C[omp]ute

From: "andrew cooke" <andrew@...>

Date: Sat, 29 Nov 2008 17:46:47 -0300 (CLST)

I just bought a new battery and decided to see if I could extend its life
by careful configuration of my system.  Typically I use my laptop plugged
into the mains at home, and so don't need a battery except if I'm carrying
it from one room to another.  The only time I really rely on the battery
is when I am flying, and then typically I want to get some work done, but
have no need for sound or an internet connection.

So what follows is a bit extreme, perhaps, because I only intend to use it
when, for example, on an aeroplane.

First, I disabled 3d acceleration on the graphics (this is a checkbox
inside SAX - if you go to the Yast GUI thing for the display you'll see
it).  That has made the fonts uglier (and smaller) for some reason.

Second, I run the following script as root immediately after booting (by
hand, once I have logged in).

Together, that lowers the number of interrupts to the low 10s per second
(this is the number that the powertop tool focuses on - it means that the
CPU can stay in its idle state for longer).

Andrew

PS Here's the script - it's quite possible that some things are
unnecessary; I just kept piling stuff on until the numbers went down...

#!/bin/bash

/etc/init.d/mysql stop
/etc/init.d/powersaved stop
/etc/init.d/ntp stop
/etc/init.d/sshd stop
/etc/init.d/network stop

ifconfig wlan0 down
ifconfig eth0 down

mount -o remount,noatime /

echo min_power > /sys/class/scsi_host/host0/link_power_management_policy
echo 1500 > /proc/sys/vm/dirty_writeback_centisecs
ethtool -s eth0 wol d

killall NetworkManager
killall gaim
killall kopete
killall synergyc
killall skype
killall kaffeine
killall gkrellm
killall artsd
killall kpowersave
killall kpowersaved
killall knetworkmanager
killall kmix
killall klipper
killall acpid

for module in thinkpad_acpi pcmia yenta_socket snd_pcm_oss snd_seq
snd_seq_device snd_hda_intel snd_pcm snd_timer snd_hwdep snd_mixer_oss
snd_page_alloc snd processoracpi_cpufreq ehci_hcd uhci_hcd usbcore e1000e;
do
  echo "$module"
  if `lsmod | grep "$module"`; then
    rmmod "$module"
  fi
done