 echo 1 > /proc/sys/vm/laptop_mode 584 echo "30 500 0 0 $AGE $AGE 60 20 0" > /proc/sys/vm/bdflush 585 ;; 586 "2.6") 587 echo 5 > /proc/sys/vm/laptop_mode 588 echo "$AGE" > /proc/sys/vm/dirty_writeback_centisecs 589 echo "$AGE" > /proc/sys/vm/dirty_expire_centisecs 590 echo "$DIRTY_RATIO" > /proc/sys/vm/dirty_ratio 591 echo "$DIRTY_BACKGROUND_RATIO" > /proc/sys/vm/dirty_background_ratio 592 ;; 593 esac 594 if [ $DO_REMOUNTS -eq 1 ]; then 595 cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do 596 PARSEDOPTS="$(parse_mount_opts "$OPTS")" 597 if [ "$FST" = 'unknown' ]; then 598 FST=$(deduce_fstype $MP) 599 fi 600 case "$FST" in 601 "ext3"|"reiserfs") 602 PARSEDOPTS="$(parse_mount_opts commit "$OPTS")" 603 mount $DEV -t $FST $MP -o remount,$PARSEDOPTS,commit=$MAX_AGE$NOATIME_OPT 604 ;; 605 "xfs") 606 mount $DEV -t $FST $MP -o remount,$OPTS$NOATIME_OPT 607 ;; 608 esac 609 if [ -b $DEV ] ; then 610 blockdev --setra $(($READAHEAD * 2)) $DEV 611 fi 612 done 613 fi 614 if [ $DO_HD -eq 1 ] ; then 615 for THISHD in $HD ; do 616 /sbin/hdparm -S $BATT_HD $THISHD > /dev/null 2>&1 617 /sbin/hdparm -B 1 $THISHD > /dev/null 2>&1 618 done 619 fi 620 if [ $DO_CPU -eq 1 -a -e /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq ]; then 621 if [ $CPU_MAXFREQ = 'slowest' ]; then 622 CPU_MAXFREQ=`cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq` 623 fi 624 echo $CPU_MAXFREQ > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq 625 fi 626 echo "." 627 ;; 628 stop) 629 U_AGE=$((100*$DEF_UPDATE)) 630 B_AGE=$((100*$DEF_AGE)) 631 echo -n "Stopping laptop_mode" 632 echo 0 > /proc/sys/vm/laptop_mode 633 if [ -f /proc/sys/fs/xfs/age_buffer -a ! -f /proc/sys/fs/xfs/lm_age_buffer ] ; then 634 # These need to be restored, if there are no lm_*. 635 echo $(($XFS_HZ*$DEF_XFS_AGE_BUFFER)) > /proc/sys/fs/xfs/age_buffer 636 echo $(($XFS_HZ*$DEF_XFS_SYNC_INTERVAL)) > /proc/sys/fs/xfs/sync_interval 637 elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then 638 # These need to be restored as well. 639 echo $((100*$DEF_XFS_AGE_BUFFER)) > /proc/sys/fs/xfs/age_buffer_centisecs 640 echo $((100*$DEF_XFS_SYNC_INTERVAL)) > /proc/sys/fs/xfs/xfssyncd_centisecs 641 echo $((100*$DEF_XFS_BUFD_INTERVAL)) > /proc/sys/fs/xfs/xfsbufd_centisecs 642 fi 643 case "$KLEVEL" in 644 "2.4") 645 echo "30 500 0 0 $U_AGE $B_AGE 60 20 0" > /proc/sys/vm/bdflush 646 ;; 647 "2.6") 648 echo "$U_AGE" > /proc/sys/vm/dirty_writeback_centisecs 649 echo "$B_AGE" > /proc/sys/vm/dirty_expire_centisecs 650 echo "$DEF_DIRTY_RATIO" > /proc/sys/vm/dirty_ratio 651 echo "$DEF_DIRTY_BACKGROUND_RATIO" > /proc/sys/vm/dirty_background_ratio 652 ;; 653 esac 654 if [ $DO_REMOUNTS -eq 1 ] ; then 655 cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do 656 # Reset commit and atime options to defaults. 657 if [ "$FST" = 'unknown' ]; then 658 FST=$(deduce_fstype $MP) 659 fi 660 case "$FST" in 661 "ext3"|"reiserfs") 662 PARSEDOPTS="$(parse_mount_opts_wfstab $DEV commit $OPTS)" 663 PARSEDOPTS="$(parse_yesno_opts_wfstab $DEV atime atime $PARSEDOPTS)" 664 mount $DEV -t $FST $MP -o remount,$PARSEDOPTS 665 ;; 666 "xfs") 667 PARSEDOPTS="$(parse_yesno_opts_wfstab $DEV atime atime $OPTS)" 668 mount $DEV -t $FST $MP -o remount,$PARSEDOPTS 669 ;; 670 esac 671 if [ -b $DEV ] ; then 672 blockdev --setra 256 $DEV 673 fi 674 done 675 fi 676 if [ $DO_HD -eq 1 ] ; then 677 for THISHD in $HD ; do 678 /sbin/hdparm -S $AC_HD $THISHD > /dev/null 2>&1 679 /sbin/hdparm -B 255 $THISHD > /dev/null 2>&1 680 done 681 fi 682 if [ $DO_CPU -eq 1 -a -e /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq ]; then 683 echo `cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq` > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq 684 fi 685 echo "." 686 ;; 687 *) 688 echo "Usage: $0 {start|stop}" 2>&1 689 exit 1 690 ;; 691 692 esac 693 694 exit 0 695 696 697ACPI integration 698---------------- 699 700Dax Kelson submitted this so that the ACPI acpid daemon will 701kick off the laptop_mode script and run hdparm. The part that 702automatically disables laptop mode when the battery is low was 703written by Jan Topinski. 704 705/etc/acpi/events/ac_adapter:: 706 707 event=ac_adapter 708 action=/etc/acpi/actions/ac.sh %e 709 710/etc/acpi/events/battery:: 711 712 event=battery.* 713 action=/etc/acpi/actions/battery.sh %e 714 715/etc/acpi/actions/ac.sh:: 716 717 #!/bin/bash 718 719 # ac on/offline event handler 720 721 status=`awk '/^state: / { print $2 }' /proc/acpi/ac_adapter/$2/state` 722 723 case $status in 724 "on-line") 725 /sbin/laptop_mode stop 726 exit 0 727 ;; 728 "off-line") 729 /sbin/laptop_mode start 730 exit 0 731 ;; 732 esac 733 734 735/etc/acpi/actions/battery.sh:: 736 737 #! /bin/bash 738 739 # Automatically disable laptop mode when the battery almost runs out. 740 741 BATT_INFO=/proc/acpi/battery/$2/state 742 743 if [[ -f /proc/sys/vm/laptop_mode ]] 744 then 745 LM=`cat /proc/sys/vm/laptop_mode` 746 if [[ $LM -gt 0 ]] 747 then 748 if [[ -f $BATT_INFO ]] 749 then 750 # Source the config file only now that we know we need 751 if [ -f /etc/default/laptop-mode ] ; then 752 # Debian 753 . /etc/default/laptop-mode 754 elif [ -f /etc/sysconfig/laptop-mode ] ; then 755 # Others 756 . /etc/sysconfig/laptop-mode 757 fi 758 MINIMUM_BATTERY_MINUTES=${MINIMUM_BATTERY_MINUTES:-'10'} 759 760 ACTION="`cat $BATT_INFO | grep charging | cut -c 26-`" 761 if [[ ACTION -eq "discharging" ]] 762 then 763 PRESENT_RATE=`cat $BATT_INFO | grep "present rate:" | sed "s/.* \([0-9][0-9]* \).*/\1/" ` 764 REMAINING=`cat $BATT_INFO | grep "remaining capacity:" | sed "s/.* \([0-9][0-9]* \).*/\1/" ` 765 fi 766 if (($REMAINING * 60 / $PRESENT_RATE < $MINIMUM_BATTERY_MINUTES)) 767 then 768 /sbin/laptop_mode stop 769 fi 770 else 771 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." 772 fi 773 fi 774 fi 775 776 777Monitoring tool 778--------------- 779 780Bartek Kania submitted this, it can be used to measure how much time your disk 781spends spun up/down. See tools/laptop/dslm/dslm.c 782