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. 103 104 105Configuration 106------------- 107 108The laptop mode configuration file is located in /etc/default/laptop-mode on 109Debian-based systems, or in /etc/sysconfig/laptop-mode on other systems. It 110contains the following options: 111 112MAX_AGE: 113 114Maximum time, in seconds, of hard drive spindown time that you are 115comfortable with. Worst case, it's possible that you could lose this 116amount of work if your battery fails while you're in laptop mode. 117 118MINIMUM_BATTERY_MINUTES: 119 120Automatically disable laptop mode if the remaining number of minutes of 121battery power is less than this value. Default is 10 minutes. 122 123AC_HD/BATT_HD: 124 125The idle timeout that should be set on your hard drive when laptop mode 126is active (BATT_HD) and when it is not active (AC_HD). The defaults are 12720 seconds (value 4) for BATT_HD and 2 hours (value 244) for AC_HD. The 128possible values are those listed in the manual page for "hdparm" for the 129"-S" option. 130 131HD: 132 133The devices for which the spindown timeout should be adjusted by laptop mode. 134Default is /dev/hda. If you specify multiple devices, separate them by a space. 135 136READAHEAD: 137 138Disk readahead, in 512-byte sectors, while laptop mode is active. A large 139readahead can prevent disk accesses for things like executable pages (which are 140loaded on demand while the application executes) and sequentially accessed data 141(MP3s). 142 143DO_REMOUNTS: 144 145The control script automatically remounts any mounted journaled filesystems 146with appropriate commit interval options. When this option is set to 0, this 147feature is disabled. 148 149DO_REMOUNT_NOATIME: 150 151When remounting, should the filesystems be remounted with the noatime option? 152Normally, this is set to "1" (enabled), but there may be programs that require 153access time recording. 154 155DIRTY_RATIO: 156 157The percentage of memory that is allowed to contain "dirty" or unsaved data 158before a writeback is forced, while laptop mode is active. Corresponds to 159the /proc/sys/vm/dirty_ratio sysctl. 160 161DIRTY_BACKGROUND_RATIO: 162 163The percentage of memory that is allowed to contain "dirty" or unsaved data 164after a forced writeback is done due to an exceeding of DIRTY_RATIO. Set 165this nice and low. This corresponds to the /proc/sys/vm/dirty_background_ratio 166sysctl. 167 168Note that the behaviour of dirty_background_ratio is quite different 169when laptop mode is active and when it isn't. When laptop mode is inactive, 170dirty_background_ratio is the threshold percentage at which background writeouts 171start taking place. When laptop mode is active, however, background writeouts 172are disabled, and the dirty_background_ratio only determines how much writeback 173is done when dirty_ratio is reached. 174 175DO_CPU: 176 177Enable CPU frequency scaling when in laptop mode. (Requires CPUFreq to be setup. 178See Documentation/admin-guide/pm/cpufreq.rst for more info. Disabled by default.) 179 180CPU_MAXFREQ: 181 182When on battery, what is the maximum CPU speed that the system should use? Legal 183values are "slowest" for the slowest speed that your CPU is able to operate at, 184or a value listed in /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies. 185 186 187Tips & 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 218Configuration file for control and ACPI battery scripts 219------------------------------------------------------- 220 221This allows the tunables to be changed for the scripts via an external 222configuration file 223 224It 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 227Config 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 305Control script 306-------------- 307 308Please note that this control script works for the Linux 2.4 and 2.6 series (thanks 309to Kiko Piris). 310 311Control 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 686ACPI integration 687---------------- 688 689Dax Kelson submitted this so that the ACPI acpid daemon will 690kick off the laptop_mode script and run hdparm. The part that 691automatically disables laptop mode when the battery is low was 692written 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 766Monitoring tool 767--------------- 768 769Bartek Kania submitted this, it can be used to measure how much time your disk 770spends spun up/down. See tools/laptop/dslm/dslm.c 771