diff options
Diffstat (limited to 'pm/power.d/laptop-mode')
| -rw-r--r-- | pm/power.d/laptop-mode | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/pm/power.d/laptop-mode b/pm/power.d/laptop-mode index 844ac85..5f873db 100644 --- a/pm/power.d/laptop-mode +++ b/pm/power.d/laptop-mode @@ -13,22 +13,36 @@ LAPTOP_DIRTY_WRITEBACK=${LAPTOP_DIRTY_WRITEBACK:-60000} help() { cat <<EOF -Laptop mode VM tuning parameters: +-------- +$0: Laptop mode tuning parameters. +This hook controls how agressive the system is at trying to avoid +writing to disk. The longer the disk is idle, the more power you can save. +This hook is only active on battery power, and it restores these values +to kernel defaults when on AC power. + +It has 4 tuneable parameters: LAPTOP_MODE = value for laptop_mode on battery. -Defaults to 1, which enables laptop mode. +Defaults to 5, which enables laptop mode and forces the system to wait +5 seconds whenever something asks to write to disk to flush out as much +data as we can. LAPTOP_DIRTY_RATIO = the ratio of dirty memory to all memory that -processes start doing their own writeout. Defaults to 60. +processes start doing their own writeout. +Defaults to 60, which means that the kernel will not start forcing process +to write out file information that has been changed but not saved until 60% +of usable system memory is filled with dirty information. LAPTOP_DIRTY_BG_RATIO = The ratio of dirty memory to all memory that -pdflush will wake up and start writing to disk. Defaults to 40. +pdflush will wake up and start writing to disk. +Defaults to 40, which means that the kernel will wake up a helper process +to try and write out dirty memory once 40% of usable system memory is dirty. LAPTOP_DIRTY_WRITEBACK = The number of centiseconds between periodic -wakeups of the pdflush daemons. Defaults to 60000 (10 minutes). +wakeups of the pdflush daemons. +Defaults to 60000 (10 minutes), which menas that the kernel will flush dirty +memory every 10 minutes if dirty memory never hits 40% of system memory. -These only take place on battery. This hook will revert to the kernel -default values on AC power. EOF } |