I configured power saving in two files.
My /etc/rc.local looks like the following:
#!/bin/sh -e # # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing. # runtime power management for i in `find /sys/devices/*/power/control`; do echo auto > $i; done; for i in `find /sys/bus/pci/devices/*/power/control`; do echo auto > $i; done; # usb autosuspend for i in `find /sys/bus/usb/devices/*/power/level`; do echo auto > $i; done; for i in `find /sys/bus/usb/devices/*/power/autosuspend`; do echo 2 > $i; done; exit 0
This takes care of several settings PowerTop refers to. I want these applied in all cases. Most of these are set by default, but I include these here to make certain.
I created a new file /etc/pm/power.d/powertop with the following:
# Power saving tunables # # The true case will trigger when on battery, false when on AC power case $1 in true) # nmi watchdog off echo 0 > /proc/sys/kernel/nmi_watchdog # vm writeback echo 1500 > /proc/sys/vm/dirty_writeback_centisecs # dim screen brightness on battery echo 0 > /sys/bus/pci/devices/0000:00:02.0/backlight/acpi_video0/brightness ;; false) #nmi watchdog on echo 1 > /proc/sys/kernel/nmi_watchdog # vm writeback echo 500 > /proc/sys/vm/dirty_writeback_centisecs # brighten screen brightness on AC echo 10 > /sys/bus/pci/devices/0000:00:02.0/backlight/acpi_video0/brightness ;; esac exit 0
Do a ‘chmod 755’ on the file. This will tweak some settings when on battery. It reverts to the default when on AC power.