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swift 11/09/23 18:41:52 |
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|
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Modified: power-management-guide.xml |
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Log: |
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Fix bugs #379523 and #381059, rewrite power management guide reflecting recent developments in userspace support |
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|
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Revision Changes Path |
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1.49 xml/htdocs/doc/en/power-management-guide.xml |
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|
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file : http://sources.gentoo.org/viewvc.cgi/gentoo/xml/htdocs/doc/en/power-management-guide.xml?rev=1.49&view=markup |
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plain: http://sources.gentoo.org/viewvc.cgi/gentoo/xml/htdocs/doc/en/power-management-guide.xml?rev=1.49&content-type=text/plain |
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diff : http://sources.gentoo.org/viewvc.cgi/gentoo/xml/htdocs/doc/en/power-management-guide.xml?r1=1.48&r2=1.49 |
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|
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Index: power-management-guide.xml |
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=================================================================== |
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RCS file: /var/cvsroot/gentoo/xml/htdocs/doc/en/power-management-guide.xml,v |
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retrieving revision 1.48 |
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retrieving revision 1.49 |
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diff -u -r1.48 -r1.49 |
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--- power-management-guide.xml 17 Aug 2011 07:19:29 -0000 1.48 |
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+++ power-management-guide.xml 23 Sep 2011 18:41:52 -0000 1.49 |
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@@ -1,109 +1,74 @@ |
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<?xml version='1.0' encoding="UTF-8"?> |
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<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> |
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-<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/power-management-guide.xml,v 1.48 2011/08/17 07:19:29 swift Exp $ --> |
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+<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/power-management-guide.xml,v 1.49 2011/09/23 18:41:52 swift Exp $ --> |
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|
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<guide> |
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<title>Power Management Guide</title> |
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|
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<author title="Author"> |
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- <mail link="earthwings@g.o">Dennis Nienhüser</mail> |
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-</author> |
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-<author title="Editor"> |
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- <mail link="chriswhite@g.o">Chris White</mail> |
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-</author> |
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-<author title="Editor"> |
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- <mail link="nightmorph"/> |
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+ <mail link="swift"/> |
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</author> |
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|
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<abstract> |
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-Power Management is the key to extend battery run time on mobile systems like |
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-laptops. This guide assists you setting it up on your laptop. |
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+In recent years, power management has become one of the differentiating |
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+features in the quest for finding the perfect laptop. Yet, the operating system |
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+must support the various power saving functionalities too. In this guide, we |
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+cover how to setup your Gentoo installation so it manages power-hungry resources |
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+in a flexible yet automated manner. |
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</abstract> |
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|
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<!-- The content of this document is licensed under the CC-BY-SA license --> |
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<!-- See http://creativecommons.org/licenses/by-sa/2.5 --> |
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<license/> |
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|
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-<version>4</version> |
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-<date>2011-08-17</date> |
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+<version>5</version> |
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+<date>2011-09-22</date> |
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|
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<chapter> |
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<title>Introduction</title> |
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<section> |
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+<title>About this document...</title> |
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<body> |
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|
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-<!-- |
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- Remove this note after 6 months - ETA 01/02/2012 |
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- By then, we can assume that OpenRC migrations are not that frequent |
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- anymore and this note can be dropped. |
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- ~ Sven Vermeulen |
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---> |
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-<impo> |
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-Since the introduction of OpenRC, the <c>pmg_switch_runlevel.sh</c> script |
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-needs to be updated. If you have issues after the OpenRC upgrade, please update |
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-this script according to this guide. |
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-</impo> |
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+<p> |
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+This document describes the setup of power management features on your laptop. |
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+Although some of the information in this guide can be applied to power |
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+management for servers, it is not the intention of this document to go that |
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+route. Please be careful when applying this on a non-laptop system. |
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+</p> |
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|
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<p> |
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-Capacity and lifetime of laptop batteries have improved much in the last years. |
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-Nevertheless modern processors consume much more energy than older ones and |
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-each laptop generation introduces more devices hungry for energy. That's why |
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-Power Management is more important than ever. Increasing battery run time |
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-doesn't necessarily mean buying another battery. Much can be achieved applying |
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-intelligent Power Management policies. |
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+Within this document, we will focus primarily on the laptop mode tools since it |
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+offers a complete set of functionalities. However, we will also refer to other |
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+tools that might offer a more detailed approach on individual settings. In such |
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+cases, you will need to disable the feature from the laptop mode tools so that |
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+both tools do not fight over the same resource control. |
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</p> |
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|
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</body> |
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</section> |
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<section> |
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-<title>A Quick Overview</title> |
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+<title>About laptop_mode</title> |
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<body> |
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|
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<p> |
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-Please notice that this guide describes Power Management for <e>laptops</e>. |
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-While some sections might also suite for <e>servers</e>, others do not and may |
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-even cause harm. Please do not apply anything from this guide to a server |
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-unless you really know what you are doing. |
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-</p> |
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- |
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-<p> |
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-As this guide has become rather long, here's a short overview helping you to |
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-find your way through it. |
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-</p> |
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- |
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-<p> |
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-The <uri link="#doc_chap2">Prerequisites</uri> chapter talks about some |
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-requirements that should be met before any of the following device individual |
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-sections will work. This includes BIOS settings, kernel configuration and some |
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-simplifications in user land. The following three chapters focus on devices |
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-that typically consume most energy - processor, display and hard drive. Each |
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-can be configured separately. <uri link="#doc_chap3">CPU Power Management</uri> |
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-shows how to adjust the processor's frequency to save a maximum of energy |
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-without losing too much performance. A few different tricks prevent your hard |
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-drive from working unnecessarily often in <uri link="#doc_chap5">Disk Power |
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-Management</uri> (decreasing noise level as a nice side effect). Some notes on |
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-graphics cards, Wireless LAN and USB finish the device section in <uri |
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-link="#doc_chap6">Power Management For Other Devices</uri> while another |
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-chapter is dedicated to the (rather experimental) <uri link="#doc_chap7">sleep |
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-states</uri>. Last not least <uri link="#doc_chap8">Troubleshooting</uri> lists |
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-common pitfalls. |
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+The <c>laptop_mode</c> setting is an in-kernel configuration setting that |
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+optimizes I/O, allowing disks to spin down properly (and not be woken up |
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+immediately afterwards for queued operations). |
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</p> |
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|
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</body> |
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</section> |
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<section> |
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-<title>Power Budget For Each Component</title> |
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+<title>About laptop-mode-tools</title> |
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<body> |
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|
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-<figure link="/images/energy-budget.png" short="Which component consumes how |
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-much energy?" caption="Power budget for each component"/> |
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- |
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<p> |
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-Nearly every component can operate in different states - off, sleep, idle, |
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-active to name a few - consuming a different amount of energy. Major parts are |
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-consumed by the LCD display, CPU, chipset and hard drives. Often one is able to |
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-activate OS-independent Power Management in the BIOS, but an intelligent setup |
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-in the operating system adapting to different situations can achieve much more. |
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+The <e>Laptop Mode Tools</e> is a software package |
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+(<c>app-laptop/laptop-mode-tools</c>) which allows the user to optimize power |
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+saving functions. It allows managing the <c>laptop_mode</c> setting in the Linux |
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+kernel, but has additional features allowing you to tweak other power-related |
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+settings on the system. |
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</p> |
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|
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</body> |
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@@ -111,881 +76,566 @@ |
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</chapter> |
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|
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<chapter> |
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-<title>Prerequisites</title> |
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+<title>Linux Kernel Configuration</title> |
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<section> |
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+<title>Minimum kernel setup</title> |
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<body> |
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|
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<p> |
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-Before discussing the details of making individual devices Power Management |
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-aware, make sure certain requirements are met. After controlling BIOS settings, |
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-some kernel options want to be enabled - these are in short ACPI, sleep states |
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-and CPU frequency scaling. As power saving most of the time comes along with |
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-performance loss or increased latency, it should only be enabled when running |
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-on batteries. That's where a new runlevel <e>battery</e> comes in handy. |
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+There are different kernel sources in Portage. We recommend using |
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+<c>gentoo-sources</c>, but if you want advanced hibernation support you might |
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+need <c>tuxonice-sources</c>. To enable proper power management features in the |
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+Linux kernel, enable at least the following settings: |
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</p> |
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|
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-</body> |
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-</section> |
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-<section> |
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-<title>The BIOS Part</title> |
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-<body> |
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+<pre caption="Minimum kernel setup for Power Management (Kernel 2.6)"> |
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+<![CDATA[ |
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+General setup ---> |
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+ [*] Configure standard kernel features (expert users) ---> |
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+ |
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+Power management and ACPI options ---> |
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+ [*] ACPI (Advanced Configuration and Power Interface) Support ---> |
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+ <*> AC Adapter |
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+ <*> Battery |
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+ -*- Button |
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+ -*- Video |
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+ <*> Fan |
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+ <*> Processor |
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+ <*> Thermal Zone |
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+ [*] Power Management Timer Support |
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+ |
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+ [*] CPU Frequency scaling ---> |
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+ [*] CPU Frequency scaling |
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+ <*> 'performance' governor |
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+ <*> 'powersave' governor |
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+ <*> 'userspace' governor |
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+ <*> 'ondemand' governor |
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+ <*> 'conservative' governor |
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+ <*> ACPI Processor P-States driver |
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+]]> |
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+</pre> |
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|
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<p> |
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-First have a look into your BIOS Power Management settings. The best way is to |
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-combine BIOS and operating system policies, but for the moment it's better to |
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-disable most of the BIOS part. This makes sure it doesn't interfere with your |
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-policies. Don't forget to re-check BIOS settings after you configured |
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-everything else. |
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+Don't forget to enable the CPU frequency scaling driver for your CPU, located |
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+right after the <e>ACPI Processor P-States driver</e> mentioned above. |
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</p> |
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|
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-</body> |
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-</section> |
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-<section> |
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-<title>Setting USE Flags</title> |
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-<body> |
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- |
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<p> |
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-Please check that the <c>acpi</c> USE flag is set in |
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-<path>/etc/make.conf</path>. Other USE flags that might be interesting for your |
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-system are <c>apm</c>, <c>lm_sensors</c>, <c>nforce2</c>, <c>nvidia</c>, |
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-<c>pmu</c>. See <path>/usr/portage/profiles/use*.desc</path> for details. If |
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-you forgot to set one of these flags, you can recompile affected packages using |
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-the <c>--newuse</c> flag in <c>emerge</c>, see <c>man emerge</c>. |
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+Build and install the new kernel (if necessary) and reboot. |
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</p> |
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|
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</body> |
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</section> |
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-<section> |
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-<title>Configuring The Kernel</title> |
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+<!-- |
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+<section id="kernelconfig"> |
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+<title>Additional kernel configuration entries</title> |
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<body> |
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|
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<p> |
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-ACPI (Advanced Configuration and Power Interface) support in the kernel is |
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-still work in progress. Using a recent kernel will make sure you'll get the |
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-most out of it. |
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+Further down this guide, additional kernel settings might be suggested. To |
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+lessen the effort to maintain the guide, and to make sure settings are correctly |
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+identified, we will use the kernel configuration short-hand notations. These |
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+notations are simple strings, like <c>CONFIG_USB_SUSPEND</c>. But how to read |
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+this? |
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</p> |
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|
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<p> |
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-There are different kernel sources in Portage. I'd recommend using |
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-<c>gentoo-sources</c> or <c>tuxonice-sources</c>. The latter contains patches |
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-for TuxOnIce, see the chapter about <uri link="#doc_chap7">sleep states</uri> |
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-for more details. When configuring the kernel, activate at least these options: |
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+Well, then you configure your kernel (through <c>make menuconfig</c>), you can |
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+search through the configuration settings for a particular entry. Press <c>/</c> |
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+while configuring the Linux kernel and type the setting |
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+(<c>CONFIG_USB_SUSPEND</c>). The software will tell you what the setting is, |
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+what it is for, when you can select it (i.e. on which settings it depends before |
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+you can see it) but most importantly, where you can find it. |
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</p> |
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|
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-<pre caption="Minimum kernel setup for Power Management (Kernel 2.6)"> |
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-Power management and ACPI options ---> |
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-[*] Power Management support |
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- [ ] Software Suspend |
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- |
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- ACPI( Advanced Configuration and Power Interface ) Support ---> |
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- [ ] Deprecated /proc/acpi/ files |
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- [*] AC Adapter |
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- [*] Battery |
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- <M> Button |
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- <M> Video |
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- [ ] Generic Hotkey |
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- <M> Fan |
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- <M> Processor |
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- <M> Thermal Zone |
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- < > ASUS/Medion Laptop Extras |
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- < > IBM ThinkPad Laptop Extras |
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- < > Toshiba Laptop Extras |
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- (0) Disable ACPI for systems before Jan 1st this year |
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- [ ] Debug Statements |
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- [*] Power Management Timer Support |
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- < > ACPI0004,PNP0A05 and PNP0A06 Container Driver (EXPERIMENTAL) |
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- |
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- CPU Frequency Scaling ---> |
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- [*] CPU Frequency scaling |
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- [ ] Enable CPUfreq debugging |
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- < > CPU frequency translation statistics |
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- [ ] CPU frequency translation statistics details |
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- Default CPUFreq governor (userspace) |
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- <*> 'performance' governor |
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- <*> 'powersave' governor |
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- <*> 'ondemand' cpufreq policy governor |
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- <*> 'conservative' cpufreq governor |
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- <*> CPU frequency table helpers |
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- <M> ACPI Processor P-States driver |
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- <*> <i>CPUFreq driver for your processor</i> |
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+<pre caption="Result of a search operation during menuconfig"> |
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+<![CDATA[Symbol: USB_SUSPEND [=n] |
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+Type : boolean |
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+Prompt: USB runtime power management (autosuspend) and wakeup |
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+ Defined at drivers/usb/core/Kconfig:93 |
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+ Depends on: USB_SUPPORT [=y] && USB [=y] && PM_RUNTIME [=n] |
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+ Location: |
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+ -> Device Drivers |
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+ -> USB support (USB_SUPPORT [=y]) |
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+ -> Support for Host-side USB (USB [=y]) ]]> |
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</pre> |
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|
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-<p> |
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-Decide yourself whether you want to enable Software Suspend, and Sleep States |
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-(see below). If you own an ASUS, Medion, IBM Thinkpad or Toshiba laptop, enable |
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-the appropriate section. |
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-</p> |
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+</body> |
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+</section> |
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+--> |
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+</chapter> |
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+ |
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+<chapter> |
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+<title>Using Laptop Mode Tools</title> |
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+<section> |
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+<title>Installation</title> |
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+<body> |
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|
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<p> |
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-The kernel has to know how to enable CPU frequency scaling on your processor. |
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-As each type of CPU has a different interface, you've got to choose the right |
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-driver for your processor. Be careful here - enabling <c>Intel Pentium 4 clock |
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-modulation</c> on a Pentium M system will lead to strange results for example. |
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-Consult the kernel documentation if you're unsure which one to take. |
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+It comes to no surprise that installation of the <e>Laptop Mode Tools</e> |
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+software is easily done through <c>emerge laptop-mode-tools</c>. However, this |
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+package takes on additional, optional settings through USE flag configuration. |
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+So let's first take a look at the supported USE flags and what they mean to the |
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+package. |
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</p> |
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|
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+<table> |
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+<tr> |
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+ <th>USE flag</th> |
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+ <th>Description</th> |
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+ <th>Suggested when...</th> |
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+</tr> |
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+<tr> |
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+ <ti>acpi</ti> |
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+ <ti> |
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+ Depend on <c>sys-power/acpid</c> so that changes in the system are |
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+ captured and power saving features are automatically enabled/disabled. |
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+ </ti> |
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+ <ti>your laptop is not too old (~ year 2003 and later)</ti> |
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+</tr> |
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+<tr> |
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+ <ti>apm</ti> |
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+ <ti> |
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+ Depend on <c>sys-apps/apmd</c> so that changes in the system are captured |
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+ and power saving features are automatically enabled/disabled. |
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+ </ti> |
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+ <ti>your laptop is very old</ti> |
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+</tr> |
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+<tr> |
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+ <ti>bluetooth</ti> |
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+ <ti> |
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+ Depend on <c>net-wireless/bluez</c>, enabling the <c>laptop-mode-tools</c> |
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+ to manage bluetooth settings (enabling/disabling the service based on |
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+ battery availability) |
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+ </ti> |
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+ <ti>your laptop (and kernel) supports bluetooth</ti> |
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+</tr> |
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+<tr> |
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+ <ti>scsi</ti> |
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+ <ti> |
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+ Depend on <c>sys-apps/sdparm</c>, enabling the <c>laptop-mode-tools</c> to |
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+ manage SCSI (<e>and not</e> SATA) disk parameters. |
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+ </ti> |
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+ <ti>your laptop uses SCSI disks</ti> |
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+</tr> |
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+</table> |
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+ |
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<p> |
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-Compile your kernel, make sure the right modules get loaded at startup and boot |
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-into your new ACPI-enabled kernel. Next run <c>emerge sys-power/acpid</c> to |
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-get the acpi daemon. This one informs you about events like switching from AC |
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-to battery or closing the lid. Make sure the modules are loaded if you didn't |
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-compile them into the kernel and start acpid by executing <c>/etc/init.d/acpid |
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-start</c>. Run <c>rc-update add acpid default</c> to load it on startup. You'll |
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-soon see how to use it. |
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+As you can see, there are two USE flags that seem to collide: <c>acpi</c> and |
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+<c>apm</c>. So what's the deal there? |
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</p> |
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|
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-<pre caption="Installing acpid"> |
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-# <i>emerge sys-power/acpid</i> |
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-# <i>/etc/init.d/acpid start</i> |
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-# <i>rc-update add acpid default</i> |
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-</pre> |
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+<ul> |
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+ <li> |
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+ The <c>apm</c> USE flag enables support for <e>Advanced Power |
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+ Management</e>, an older (before year 2000) standard for power management |
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+ features within a system. |
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+ </li> |
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+ <li> |
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+ The <c>acpi</c> USE flag enables support for <e>Advanced Configuration and |
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+ Power Interface</e>, the successor of APM. All modern laptops support ACPI. |
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+ </li> |
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+</ul> |
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|
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-</body> |
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-</section> |
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-<section> |
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-<title>Creating A "battery" Runlevel</title> |
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-<body> |
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+<p> |
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+Depending on your system, you will either need <c>acpi</c> or <c>apm</c> set. In |
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+the remainder of this guide, we assume that your laptop is recent enough to use |
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+ACPI. |
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+</p> |
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|
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<p> |
436 |
-The default policy will be to enable Power Management only when needed - |
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-running on batteries. To make the switch between AC and battery convenient, |
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-create a runlevel <c>battery</c> that holds all the scripts starting and |
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-stopping Power Management. |
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+So, with the USE flags set, let's install <c>laptop-mode-tools</c>. |
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</p> |
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|
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<note> |
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-You can safely skip this section if you don't like the idea of having another |
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-runlevel. However, skipping this step will make the rest a bit trickier to set |
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-up. The next sections assume a runlevel <c>battery</c> exists. |
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+If you have USE="acpi" set, the installation will pull in <c>acpid</c>. However, |
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+the current stable ACPI daemon (2.0.9) does not support the new ACPI interfaces |
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+within the Linux kernel (using the netlink interface). As such, we recommend |
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+unmasking <c>sys-power/acpid-2.0.12</c> (or higher). For more information about |
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+unmasking packages, please read |
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+<uri link="/doc/en/handbook/handbook-amd64.xml?part=3&chap=3">Mixing Software |
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+Branches</uri> in the Gentoo Handbook. |
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</note> |
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|
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-<pre caption="Creating a battery runlevel"> |
457 |
-# <i>cd /etc/runlevels</i> |
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-# <i>cp -a default battery</i> |
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+<pre caption="Installing laptop-mode-tools"> |
460 |
+# <i>emerge laptop-mode-tools</i> |
461 |
</pre> |
462 |
|
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-<p> |
464 |
-Finished. Your new runlevel <c>battery</c> contains everything like |
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-<c>default</c>, but there is no automatic switch between both yet. Time to |
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-change it. |
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-</p> |
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- |
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</body> |
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</section> |
471 |
<section> |
472 |
-<title>Reacting On ACPI Events</title> |
473 |
+<title>Configuration</title> |
474 |
<body> |
475 |
|
476 |
<p> |
477 |
-Typical ACPI events are closing the lid, changing the power source or pressing |
478 |
-the sleep button. An important event is changing the power source, which should |
479 |
-cause a runlevel switch. A small script will take care of it. |
480 |
-</p> |
481 |
- |
482 |
-<p> |
483 |
-First you need a script which changes the runlevel to <c>default</c> |
484 |
-respectively <c>battery</c> depending on the power source. The script uses the |
485 |
-<c>on_ac_power</c> command from <c>sys-power/pm-utils</c> - make sure the |
486 |
-package is installed on your system. |
487 |
+Having <c>laptop-mode-tools</c> installed on your system does not automatically |
488 |
+enable the power management features that you might need. To configure the |
489 |
+package, first take a look at <path>/etc/laptop-mode/laptop-mode.conf</path>. |
490 |
+This is the main configuration file for the package and is pretty well described |
491 |
+(through comments). |
492 |
</p> |
493 |
|
494 |
-<pre caption="Installing pm-utils"> |
495 |
-# <i>emerge pm-utils</i> |
496 |
-</pre> |
497 |
- |
498 |
-<p> |
499 |
-You are now able to determine the power source by executing <c>on_ac_power |
500 |
-&& echo AC available || echo Running on batteries</c> in a shell. The |
501 |
-script below is responsible for changing runlevels. Save it as |
502 |
-<path>/etc/acpi/actions/pmg_switch_runlevel.sh</path>. |
503 |
-</p> |
504 |
- |
505 |
-<pre caption="/etc/acpi/actions/pmg_switch_runlevel.sh"> |
506 |
-#!/bin/bash |
507 |
- |
508 |
-# BEGIN configuration |
509 |
-RUNLEVEL_AC="default" |
510 |
-RUNLEVEL_BATTERY="battery" |
511 |
- |
512 |
-if [ -x /usr/bin/logger ]; then |
513 |
- LOGGER="/usr/bin/logger -s -p daemon.info -t /etc/acpi/actions/pmg_switch_runlevel.sh" |
514 |
-else |
515 |
- LOGGER="/bin/echo" |
516 |
-fi |
517 |
- |
518 |
-ON_AC_POWER=/usr/bin/on_ac_power |
519 |
-# END configuration |
520 |
- |
521 |
- |
522 |
-if [ ! -d "/etc/runlevels/${RUNLEVEL_AC}" ] |
523 |
-then |
524 |
- ${LOGGER} "${0}: Runlevel ${RUNLEVEL_AC} does not exist. Aborting." |
525 |
- exit 1 |
526 |
-fi |
527 |
- |
528 |
-if [ ! -d "/etc/runlevels/${RUNLEVEL_BATTERY}" ] |
529 |
-then |
530 |
- ${LOGGER} "${0}: Runlevel ${RUNLEVEL_BATTERY} does not exist. Aborting." |
531 |
- exit 1 |
532 |
-fi |
533 |
- |
534 |
-if ${on_ac_power} |
535 |
-then |
536 |
- if [[ "$(rc-status --runlevel)" != "${RUNLEVEL_AC}" ]] |
537 |
- then |
538 |
- ${LOGGER} "Switching to ${RUNLEVEL_AC} runlevel" |
539 |
- /sbin/rc ${RUNLEVEL_AC} |
540 |
- fi |
541 |
-elif [[ "$(rc-status --runlevel)" != "${RUNLEVEL_BATTERY}" ]] |
542 |
-then |
543 |
- ${LOGGER} "Switching to ${RUNLEVEL_BATTERY} runlevel" |
544 |
- /sbin/rc ${RUNLEVEL_BATTERY} |
545 |
-fi |
546 |
-</pre> |
547 |
- |
548 |
<p> |
549 |
-Dont forget to run <c>chmod +x /etc/acpi/actions/pmg_switch_runlevel.sh</c> to |
550 |
-make the script executable. The last thing that needs to be done is calling the |
551 |
-script whenever the power source changes. That's done by catching ACPI events |
552 |
-with the help of <c>acpid</c>. First you need to know which events are |
553 |
-generated when the power source changes. The events are called |
554 |
-<c>ac_adapter</c> and <c>battery</c> on most laptops, but it might be different |
555 |
-on yours. |
556 |
+But it is not the only configuration file to work with. The Laptop Mode Tools |
557 |
+package supports plugins (or modules) which have their own configuration |
558 |
+file(s). These files are located in <path>/etc/laptop-mode/conf.d</path> and are |
559 |
+named after the module they represent (such as |
560 |
+<path>intel-sata-powermgmt.conf</path>). |
561 |
</p> |
562 |
|
563 |
-<pre caption="Determining ACPI events for changing the power source"> |
564 |
-# <i>tail -f /var/log/messages | grep "ACPI event"</i> |
565 |
-</pre> |
566 |
- |
567 |
<p> |
568 |
-Run the command above and pull the power cable. You should see something like |
569 |
-this: |
570 |
+Now, one of the important settings in each configuration file is if the Laptop |
571 |
+Mode Tools package should govern a particular setting or not. This is important |
572 |
+when you want to combine <c>laptop-mode-tools</c> with other services like |
573 |
+<c>cpufreqd</c>. In this example case, you will need to set |
574 |
+<c>CONTROL_CPU_FREQUENCY=0</c>: |
575 |
</p> |
576 |
|
577 |
-<pre caption="Sample output for power source changes"> |
578 |
-[Tue Sep 20 17:39:06 2005] ACPI event "ac_adapter AC 00000080 00000000" |
579 |
-[Tue Sep 20 17:39:06 2005] ACPI event "battery BAT0 00000080 00000001" |
580 |
+<pre caption="Editing /etc/laptop-mode/conf.d/cpufreq.conf"> |
581 |
+# <i>nano -w /etc/laptop-mode/conf.d/cpufreq.conf</i> |
582 |
+CONTROL_CPU_FREQUENCY=<i>0</i> |
583 |
</pre> |
584 |
|
585 |
<p> |
586 |
-The interesting part is the quoted string after <c>ACPI event</c>. It will |
587 |
-be matched by the event line in the files you are going to create below. Don't |
588 |
-worry if your system generates multiple events or always the same. As long as |
589 |
-any event is generated, runlevel changing will work. |
590 |
+The next few sections will help you configure <c>laptop-mode-tools</c> to suit |
591 |
+your needs. When you are finished, start the <c>laptop_mode</c> service and make |
592 |
+sure it is started when you boot up your system. |
593 |
</p> |
594 |
|
595 |
-<pre caption="/etc/acpi/events/pmg_ac_adapter"> |
596 |
-<comment># replace "ac_adapter" below with the event generated on your laptop</comment> |
597 |
-<comment># For example, ac_adapter.* will match ac_adapter AC 00000080 00000000</comment> |
598 |
-event=ac_adapter.* |
599 |
-action=/etc/acpi/actions/pmg_switch_runlevel.sh %e |
600 |
+<pre caption="Starting the laptop_mode service"> |
601 |
+# <i>/etc/init.d/laptop_mode start</i> |
602 |
+# <i>rc-update add laptop_mode default</i> |
603 |
</pre> |
604 |
|
605 |
-<pre caption="/etc/acpi/events/pmg_battery"> |
606 |
-<comment># replace "battery" below with the event generated on your laptop</comment> |
607 |
-<comment># For example, battery.* will match battery BAT0 00000080 00000001</comment> |
608 |
-event=battery.* |
609 |
-action=/etc/acpi/actions/pmg_switch_runlevel.sh %e |
610 |
-</pre> |
611 |
+</body> |
612 |
+</section> |
613 |
+<section> |
614 |
+<title>How does laptop-mode-tools work</title> |
615 |
+<body> |
616 |
|
617 |
<p> |
618 |
-Finally acpid has to be restarted to recognize the changes. |
619 |
+When running the <c>laptop_mode</c> service, the software will check in which |
620 |
+state your system is in. The states are defined as: |
621 |
</p> |
622 |
|
623 |
-<pre caption="Finishing runlevel switching with acpid"> |
624 |
-# <i>/etc/init.d/acpid restart</i> |
625 |
-</pre> |
626 |
+<ul> |
627 |
+ <li> |
628 |
+ <e>Battery</e>, in the configuration files using the <c>BATT_</c> prefix, is |
629 |
+ active when the system is running on battery power |
630 |
+ </li> |
631 |
+ <li> |
632 |
+ <e>AC</e>, in the configuration files using the <c>AC_</c> prefix, is active |
633 |
+ when the system is running on AC power |
634 |
+ </li> |
635 |
+ <li> |
636 |
+ <e>Laptop Mode</e>, in the configuration files using the <c>LM_</c> prefix, |
637 |
+ is active when <e>laptop mode</e> is enabled |
638 |
+ </li> |
639 |
+ <li> |
640 |
+ <e>No Laptop Mode</e>, in the configuration files using the <c>NOLM_</c> |
641 |
+ prefix, is active when <e>laptop mode</e> is disabled |
642 |
+ </li> |
643 |
+</ul> |
644 |
|
645 |
<p> |
646 |
-Give it a try: Plug AC in and out and watch syslog for the "Switching to AC |
647 |
-mode" or "Switching to battery mode" messages. See the <uri |
648 |
-link="#doc_chap8">Troubleshooting section</uri> if the script is not able to |
649 |
-detect the power source correctly. |
650 |
+The <c>AC/BATT_</c> and <c>LM/NOLM_</c> prefixes can be combined (so you can |
651 |
+have a <c>AC_LM_</c> prefix). |
652 |
</p> |
653 |
|
654 |
<p> |
655 |
-Due to the nature of the event mechanism, your laptop will boot into runlevel |
656 |
-<c>default</c> regardless of the AC/battery state. This is fine when running |
657 |
-from AC, but we'd like to boot into the battery runlevel otherwise. One |
658 |
-solution would be to add another entry to the boot loader with the parameter |
659 |
-<c>softlevel=battery</c>, but it's likely to forget choosing it. A better way |
660 |
-is faking an ACPI event in the end of the boot process and letting |
661 |
-<path>pmg_switch_runlevel.sh</path> script decide whether a runlevel change is |
662 |
-necessary. Create a <path>/etc/local.d/battery.start</path> file with the |
663 |
-following contents: |
664 |
-</p> |
665 |
- |
666 |
-<pre caption="Runlevel adjustment at boot time through local.d/battery.start"> |
667 |
-#!/bin/sh |
668 |
-<comment># Fake acpi event to switch runlevel if running on batteries</comment> |
669 |
-/etc/acpi/actions/pmg_switch_runlevel.sh "battery/battery" |
670 |
-</pre> |
671 |
+When the <c>laptop_mode</c> service is started, it will switch modes based on |
672 |
+events that occur (and of course based on the configuration settings). For |
673 |
+instance, the setting <c>ENABLE_LAPTOP_MODE_ON_BATTERY=1</c> will make sure that |
674 |
+the laptop mode tools switch to <e>laptop mode</e> when battery power is used. |
675 |
+If that is the case, then the settings starting with <c>LM_</c>, |
676 |
+<c>LM_BATT_</c>, <c>BATT_LM_</c> and <c>BATT_</c> will be used. |
677 |
+</p> |
678 |
|
679 |
<p> |
680 |
-Don't forget to mark the file as executable (<c>chmod +x |
681 |
-/etc/local.d/battery.start</c>). Prepared like this you can activate Power |
682 |
-Management policies for individual devices. |
683 |
+To make sure settings to not collide, it is not allowed to have overlapping |
684 |
+settigns. In the next example, the first set (for <c>CPU_MAXFREQ</c>) is valid, |
685 |
+but the second one (for <c>CPU_GOVERNOR</c>) isn't. |
686 |
</p> |
687 |
|
688 |
-</body> |
689 |
-</section> |
690 |
-</chapter> |
691 |
- |
692 |
-<chapter> |
693 |
-<title>CPU Power Management</title> |
694 |
-<section> |
695 |
-<body> |
696 |
+<pre caption="Colliding settings"> |
697 |
+<comment>## Valid set</comment> |
698 |
+BATT_CPU_MAXFREQ=fastest |
699 |
+LM_AC_CPU_MAXFREQ=fastest |
700 |
+NOLM_AC_CPU_MAXFREQ=fastest |
701 |
|
702 |
-<p> |
703 |
-Mobile processors can operate at different frequencies. Some allow changing |
704 |
-voltage as well. Most of the time your CPU doesn't need to run at full speed |
705 |
-and scaling it down will save much energy - often without any performance |
706 |
-decrease. |
707 |
-</p> |
708 |
+<comment>## Invalid set</comment> |
709 |
+BATT_CPU_MINFREQ=fastest |
710 |
+LM_AC_CPU_MINFREQ=fastest |
711 |
+<comment># The following includes AC and BATT, but BATT is already defined</comment> |
712 |
+NOLM_CPU_MINFREQ=fastest |
713 |
+</pre> |
714 |
|
715 |
</body> |
716 |
</section> |
717 |
<section> |
718 |
-<title>Some Technical Terms</title> |
719 |
+<title>Configuring CPU frequency management</title> |
720 |
<body> |
721 |
|
722 |
<p> |
723 |
-CPU frequency scaling brings up some technical terms that might be unknown to |
724 |
-you. Here's a quick introduction. |
725 |
+The support for CPU frequency management in the laptop mode tools allows |
726 |
+switching frequencies. It supports setting the CPU frequency governor, minimum |
727 |
+frequency and maximum frequency. The configuration file used here is |
728 |
+<path>/etc/laptop-mode/conf.d/cpufreq.conf</path>. |
729 |
</p> |
730 |
|
731 |
<p> |
732 |
-First of all, the kernel has to be able to change the processor's frequency. |
733 |
-The <b>CPUfreq processor driver</b> knows the commands to do it on your CPU. |
734 |
-Thus it's important to choose the right one in your kernel. You should already |
735 |
-have done it above. Once the kernel knows how to change frequencies, it has to |
736 |
-know which frequency it should set. This is done according to the <b>policy</b> |
737 |
-which consists of a <b>CPUfreq policy</b> and a <b>governor</b>. A CPUfreq |
738 |
-policy are just two numbers which define a range the frequency has to stay |
739 |
-between - minimal and maximal frequency. The governor now decides which of the |
740 |
-available frequencies in between minimal and maximal frequency to choose. For |
741 |
-example, the <b>powersave governor</b> always chooses the lowest frequency |
742 |
-available, the <b>performance governor</b> the highest one. The <b>userspace |
743 |
-governor</b> makes no decision but chooses whatever the user (or a program in |
744 |
-userspace) wants - which means it reads the frequency from |
745 |
-<path>/sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed</path>. |
746 |
+The <e>CPU frequency governor</e> is a kernel-level policy that defines how the |
747 |
+kernel will select the CPU frequency. We already selected the governors we want |
748 |
+to use in the kernel configuration earlier. Let's recap: |
749 |
</p> |
750 |
|
751 |
+<ul> |
752 |
+ <li> |
753 |
+ <c>performance</c> always picks the highest frequency |
754 |
+ </li> |
755 |
+ <li> |
756 |
+ <c>powersave</c> always picks the lowest frequency |
757 |
+ </li> |
758 |
+ <li> |
759 |
+ <c>userspace</c> does not pick anything, but let the user decide (or any |
760 |
+ process that the user is running that will decide for the user) |
761 |
+ </li> |
762 |
+ <li> |
763 |
+ <c>ondemand</c> will scale the CPU frequency up to the highest frequency |
764 |
+ when load is available |
765 |
+ </li> |
766 |
+ <li> |
767 |
+ <c>conservative</c> will scale the CPU frequency up gradually when load is |
768 |
+ available |
769 |
+ </li> |
770 |
+</ul> |
771 |
+ |
772 |
<p> |
773 |
-This doesn't sound like dynamic frequency changes yet and in fact it isn't. |
774 |
-Dynamics however can be accomplished with various approaches. For example, the |
775 |
-<b>ondemand governor</b> makes its decisions depending on the current CPU load. |
776 |
-The same is done by various userland tools like <c>cpudyn</c>, <c>cpufreqd</c>, |
777 |
-<c>powernowd</c> and many more. ACPI events can be used to enable or disable |
778 |
-dynamic frequency changes depending on power source. |
779 |
+When switching between AC or battery, or (no) laptop mode, the appropriate |
780 |
+governor (as well as its minimum and maximum frequency) is selected. |
781 |
</p> |
782 |
|
783 |
</body> |
784 |
</section> |
785 |
<section> |
786 |
-<title>Setting The Frequency</title> |
787 |
+<title>Configuring display brightness</title> |
788 |
<body> |
789 |
|
790 |
<p> |
791 |
-Decreasing CPU speed and voltage has two advantages: On the one hand less |
792 |
-energy is consumed, on the other hand there is thermal improvement as your |
793 |
-system doesn't get as hot as running on full speed. The main disadvantage is |
794 |
-obviously the loss of performance. Decreasing processor speed is a trade off |
795 |
-between performance loss and energy saving. |
796 |
+With <path>/etc/laptop-mode/conf.d/lcd-brightness.conf</path>, you can have the |
797 |
+laptop mode tools govern the brightness of your LCD screen. |
798 |
</p> |
799 |
|
800 |
-<note> |
801 |
-Not every laptop supports frequency scaling. If unsure, have a look at the list |
802 |
-of supported processors in the <uri link="#doc_chap8">Troubleshooting</uri> |
803 |
-section to verify yours is supported. |
804 |
-</note> |
805 |
- |
806 |
<p> |
807 |
-It's time to test whether CPU frequency changing works. Let's install another |
808 |
-tool: <c>sys-power/cpufrequtils</c>. |
809 |
+The file currently uses the <path>/proc/acpi/video/VID/LCD/brightness</path> |
810 |
+file to set brightness values. Recent kernels do not provide this anymore - |
811 |
+you will need to adjust this to <path>/sys/class/backlight/acpi_video0/brightness</path> |
812 |
+instead. |
813 |
</p> |
814 |
|
815 |
-<pre caption="Checking CPU frequency"> |
816 |
-# <i>emerge cpufrequtils</i> |
817 |
-# <i>cpufreq-info</i> |
818 |
-</pre> |
819 |
- |
820 |
<p> |
821 |
-Here is an example output: |
822 |
+The values you can use are between 0 and 15, with 0 being the lowest brightness |
823 |
+value. |
824 |
</p> |
825 |
|
826 |
-<pre caption="Sample output from cpufreq-info"> |
827 |
-cpufrequtils 0.3: cpufreq-info (C) Dominik Brodowski 2004 |
828 |
-Report errors and bugs to linux@×××××.de, please. |
829 |
-analyzing CPU 0: |
830 |
- driver: centrino |
831 |
- CPUs which need to switch frequency at the same time: 0 |
832 |
- hardware limits: 600 MHz - 1.40 GHz |
833 |
- available frequency steps: 600 MHz, 800 MHz, 1000 MHz, 1.20 GHz, 1.40 GHz |
834 |
- available cpufreq governors: conservative, ondemand, powersave, userspace, performance |
835 |
- current policy: frequency should be within 924 MHz and 1.40 GHz. |
836 |
- The governor "performance" may decide which speed to use |
837 |
- within this range. |
838 |
- current CPU frequency is 1.40 GHz. |
839 |
-</pre> |
840 |
+</body> |
841 |
+</section> |
842 |
+<section> |
843 |
+<title>Configuring other services</title> |
844 |
+<body> |
845 |
|
846 |
<p> |
847 |
-Now play around with <c>cpufreq-set</c> to make sure frequency switching works. |
848 |
-Run <c>cpufreq-set -g ondemand</c> for example to activate the ondemand |
849 |
-governor and verify the change with <c>cpufreq-info</c>. If it doesn't work as |
850 |
-expected, you might find help in the <uri link="#doc_chap8">Troubleshooting |
851 |
-section</uri> in the end of this guide. |
852 |
+An interesting feature of <c>laptop-mode-tools</c> is to support reloading |
853 |
+particular services (like the system logger) after switching its configuration |
854 |
+file. This is handled through |
855 |
+<path>/etc/laptop-mode/conf.d/configuration-file-control.conf</path>. |
856 |
</p> |
857 |
|
858 |
<p> |
859 |
-<c>cpufrequtils</c> can operate in an automatic mode (when you use the |
860 |
-<b>ondemand</b> governor), you can also switch to the <b>userspace</b> governor |
861 |
-if you want to manually set a specific speed. You can also statically set your |
862 |
-CPU to its highest or lowest frequency by using the <b>performance</b> |
863 |
-and <b>powersave</b> governors, respectively. |
864 |
-</p> |
865 |
- |
866 |
-<pre caption="Changing CPU speeds"> |
867 |
-<comment>(Set the highest available frequency)</comment> |
868 |
-# <i>cpufreq-set -g performance</i> |
869 |
-<comment>(Set the lowest available frequency)</comment> |
870 |
-# <i>cpufreq-set -g powersave</i> |
871 |
-<comment>(Set a specific frequency)</comment> |
872 |
-# <i>cpufreq-set -g userspace</i> |
873 |
-# <i>cpufreq-set -f 2.00ghz</i> |
874 |
-</pre> |
875 |
+If enabled, the <c>laptop_mode</c> application will switch the configuration |
876 |
+file(s) of the mentioned services with the same file, but suffixed with |
877 |
+<path>-nolm-ac</path>, <path>-lm-ac</path> or <path>-batt</path>. It willl then |
878 |
+signal or reload the appropriate services so they can use the new configuration |
879 |
+file. |
880 |
+</p> |
881 |
|
882 |
</body> |
883 |
</section> |
884 |
+</chapter> |
885 |
+ |
886 |
+<chapter> |
887 |
+<title>Using cpufreqd</title> |
888 |
<section> |
889 |
-<title>Other CPU Speed Utilities</title> |
890 |
+<title>Installation</title> |
891 |
<body> |
892 |
|
893 |
<p> |
894 |
-While <c>cpufrequtils</c> may be the best all-around program, there are some |
895 |
-other choices available in Portage. The following table gives a quick overview |
896 |
-of available CPU speed utilities. It's roughly separated in three categories |
897 |
-<b>kernel</b> for approaches that only need kernel support, <b>daemon</b> for |
898 |
-programs that run in the background and <b>graphical</b> for programs that |
899 |
-provide a GUI for easy configuration and changes. |
900 |
+The <c>cpufreqd</c> application allows you to manage CPU frequencies in a more |
901 |
+granular approach then what <c>laptop-mode-tools</c> supports. But before we |
902 |
+dive into the installation of <c>cpufreqd</c>, let's first look at the USE flags |
903 |
+it supports. |
904 |
</p> |
905 |
|
906 |
<table> |
907 |
<tr> |
908 |
- <th>Name</th> |
909 |
- <th>Category</th> |
910 |
- <th>Switch decision</th> |
911 |
- <th>Kernel governors</th> |
912 |
- <th>Further governors</th> |
913 |
- <th>Comments</th> |
914 |
+ <th>USE flag</th> |
915 |
+ <th>Description</th> |
916 |
+ <th>Suggested when...</th> |
917 |
</tr> |
918 |
<tr> |
919 |
- <ti>'ondemand' governor</ti> |
920 |
- <ti>Kernel</ti> |
921 |
- <ti>CPU load</ti> |
922 |
- <ti>N.A.</ti> |
923 |
- <ti>N.A.</ti> |
924 |
+ <ti>acpi</ti> |
925 |
<ti> |
926 |
- Chooses maximal frequency on CPU load and slowly steps down when the CPU is |
927 |
- idle. Further tuning through files in |
928 |
- <path>/sys/devices/system/cpu/cpu0/cpufreq/ondemand/</path>. Still requires |
929 |
- userland tools (programs, scripts) if governor switching or similar is |
930 |
- desired. |
931 |
+ Enable support for ACPI, allowing <c>cpufreqd</c> to be notified about |
932 |
+ specific events as well as govern power through the ACPI interface |
933 |
</ti> |
934 |
+ <ti>your laptop is not too old (~ year 2003 and later)</ti> |
935 |
</tr> |
936 |
<tr> |
937 |
- <ti>'conservative' governor</ti> |
938 |
- <ti>Kernel</ti> |
939 |
- <ti>CPU load</ti> |
940 |
- <ti>N.A.</ti> |
941 |
- <ti>N.A.</ti> |
942 |
+ <ti>apm</ti> |
943 |
<ti> |
944 |
- Unlike the ondemand governor, conversative doesn't jump to maximum |
945 |
- frequency when CPU load is high, but increases the frequency step by step. |
946 |
- Further tuning through files in |
947 |
- <path>/sys/devices/system/cpu/cpu0/cpufreq/ondemand/</path>. Still requires |
948 |
- userland tools (programs, scripts) if governor switching or similar is |
949 |
- desired. |
950 |
+ Enable support for APM, allowing <c>cpufreqd</c> to be notified about |
951 |
+ specific events as wel as govern power through the APM interface |
952 |
</ti> |
953 |
+ <ti>your laptop is very old</ti> |
954 |
</tr> |
955 |
<tr> |
956 |
- <ti><uri link="http://mnm.uib.es/~gallir/cpudyn/">cpudyn</uri></ti> |
957 |
- <ti>Daemon</ti> |
958 |
- <ti>CPU load</ti> |
959 |
- <ti>Performance, powersave</ti> |
960 |
- <ti>Dynamic</ti> |
961 |
+ <ti>lm_sensors</ti> |
962 |
<ti> |
963 |
- Also supports disk standby - notice however that <e>laptop mode</e> in most |
964 |
- cases will do a better job. |
965 |
+ Enable support for the Linux hardware sensors (through |
966 |
+ <c>sys-apps/lm_sensors</c>), allowing to switch profiles based on hardware |
967 |
+ sensor results |
968 |
</ti> |
969 |
-</tr> |
970 |
-<tr> |
971 |
- <ti><uri link="http://sourceforge.net/projects/cpufreqd/">cpufreqd</uri></ti> |
972 |
- <ti>Daemon</ti> |
973 |
- <ti>Battery state, CPU load, temperature, running programs and more</ti> |
974 |
- <ti>All available</ti> |
975 |
- <ti>None</ti> |
976 |
<ti> |
977 |
- Sophisticated (but somewhat complicated) setup. Extendible through plugins |
978 |
- like sensor monitoring (lm_sensors) or coordinating some NVidia based |
979 |
- graphics card memory and core. Cpufreqd is SMP aware and can optionally be |
980 |
- controlled manually at runtime. |
981 |
+ you want to use advanced events through lm_sensors |
982 |
</ti> |
983 |
</tr> |
984 |
<tr> |
985 |
+ <ti>nforce2</ti> |
986 |
<ti> |
987 |
- <uri link="http://www.deater.net/john/powernowd.html">powernowd</uri> |
988 |
+ Enable support for NForce, allowing <c>cpufreqd</c> to change the NForce FSB |
989 |
+ clock and video card frequency |
990 |
</ti> |
991 |
- <ti>Daemon</ti> |
992 |
- <ti>CPU load</ti> |
993 |
- <ti>None</ti> |
994 |
- <ti>Passive, sine, aggressive</ti> |
995 |
<ti> |
996 |
- Supports SMP. |
997 |
+ you have an NVidia graphical card based on the NForce chipset |
998 |
</ti> |
999 |
</tr> |
1000 |
<tr> |
1001 |
+ <ti>nvidia</ti> |
1002 |
<ti> |
1003 |
- <uri |
1004 |
- link="http://projects.simpledesigns.com.pl/project/ncpufreqd/">ncpufreqd</uri> |
1005 |
- </ti> |
1006 |
- <ti>Daemon</ti> |
1007 |
- <ti>Temperature</ti> |
1008 |
- <ti>None</ti> |
1009 |
- <ti>Powersave, performance</ti> |
1010 |
- <ti> |
1011 |
- Toggles the used governor between performance and powersave depending on |
1012 |
- system temperature. Very useful on laptops with notorious heat problems. |
1013 |
+ Enable support for NVidia graphical card configuration (through the NVidia |
1014 |
+ <e>nvclock</e> interface), allowing <c>cpufreqd</c> to change the video card |
1015 |
+ frequency of NVidia graphical cards |
1016 |
</ti> |
1017 |
-</tr> |
1018 |
-<tr> |
1019 |
- <ti><uri link="http://www.goop.org/~jeremy/speedfreq/">speedfreq</uri></ti> |
1020 |
- <ti>Daemon</ti> |
1021 |
- <ti>CPU load</ti> |
1022 |
- <ti>None</ti> |
1023 |
- <ti>Dynamic, powersave, performance, fixed speed</ti> |
1024 |
<ti> |
1025 |
- Easy to configure with a nice client/server interface. Requires a 2.6 |
1026 |
- kernel. Unmaintained, broken and thus removed from Portage. Please switch |
1027 |
- to cpufreqd if you're still using it. |
1028 |
+ you have an NVidia graphical card |
1029 |
</ti> |
1030 |
</tr> |
1031 |
<tr> |
1032 |
- <ti><uri link="http://cpuspeedy.sourceforge.net/">gtk-cpuspeedy</uri></ti> |
1033 |
- <ti>Graphical</ti> |
1034 |
- <ti>None</ti> |
1035 |
- <ti>None</ti> |
1036 |
- <ti>None</ti> |
1037 |
+ <ti>pmu</ti> |
1038 |
<ti> |
1039 |
- Gnome application, a graphical tool to set CPU frequency manually. It does |
1040 |
- not offer any automation. |
1041 |
+ Enable the Power Management Unit plug-in of <c>cpufreqd</c>. This allows the |
1042 |
+ software to poll the Linux kernel Power Supply interface, getting more |
1043 |
+ detailed information on battery charge. |
1044 |
</ti> |
1045 |
-</tr> |
1046 |
-<tr> |
1047 |
- <ti>klaptopdaemon</ti> |
1048 |
- <ti>Graphical</ti> |
1049 |
- <ti>Battery state</ti> |
1050 |
- <ti>All available</ti> |
1051 |
- <ti>None</ti> |
1052 |
<ti> |
1053 |
- KDE only, 'ondemand' governor required for dynamic frequency scaling. |
1054 |
+ your laptop does not support ACPI or APM |
1055 |
</ti> |
1056 |
</tr> |
1057 |
</table> |
1058 |
|
1059 |
<p> |
1060 |
-While adjusting the frequency to the current load looks simple at a first |
1061 |
-glance, it's not such a trivial task. A bad algorithm can cause switching |
1062 |
-between two frequencies all the time or wasting energy when setting frequency |
1063 |
-to an unnecessary high level. |
1064 |
+The USE flags <c>acpi</c>, <c>apm</c> and <c>pmu</c> overlap, so you should only |
1065 |
+have one active. If your laptop is sufficiently recent, <c>acpi</c> is your best |
1066 |
+bet. If not, <c>apm</c> offers all that is needed. When even APM isn't |
1067 |
+supported, you can try <c>pmu</c>. |
1068 |
</p> |
1069 |
|
1070 |
<p> |
1071 |
-Which one to choose? If you have no idea about it, try <c>cpufreqd</c>: |
1072 |
+With the USE flags configured, it is time to install <c>cpufreqd</c>. |
1073 |
</p> |
1074 |
|
1075 |
<pre caption="Installing cpufreqd"> |
1076 |
# <i>emerge cpufreqd</i> |
1077 |
</pre> |
1078 |
|
1079 |
-<p> |
1080 |
-<c>cpufreqd</c> can be configured by editing <path>/etc/cpufreqd.conf</path>. |
1081 |
-The default one that ships with cpufreqd may look a bit confusing. I recommend |
1082 |
-replacing it with the one from former Gentoo developer Henrik Brix Andersen |
1083 |
-(see below). Please notice that you need cpufreqd-2.0.0 or later. Earlier |
1084 |
-versions have a different syntax for the config file. |
1085 |
-</p> |
1086 |
- |
1087 |
-<pre caption="/etc/cpufreqd.conf (cpufreqd-2.0.0 and later)"> |
1088 |
-[General] |
1089 |
-pidfile=/var/run/cpufreqd.pid |
1090 |
-poll_interval=3 |
1091 |
-enable_plugins=acpi_ac, acpi_battery |
1092 |
-enable_remote=1 |
1093 |
-remote_group=wheel |
1094 |
-verbosity=5 |
1095 |
-[/General] |
1096 |
- |
1097 |
-[Profile] |
1098 |
-name=ondemand |
1099 |
-minfreq=0% |
1100 |
-maxfreq=100% |
1101 |
-policy=ondemand |
1102 |
-[/Profile] |
1103 |
- |
1104 |
-[Profile] |
1105 |
-name=conservative |
1106 |
-minfreq=0% |
1107 |
-maxfreq=100% |
1108 |
-policy=conservative |
1109 |
-[/Profile] |
1110 |
- |
1111 |
-[Profile] |
1112 |
-name=powersave |
1113 |
-minfreq=0% |
1114 |
-maxfreq=100% |
1115 |
-policy=powersave |
1116 |
-[/Profile] |
1117 |
- |
1118 |
-[Profile] |
1119 |
-name=performance |
1120 |
-minfreq=0% |
1121 |
-maxfreq=100% |
1122 |
-policy=performance |
1123 |
-[/Profile] |
1124 |
- |
1125 |
-[Rule] |
1126 |
-name=battery |
1127 |
-ac=off |
1128 |
-profile=conservative |
1129 |
-[/Rule] |
1130 |
- |
1131 |
-[Rule] |
1132 |
-name=battery_low |
1133 |
-ac=off |
1134 |
-battery_interval=0-10 |
1135 |
-profile=powersave |
1136 |
-[/Rule] |
1137 |
- |
1138 |
-[Rule] |
1139 |
-name=ac |
1140 |
-ac=on |
1141 |
-profile=ondemand |
1142 |
-[/Rule] |
1143 |
-</pre> |
1144 |
- |
1145 |
-<p> |
1146 |
-Now you can start the cpufreqd daemon. Add it to the <c>default</c> and |
1147 |
-<c>battery</c> runlevel as well. |
1148 |
-</p> |
1149 |
- |
1150 |
-<pre caption="Starting cpufreqd"> |
1151 |
-# <i>rc-update add cpufreqd default battery</i> |
1152 |
-# <i>/etc/init.d/cpufreqd start</i> |
1153 |
-</pre> |
1154 |
- |
1155 |
-<p> |
1156 |
-Sometimes it can be desirable to select another policy than the daemon chooses, |
1157 |
-for example when battery power is low, but you know that AC will be available |
1158 |
-soon. In that case you can turn on cpufreqd's manual mode with <c>cpufreqd-set |
1159 |
-manual</c> and select one of your configured policies (as listed by |
1160 |
-<c>cpufreqd-get</c>). You can leave manual mode by executing <c>cpufreqd-set |
1161 |
-dynamic</c>. |
1162 |
-</p> |
1163 |
- |
1164 |
-<warn> |
1165 |
-Do not run more than one of the above programs at the same time. It may cause |
1166 |
-confusion like switching between two frequencies all the time. |
1167 |
-</warn> |
1168 |
- |
1169 |
</body> |
1170 |
</section> |
1171 |
<section> |
1172 |
-<title>Verifying the result</title> |
1173 |
+<title>Configuration</title> |
1174 |
<body> |
1175 |
|
1176 |
<p> |
1177 |
-The last thing to check is that your new policies do a good job. An easy way to |
1178 |
-do so is monitoring CPU speed while working with your laptop: |
1179 |
-</p> |
1180 |
- |
1181 |
-<pre caption="Monitoring CPU speed"> |
1182 |
-# <i>watch grep \"cpu MHz\" /proc/cpuinfo</i> |
1183 |
-</pre> |
1184 |
- |
1185 |
-<p> |
1186 |
-If <path>/proc/cpuinfo</path> doesn't get updated (see <uri |
1187 |
-link="#doc_chap8">Troubleshooting</uri>), monitor the CPU frequency with |
1188 |
-<c>sys-apps/x86info</c>: |
1189 |
+The <c>cpufreqd</c> application monitors the status of the system through |
1190 |
+several plugins. Based on the feedback it receives from those plugins, it will |
1191 |
+adjust the policy used to govern the CPU frequency. |
1192 |
</p> |
1193 |
|
1194 |
-<pre caption="Alternative CPU speed monitoring"> |
1195 |
-# <i>watch x86info -mhz</i> |
1196 |
-</pre> |
1197 |
- |
1198 |
<p> |
1199 |
-Depending on your setup, CPU speed should increase on heavy load, decrease on |
1200 |
-no activity or just stay at the same level. When using <c>cpufreqd</c> and |
1201 |
-verbosity set to 5 or higher in <path>cpufreqd.conf</path> you'll get |
1202 |
-additional information about what's happening reported to <c>syslog</c>. |
1203 |
+<c>cpufreqd</c> can be configured by editing <path>/etc/cpufreqd.conf</path>. It |
1204 |
+contains three different sections: |
1205 |
</p> |
1206 |
|
1207 |
-</body> |
1208 |
-</section> |
1209 |
-</chapter> |
1210 |
- |
1211 |
-<chapter> |
1212 |
-<title>LCD Power Management</title> |
1213 |
-<section> |
1214 |
-<body> |
1215 |
+<ol> |
1216 |
+ <li> |
1217 |
+ The <c>[General]...[/General]</c> section contains general configuration |
1218 |
+ information |
1219 |
+ </li> |
1220 |
+ <li> |
1221 |
+ The <c>[Profile]...[/Profile]</c> section defines the policies that the |
1222 |
+ <c>cpufreqd</c> daemon can switch to. The section is very similar to the |
1223 |
+ information you use when manually setting the CPU frequency policy using |
1224 |
+ <c>cpufreq-set</c>. |
1225 |
+ </li> |
1226 |
+ <li> |
1227 |
+ The <c>[Rule]...[/Rule]</c> section is the work-horse of the <c>cpufreqd</c> |
1228 |
+ daemon, defining when the daemon decides to switch to a different profile. |
1229 |
+ </li> |
1230 |
+</ol> |
1231 |
|
1232 |
<p> |
1233 |
-As you can see in <uri link="#doc_chap1_fig1">figure 1.1</uri>, the LCD |
1234 |
-display consumes the biggest part of energy (might not be the case for |
1235 |
-non-mobile CPU's). Thus it's quite important not only to shut the display off |
1236 |
-when not needed, but also to reduce it's backlight if possible. Most laptops |
1237 |
-offer the possibility to control the backlight dimming. |
1238 |
+Let's take a quick look at an example rule. |
1239 |
</p> |
1240 |
|
1241 |
-</body> |
1242 |
-</section> |
1243 |
-<section> |
1244 |
-<title>Standby settings</title> |
1245 |
-<body> |
1246 |
+<pre caption="Sample cpufreqd rule"> |
1247 |
+[Profile] |
1248 |
+name=On Demand High |
1249 |
+minfreq=40% |
1250 |
+maxfreq=100% |
1251 |
+policy=ondemand |
1252 |
+[/Profile] |
1253 |
|
1254 |
-<p> |
1255 |
-The first thing to check is the standby/suspend/off timings of the display. As |
1256 |
-this depends heavily on your windowmanager, I'll let you figure it out |
1257 |
-yourself. Just two common places: Blanking the terminal can be done with |
1258 |
-<c>setterm -blank <number-of-minutesM></c>, <c>setterm -powersave on</c> |
1259 |
-and <c>setterm -powerdown <number-of-minutesM></c>. For X.org, modify |
1260 |
-<path>/etc/X11/xorg.conf</path> similar to this: |
1261 |
-</p> |
1262 |
- |
1263 |
-<pre caption="LCD suspend settings in X.org"> |
1264 |
-Section "ServerFlags" |
1265 |
- Option "blank time" "5" <comment># Blank the screen after 5 minutes (Fake)</comment> |
1266 |
- Option "standby time" "10" <comment># Turn off screen after 10 minutes (DPMS)</comment> |
1267 |
- Option "suspend time" "20" <comment># Full suspend after 20 minutes</comment> |
1268 |
- Option "off time" "30" <comment># Turn off after half an hour</comment> |
1269 |
- [...] |
1270 |
-EndSection |
1271 |
- |
1272 |
-[...] |
1273 |
- |
1274 |
-Section "Monitor" |
1275 |
- Identifier [...] |
1276 |
- Option "DPMS" |
1277 |
- [...] |
1278 |
-EndSection |
1279 |
+[Rule] |
1280 |
+name=AC Off - High Power |
1281 |
+ac=off |
1282 |
+battery_interval=70-100 |
1283 |
+profile=On Demand High |
1284 |
+[/Rule] |
1285 |
</pre> |
1286 |
|
1287 |
-</body> |
1288 |
-</section> |
1289 |
-<section> |
1290 |
-<title>Backlight dimming</title> |
1291 |
-<body> |
1292 |
- |
1293 |
<p> |
1294 |
-Probably more important is the backlight dimming. If you have access to the |
1295 |
-dimming settings via a tool, write a small script that dims the backlight in |
1296 |
-battery mode and place it in your <c>battery</c> runlevel. The following script |
1297 |
-should work on most IBM Thinkpads and Toshiba laptops. You've got to enable the |
1298 |
-appropriate option in your kernel (IBM Thinkpads only). For Toshiba laptops, |
1299 |
-install <c>sys-power/acpitool</c> and skip configuration of <c>thinkpad_acpi</c> |
1300 |
-(formerly called <c>ibm_acpi</c>) as described below. |
1301 |
-</p> |
1302 |
- |
1303 |
-<warn> |
1304 |
-Support for setting brightness is marked experimental in thinkpad_acpi. It |
1305 |
-accesses hardware directly and may cause severe harm to your system. Please |
1306 |
-read the <uri link="http://ibm-acpi.sourceforge.net/">thinkpad_acpi |
1307 |
-website</uri> |
1308 |
-</warn> |
1309 |
- |
1310 |
-<p> |
1311 |
-To be able to set the brightness level, the thinkpad_acpi module has to be |
1312 |
-loaded with the experimental parameter. |
1313 |
-</p> |
1314 |
- |
1315 |
-<pre caption="Automatically loading the thinkpad_acpi module"> |
1316 |
-<comment>(Please read the warnings above before doing this!)</comment> |
1317 |
- |
1318 |
-# <i>echo "options thinkpad_acpi experimental=1" >> /etc/modprobe.d/thinkpad_acpi</i> |
1319 |
-# <i>update-modules</i> |
1320 |
-# <i>nano /etc/conf.d/modules</i> |
1321 |
-<comment># Autoload the thinkpad_acpi module</comment> |
1322 |
-modules_2_6="thinkpad_acpi" |
1323 |
-<comment># Parameters for the thinkpad_acpi module</comment> |
1324 |
-modules_thinkpad_acpi_args_2_6="experimental=1" |
1325 |
- |
1326 |
-# <i>modprobe thinkpad_acpi</i> |
1327 |
-</pre> |
1328 |
+In the above example, <c>cpufreqd</c> will switch the system to the <e>On Demand |
1329 |
+High</e> profile (also shown in the above excerpt). This profile by itself uses |
1330 |
+the <c>ondemand</c> governor with a minimum frequency of 40% (iow, a CPU of 2Ghz |
1331 |
+will have by this policy a minimum frequency of 800Mhz). |
1332 |
+</p> |
1333 |
|
1334 |
<p> |
1335 |
-This should work without error messages and a file |
1336 |
-<path>/proc/acpi/ibm/brightness</path> should be created after loading the |
1337 |
-module. An init script will take care of choosing the brightness according to |
1338 |
-the power source. |
1339 |
+As you can see, the <c>cpufreqd</c> application can offer a more granular |
1340 |
+approach on CPU frequency scaling. But not only that, you can tweak the CPU |
1341 |
+frequency scaling based on various other metrics available. The default |
1342 |
+configuration offers a sample rule for when you watch a movie, where you want |
1343 |
+maximum performance, unless the CPU temperature is getting too high. |
1344 |
</p> |
1345 |
|
1346 |
-<pre caption="/etc/conf.d/lcd-brightness"> |
1347 |
-<comment># See /proc/acpi/ibm/brightness for available values</comment> |
1348 |
-<comment># Please read /usr/src/linux/Documentation/thinkpad-acpi.txt</comment> |
1349 |
- |
1350 |
-<comment># brightness level in ac mode. Default is 7.</comment> |
1351 |
-BRIGHTNESS_AC=7 |
1352 |
- |
1353 |
-<comment># brightness level in battery mode. Default is 4.</comment> |
1354 |
-BRIGHTNESS_BATTERY=4 |
1355 |
-</pre> |
1356 |
- |
1357 |
-<pre caption="/etc/init.d/lcd-brightness"> |
1358 |
-#!/sbin/runscript |
1359 |
- |
1360 |
-set_brightness() { |
1361 |
- if on_ac_power |
1362 |
- then |
1363 |
- LEVEL=${BRIGHTNESS_AC:-7} |
1364 |
- else |
1365 |
- LEVEL=${BRIGHTNESS_BATTERY:-4} |
1366 |
- fi |
1367 |
- |
1368 |
- if [ -f /proc/acpi/ibm/brightness ] |
1369 |
- then |
1370 |
- ebegin "Setting LCD brightness" |
1371 |
- echo "level ${LEVEL}" > /proc/acpi/ibm/brightness |
1372 |
- eend $? |
1373 |
- elif [[ -e /usr/bin/acpitool && -n $(acpitool -T | grep "LCD brightness") ]] |
1374 |
- then |
1375 |
- ebegin "Setting LCD brightness" |
1376 |
- acpitool -l $LEVEL >/dev/null || ewarn "Unable to set lcd brightness" |
1377 |
- eend $? |
1378 |
- else |
1379 |
- ewarn "Setting LCD brightness is not supported." |
1380 |
- ewarn "For IBM Thinkpads, check that thinkpad_acpi is loaded into the kernel" |
1381 |
- ewarn "For Toshiba laptops, you've got to install sys-power/acpitool" |
1382 |
- fi |
1383 |
-} |
1384 |
- |
1385 |
-start() { |
1386 |
- set_brightness |
1387 |
-} |
1388 |
- |
1389 |
-stop () { |
1390 |
- set_brightness |
1391 |
-} |
1392 |
-</pre> |
1393 |
- |
1394 |
<p> |
1395 |
-When done, make sure brightness is adjusted automatically by adding it to the |
1396 |
-battery runlevel. |
1397 |
+When you have configured <c>cpufreqd</c>, it is time to start it (and make sure |
1398 |
+the service is loaded automatically). Make sure that CPU frequency handling by |
1399 |
+other tools (like <c>laptop-mode-tools</c>) is disabled! |
1400 |
</p> |
1401 |
|
1402 |
-<pre caption="Enabling automatic brightness adjustment"> |
1403 |
-# <i>chmod +x /etc/init.d/lcd-brightness</i> |
1404 |
-# <i>rc-update add lcd-brightness battery</i> |
1405 |
-# <i>rc</i> |
1406 |
+<pre caption="Starting cpufreqd"> |
1407 |
+# <i>rc-service add cpufreqd default</i> |
1408 |
+# <i>/etc/init.d/cpufreqd start</i> |
1409 |
</pre> |
1410 |
|
1411 |
</body> |
1412 |
@@ -993,722 +643,40 @@ |
1413 |
</chapter> |
1414 |
|
1415 |
<chapter> |
1416 |
-<title>Disk Power Management</title> |
1417 |
-<section> |
1418 |
-<body> |
1419 |
- |
1420 |
-<p> |
1421 |
-Hard disks consume less energy in sleep mode. Therefore it makes sense to |
1422 |
-activate power saving features whenever the hard disk is not used for a certain |
1423 |
-amount of time. I'll show you two alternative possibilities to do it. First, |
1424 |
-laptop-mode will save most energy due to several measures which prevent or at |
1425 |
-least delay write accesses. The drawback is that due to the delayed write |
1426 |
-accesses a power outage or kernel crash will be more dangerous for data loss. |
1427 |
-If you don't like this, you have to make sure that there are no processes which |
1428 |
-write to your hard disk frequently. Afterwards you can enable power saving |
1429 |
-features of your hard disk with <c>hdparm</c> as the second alternative. |
1430 |
-</p> |
1431 |
- |
1432 |
-</body> |
1433 |
-</section> |
1434 |
+<title>Resources</title> |
1435 |
<section> |
1436 |
-<title>Increasing idle time - laptop-mode</title> |
1437 |
+<title>Tools</title> |
1438 |
<body> |
1439 |
|
1440 |
-<p> |
1441 |
-Recent 2.6 kernels include the so-called <c>laptop-mode</c>. When activated, |
1442 |
-dirty buffers are written to disk on read calls or after 10 minutes (instead of |
1443 |
-30 seconds). This minimizes the time the hard disk needs to be spun up. |
1444 |
-</p> |
1445 |
- |
1446 |
-<pre caption="Automated start of laptop-mode"> |
1447 |
-# <i>emerge laptop-mode-tools</i> |
1448 |
-</pre> |
1449 |
- |
1450 |
-<p> |
1451 |
-<c>laptop-mode-tools</c> has its configuration file in |
1452 |
-<path>/etc/laptop-mode/laptop-mode.conf</path>. Adjust it the way you like it, |
1453 |
-it's well commented. Run <c>rc-update add laptop_mode battery</c> to start it |
1454 |
-automatically. |
1455 |
-</p> |
1456 |
- |
1457 |
-<p> |
1458 |
-Recent versions (1.11 and later) of laptop-mode-tools include a new tool |
1459 |
-<c>lm-profiler</c>. It will monitor your system's disk usage and running |
1460 |
-network services and suggests to disable unneeded ones. You can either disable |
1461 |
-them through laptop-mode-tools builtin runlevel support (which will be reverted |
1462 |
-by Gentoo's <c>/sbin/rc</c>) or use your <c>default</c>/<c>battery</c> |
1463 |
-runlevels (recommended). |
1464 |
-</p> |
1465 |
- |
1466 |
-<pre caption="Sample output from running lm-profiler"> |
1467 |
-# <i>lm-profiler</i> |
1468 |
-Profiling session started. |
1469 |
-Time remaining: 600 seconds |
1470 |
-[4296896.602000] amarokapp |
1471 |
-Time remaining: 599 seconds |
1472 |
-[4296897.714000] sort |
1473 |
-[4296897.970000] mv |
1474 |
-Time remaining: 598 seconds |
1475 |
-Time remaining: 597 seconds |
1476 |
-[4296900.482000] reiserfs/0 |
1477 |
-</pre> |
1478 |
- |
1479 |
-<p> |
1480 |
-After profiling your system for ten minutes, lm-profiler will present a list of |
1481 |
-services which might have caused disk accesses during that time. |
1482 |
-</p> |
1483 |
- |
1484 |
-<pre caption="lm-profiler suggests to disable some services"> |
1485 |
-Program: "atd" |
1486 |
-Reason: standard recommendation (program may not be running) |
1487 |
-Init script: /etc/init.d/atd (GUESSED) |
1488 |
- |
1489 |
-Do you want to disable this service in battery mode? [y/N]: <i>n</i> |
1490 |
-</pre> |
1491 |
- |
1492 |
-<p> |
1493 |
-To disable atd as suggested in the example above, you would run <c>rc-update |
1494 |
-del atd battery</c>. Be careful not to disable services that are needed for |
1495 |
-your system to run properly - <c>lm-profiler</c> is likely to generate some |
1496 |
-false positives. Do not disable a service if you are unsure whether it's |
1497 |
-needed. |
1498 |
-</p> |
1499 |
+<ul> |
1500 |
+ <li> |
1501 |
+ <uri link="http://samwel.tk/laptop_mode/">Laptop Mode Tools Homepage</uri>, |
1502 |
+ includes <uri link="http://samwel.tk/laptop_mode/laptop_mode">About laptop |
1503 |
+ mode</uri>. |
1504 |
+ </li> |
1505 |
+ <li> |
1506 |
+ <uri link="http://www.lesswatts.org/projects/powertop/">PowerTOP</uri>, an |
1507 |
+ interactive application helping users to find out which processes are |
1508 |
+ forcing wakeups on the CPU most often. |
1509 |
+ </li> |
1510 |
+</ul> |
1511 |
|
1512 |
</body> |
1513 |
</section> |
1514 |
<section> |
1515 |
-<title>Limiting Write Accesses</title> |
1516 |
+<title>Articles and Guides</title> |
1517 |
<body> |
1518 |
|
1519 |
-<p> |
1520 |
-If you don't want to use laptop-mode, you must take special care to disable |
1521 |
-services that write to your disk frequently - <c>syslogd</c> is a good |
1522 |
-candidate, for example. You probably don't want to shut it down completely, but |
1523 |
-it's possible to modify the config file so that "unnecessary" things don't get |
1524 |
-logged and thus don't create disk traffic. <c>Cups</c> writes to disk |
1525 |
-periodically, so consider shutting it down and only enable it manually when |
1526 |
-needed. |
1527 |
-</p> |
1528 |
- |
1529 |
-<pre caption="Disabling cups in battery mode"> |
1530 |
-# <i>rc-update del cupsd battery</i> |
1531 |
-</pre> |
1532 |
- |
1533 |
-<p> |
1534 |
-You can also use <c>lm-profiler</c> from laptop-mode-tools (see above) to find |
1535 |
-services to disable. Once you eliminated all of them, go on with configuring |
1536 |
-hdparm. |
1537 |
-</p> |
1538 |
- |
1539 |
-</body> |
1540 |
-</section> |
1541 |
-<section> |
1542 |
-<title>hdparm</title> |
1543 |
-<body> |
1544 |
- |
1545 |
-<p> |
1546 |
-The second possibility is using <c>hdparm</c>. Skip this if |
1547 |
-you are using laptop-mode. Otherwise, edit <path>/etc/conf.d/hdparm</path> and |
1548 |
-add the following values to your drive entries. This example assumes your hard |
1549 |
-drive is called <b>hda</b>: |
1550 |
-</p> |
1551 |
- |
1552 |
-<pre caption="Using /etc/conf.d/hdparm for disk standby"> |
1553 |
-hda_args="-q -S12" |
1554 |
-</pre> |
1555 |
- |
1556 |
-<p> |
1557 |
-This will activate power management for your hard drive. If you ever want to |
1558 |
-deactivate power management, you can edit <path>/etc/conf.d/hdparm</path> and |
1559 |
-change the values to <c>-q -S0</c>, or just run <c>hdparm -q -S0 /dev/hda</c>. |
1560 |
-</p> |
1561 |
- |
1562 |
-<p> |
1563 |
-See <c>man hdparm</c> for the options. Though you can always start <c>hdparm</c> |
1564 |
-manually when you are on battery power by running <c>/etc/init.d/hdparm |
1565 |
-start</c>, it's much easier to automate its startup and shutdown. To do so, add |
1566 |
-<c>hdparm</c> to the battery runlevel so that it will automatically enable power |
1567 |
-management. |
1568 |
-</p> |
1569 |
- |
1570 |
-<pre caption="Automate disk standby settings"> |
1571 |
-# <i>rc-update add hdparm battery</i> |
1572 |
-</pre> |
1573 |
- |
1574 |
-<impo> |
1575 |
-Be careful with sleep/spin down settings of your hard drive. Setting it to |
1576 |
-small values might wear out your drive and lose warranty. |
1577 |
-</impo> |
1578 |
- |
1579 |
-</body> |
1580 |
-</section> |
1581 |
-<section> |
1582 |
-<title>Other tricks</title> |
1583 |
-<body> |
1584 |
- |
1585 |
-<p> |
1586 |
-Another possibility is to deactivate swap in battery mode. Before writing a |
1587 |
-swapon/swapoff switcher, make sure there is enough RAM and swap isn't used |
1588 |
-heavily, otherwise you'll be in big problems. |
1589 |
-</p> |
1590 |
- |
1591 |
-<p> |
1592 |
-If you don't want to use laptop-mode, it's still possible to minimize disk |
1593 |
-access by mounting certain directories as <c>tmpfs</c> - write accesses are not |
1594 |
-stored on a disk, but in main memory and get lost with unmounting. Often it's |
1595 |
-useful to mount <path>/tmp</path> like this - you don't have to pay special |
1596 |
-attention as it gets cleared on every reboot regardless whether it was mounted |
1597 |
-on disk or in RAM. Just make sure you have enough RAM and no program (like a |
1598 |
-download client or compress utility) needs extraordinary much space in |
1599 |
-<path>/tmp</path>. To activate this, enable tmpfs support in your kernel and |
1600 |
-add a line to <path>/etc/fstab</path> like this: |
1601 |
-</p> |
1602 |
- |
1603 |
-<pre caption="Editing /etc/fstab to make /tmp even more volatile"> |
1604 |
-none /tmp tmpfs size=32m 0 0 |
1605 |
-</pre> |
1606 |
- |
1607 |
-<warn> |
1608 |
-Pay attention to the size parameter and modify it for your system. If you're |
1609 |
-unsure, don't try this at all, it can become a performance bottleneck easily. In |
1610 |
-case you want to mount <path>/var/log</path> like this, make sure to merge the |
1611 |
-log files to disk before unmounting. They are essential. Don't attempt to mount |
1612 |
-<path>/var/tmp</path> like this. Portage uses it for compiling... |
1613 |
-</warn> |
1614 |
- |
1615 |
-</body> |
1616 |
-</section> |
1617 |
-</chapter> |
1618 |
- |
1619 |
-<chapter> |
1620 |
-<title>Power Management For Other Devices</title> |
1621 |
-<section> |
1622 |
-<title>Graphics Cards</title> |
1623 |
-<body> |
1624 |
- |
1625 |
-<p> |
1626 |
-In case you own an ATI graphics card supporting PowerPlay (dynamic clock |
1627 |
-scaling for the graphics processing unit GPU), you can activate this |
1628 |
-feature in X.org. Open <path>/etc/X11/xorg.conf</path> and add (or enable) the |
1629 |
-<c>DynamicClocks</c> option in the Device section. Please notice that this |
1630 |
-feature will lead to crashes on some systems. |
1631 |
-</p> |
1632 |
- |
1633 |
-<pre caption="Enabling ATI PowerPlay support in X.org"> |
1634 |
-Section "Device" |
1635 |
-[...] |
1636 |
-Option "DynamicClocks" "on" |
1637 |
-EndSection |
1638 |
-</pre> |
1639 |
- |
1640 |
-</body> |
1641 |
-</section> |
1642 |
-<section> |
1643 |
-<title>Wireless Power Management</title> |
1644 |
-<body> |
1645 |
- |
1646 |
-<p> |
1647 |
-Wireless LAN cards consume quite a bit of energy. Put them in Power Management |
1648 |
-mode just like your hard drives. |
1649 |
-</p> |
1650 |
- |
1651 |
-<note> |
1652 |
-This script assumes your wireless interface is called <c>wlan0</c>; replace |
1653 |
-this with the actual name of your interface. |
1654 |
-</note> |
1655 |
- |
1656 |
-<p> |
1657 |
-Add the following option to <path>/etc/conf.d/net</path> to automatically enable |
1658 |
-power management for your wireless card: |
1659 |
-</p> |
1660 |
- |
1661 |
-<pre caption="Automated WLAN Power Management"> |
1662 |
-iwconfig_wlan0="power on" |
1663 |
-</pre> |
1664 |
- |
1665 |
-<p> |
1666 |
-See <c>man iwconfig</c> for details and more options like the period between |
1667 |
-wakeups or timeout settings. If your driver and access point support changing |
1668 |
-the beacon time, this is a good starting point to save even more energy. |
1669 |
-</p> |
1670 |
- |
1671 |
-</body> |
1672 |
-</section> |
1673 |
-<section> |
1674 |
-<title>USB Power Management</title> |
1675 |
-<body> |
1676 |
- |
1677 |
-<p> |
1678 |
-There are two problems with USB devices regarding energy consumption: First, |
1679 |
-devices like USB mice, digital cameras or USB sticks consume energy while |
1680 |
-plugged in. You cannot avoid this (nevertheless remove them in case they're not |
1681 |
-needed). Second, when there are USB devices plugged in, the USB host controller |
1682 |
-periodically accesses the bus which in turn prevents the CPU from going into |
1683 |
-sleep mode. The kernel offers an experimental option to enable suspension of |
1684 |
-USB devices through driver calls or one of the <path>power/state</path> files |
1685 |
-in <path>/sys</path>. |
1686 |
-</p> |
1687 |
- |
1688 |
-<pre caption="Enabling USB suspend support in the kernel"> |
1689 |
-Device Drivers |
1690 |
- USB support |
1691 |
- [*] Support for Host-side USB |
1692 |
- [*] USB suspend/resume (EXPERIMENTAL) |
1693 |
-</pre> |
1694 |
- |
1695 |
-</body> |
1696 |
-</section> |
1697 |
-</chapter> |
1698 |
- |
1699 |
-<chapter> |
1700 |
-<title>Sleep States: sleep, standby, and suspend to disk</title> |
1701 |
-<section> |
1702 |
-<body> |
1703 |
- |
1704 |
-<p> |
1705 |
-ACPI defines different sleep states. The more important ones are |
1706 |
-</p> |
1707 |
- |
1708 |
<ul> |
1709 |
- <li>S1 aka Standby</li> |
1710 |
- <li>S3 aka Suspend to RAM aka Sleep</li> |
1711 |
- <li>S4 aka Suspend to Disk aka Hibernate</li> |
1712 |
+ <li> |
1713 |
+ A ThinkWiki article on <uri |
1714 |
+ link="http://www.thinkwiki.org/wiki/How_to_reduce_power_consumption">How to |
1715 |
+ reduce power consumption</uri> (on Linux). This article offers an exhaustive |
1716 |
+ list of measures one can take. However, it should be noted that the laptop |
1717 |
+ mode tools implements the majority of these (if properly configured). |
1718 |
+ </li> |
1719 |
</ul> |
1720 |
|
1721 |
-<p> |
1722 |
-They can be called whenever the system is not in use, but a shutdown is not |
1723 |
-wanted due to the long boot time. |
1724 |
-</p> |
1725 |
- |
1726 |
-</body> |
1727 |
-</section> |
1728 |
-<section> |
1729 |
-<title>Sleep (S3)</title> |
1730 |
-<body> |
1731 |
- |
1732 |
-<p> |
1733 |
-The ACPI support for these sleep states is marked experimental for good reason. |
1734 |
-APM sleep states seem to be more stable, however you can't use APM and ACPI |
1735 |
-together. |
1736 |
-</p> |
1737 |
- |
1738 |
-<pre caption="Kernel configuration for the various suspend types"> |
1739 |
- Power Management Options ---> |
1740 |
- [*] Power Management support |
1741 |
- [*] Suspend to RAM and standby |
1742 |
-</pre> |
1743 |
- |
1744 |
-<p> |
1745 |
-Once your kernel is properly configured, you can use the |
1746 |
-<c>hibernate-script</c> to activate suspend or sleep mode. Let's install that |
1747 |
-first. |
1748 |
-</p> |
1749 |
- |
1750 |
-<pre caption="Installing the hibernate-script"> |
1751 |
-# <i>emerge hibernate-script</i> |
1752 |
-</pre> |
1753 |
- |
1754 |
-<p> |
1755 |
-Some configuration has to be done in <path>/etc/hibernate</path>. The default |
1756 |
-package introduces a few configuration files for each sleep state. Options that |
1757 |
-are common to all suspend methods are placed in <path>common.conf</path>; make |
1758 |
-sure this file is properly set up for your system. |
1759 |
-</p> |
1760 |
- |
1761 |
-<p> |
1762 |
-To configure sleep, edit <path>sysfs-ram.conf</path> in |
1763 |
-<path>/etc/hibernate</path>. <c>UseSysfsPowerState mem</c> is already setup |
1764 |
-correctly, but if you need to make further changes to this particular sleep |
1765 |
-state (or any other sleep state) you should add them to |
1766 |
-<path>/etc/hibernate/hibernate.conf</path>. The comments and option names will |
1767 |
-guide you. If you use nfs or samba shares over the network, make sure to |
1768 |
-shutdown the appropriate init scripts to avoid timeouts. |
1769 |
-</p> |
1770 |
- |
1771 |
-<note> |
1772 |
-For more information on setting up sleep states, read <c>man |
1773 |
-hibernate.conf</c>. |
1774 |
-</note> |
1775 |
- |
1776 |
-<p> |
1777 |
-Ready? Now is the last chance to backup any data you want to keep after |
1778 |
-executing the next command. Notice that you probably have to hit a special key |
1779 |
-like <c>Fn</c> to resume from sleep. |
1780 |
-</p> |
1781 |
- |
1782 |
-<pre caption="Calling sleep"> |
1783 |
-# <i>hibernate-ram</i> |
1784 |
-</pre> |
1785 |
- |
1786 |
-<p> |
1787 |
-If you're still reading, it seems to work. You can also setup standby (S1) in a |
1788 |
-similar way by editing <path>sysfs-ram.conf</path> and changing |
1789 |
-"UseSysfsPowerState mem" to "UseSysfsPowerState standby". S3 and S4 are the more |
1790 |
-interesting sleep states due to greater energy savings however. |
1791 |
-</p> |
1792 |
- |
1793 |
-</body> |
1794 |
-</section> |
1795 |
-<section> |
1796 |
-<title>Hibernate (S4)</title> |
1797 |
-<body> |
1798 |
- |
1799 |
-<p> |
1800 |
-This section introduces hibernation, where a snapshot of the running system is |
1801 |
-written to disk before powering off. On resume, the snapshot is loaded and you |
1802 |
-can go on working at exactly the point you called hibernate before. |
1803 |
-</p> |
1804 |
- |
1805 |
-<warn> |
1806 |
-Don't exchange non hot-pluggable hardware when suspended. Don't attempt to load |
1807 |
-a snapshot with a different kernel image than the one it was created with. |
1808 |
-Shutdown any NFS or samba server/client before hibernating. |
1809 |
-</warn> |
1810 |
- |
1811 |
-<p> |
1812 |
-There are two different implementations for S4. The original one is swsusp, |
1813 |
-then there is the newer tuxonice (formerly suspend2) with a nicer interface |
1814 |
-(including fbsplash support). A <uri |
1815 |
-link="http://tuxonice.net/features.html#compare">feature comparison</uri> is |
1816 |
-available at the <uri link="http://www.tuxonice.net">tuxonice homepage</uri>. |
1817 |
-There used to be Suspend-to-Disk (pmdisk), a fork of swsusp, but it has been |
1818 |
-merged back. |
1819 |
-</p> |
1820 |
- |
1821 |
-<p> |
1822 |
-TuxOnIce is not included in the mainline kernel yet, therefore you either have |
1823 |
-to patch your kernel sources with the patches provided by <uri |
1824 |
-link="http://www.tuxonice.net">tuxonice.net</uri> or use |
1825 |
-<c>sys-kernel/tuxonice-sources</c>. |
1826 |
-</p> |
1827 |
- |
1828 |
-<p> |
1829 |
-The kernel part for both swusp and TuxOnIce is as follows: |
1830 |
-</p> |
1831 |
- |
1832 |
-<pre caption="Kernel configuration for the various suspend types"> |
1833 |
-Power Management support ---> |
1834 |
- <comment>(hibernate with swsusp)</comment> |
1835 |
- [*] Hibernation (aka 'suspend to disk') |
1836 |
- <comment>(replace /dev/SWAP with your swap partition)</comment> |
1837 |
- (/dev/SWAP) Default resume partition |
1838 |
- |
1839 |
- <comment>(hibernate with TuxOnIce)</comment> |
1840 |
- Enhanced Hibernation (TuxOnIce) |
1841 |
- --- Image Storage (you need at least one allocator) |
1842 |
- [*] File Allocator |
1843 |
- [*] Swap Allocator |
1844 |
- --- General Options |
1845 |
- [*] Compression support |
1846 |
- [ ] Allow Keep Image Mode |
1847 |
- [*] Replace swsusp by default |
1848 |
-</pre> |
1849 |
- |
1850 |
-<p> |
1851 |
-The configuration for swsusp is rather easy. If you didn't store the location |
1852 |
-of your swap partition in the kernel config, you can also pass it as a |
1853 |
-parameter with the <c>resume=/dev/SWAP</c> directive. If booting is not |
1854 |
-possible due to a broken image, use the <c>noresume</c> kernel parameter. The |
1855 |
-<c>hibernate-cleanup</c> init script invalidates swsusp images during the boot |
1856 |
-process. |
1857 |
-</p> |
1858 |
- |
1859 |
-<pre caption="Invalidating swsusp images during the boot process"> |
1860 |
-# <i>rc-update add hibernate-cleanup boot</i> |
1861 |
-</pre> |
1862 |
- |
1863 |
-<p> |
1864 |
-To activate hibernate with swsusp, use the hibernate script and set |
1865 |
-<c>UseSysfsPowerState disk</c> in <path>/etc/hibernate/sysfs-disk</path>. |
1866 |
-</p> |
1867 |
- |
1868 |
-<warn> |
1869 |
-Backup your data before doing this. Run <c>sync</c> before executing one of the |
1870 |
-commands to have cached data written to disk. First try it outside of X, then |
1871 |
-with X running, but not logged in. |
1872 |
-</warn> |
1873 |
- |
1874 |
-<p> |
1875 |
-If you experience kernel panics due to uhci or similar, try to compile USB |
1876 |
-support as module and unload the modules before sending your laptop to sleep |
1877 |
-mode. There are configuration options for this in <path>common.conf</path> |
1878 |
-</p> |
1879 |
- |
1880 |
-<pre caption="Hibernating with swsusp"> |
1881 |
-# <i>nano -w /etc/hibernate/common.conf</i> |
1882 |
-<comment>(Make sure you have a backup of your data)</comment> |
1883 |
-# <i>hibernate</i> |
1884 |
-</pre> |
1885 |
- |
1886 |
-<p> |
1887 |
-The following section discusses the setup of TuxOnIce including fbsplash support |
1888 |
-for a nice graphical progress bar during suspend and resume. |
1889 |
-</p> |
1890 |
- |
1891 |
-<p> |
1892 |
-The first part of the configuration is similar to the configuration of swsusp. |
1893 |
-In case you didn't store the location of your swap partition in the kernel |
1894 |
-config, you have to pass it as a kernel parameter with the |
1895 |
-<c>resume=swap:/dev/SWAP</c> directive. If booting is not possible due to a |
1896 |
-broken image, append the <c>noresume</c> parameter. Additionally, the |
1897 |
-<c>hibernate-cleanup</c> init script invalidates TuxOnIce images during the boot |
1898 |
-process. |
1899 |
-</p> |
1900 |
- |
1901 |
-<pre caption="Invalidating TuxOnIce images during the boot process"> |
1902 |
-# <i>rc-update add hibernate-cleanup boot</i> |
1903 |
-</pre> |
1904 |
- |
1905 |
-<p> |
1906 |
-Now edit <path>/etc/hibernate/tuxonice.conf</path>, enable the <c>TuxOnIce</c> |
1907 |
-options you need. Do not enable the <c>fbsplash</c> options in |
1908 |
-<c>common.conf</c> just yet. |
1909 |
-</p> |
1910 |
- |
1911 |
-<pre caption="Hibernating with TuxOnIce"> |
1912 |
-# <i>nano -w /etc/hibernate/tuxonice.conf</i> |
1913 |
-<comment>(Make sure you have a backup of your data)</comment> |
1914 |
-# <i>hibernate</i> |
1915 |
-</pre> |
1916 |
- |
1917 |
-<p> |
1918 |
-Please configure <c>fbsplash</c> now if you didn't do already. To enable |
1919 |
-fbsplash support during hibernation, the <c>sys-apps/tuxonice-userui</c> package |
1920 |
-is needed. Additionally, you've got to enable the <c>fbsplash</c> USE flag. |
1921 |
-</p> |
1922 |
- |
1923 |
-<pre caption="Installing tuxonice-userui"> |
1924 |
-# <i>echo "sys-apps/tuxonice-userui fbsplash" >> /etc/portage/package.use</i> |
1925 |
-# <i>emerge tuxonice-userui</i> |
1926 |
-</pre> |
1927 |
- |
1928 |
-<p> |
1929 |
-The ebuild tells you to make a symlink to the theme you want to use. For |
1930 |
-example, to use the <c>livecd-2005.1</c> theme, run the following command: |
1931 |
-</p> |
1932 |
- |
1933 |
-<pre caption="Using the livecd-2005.1 theme during hibernation"> |
1934 |
-# <i>ln -sfn /etc/splash/livecd-2005.1 /etc/splash/tuxonice</i> |
1935 |
-</pre> |
1936 |
- |
1937 |
-<p> |
1938 |
-If you don't want a black screen in the first part of the resume process, you |
1939 |
-have to add the <c>tuxoniceui_fbsplash</c> tool to your initrd image. Assuming |
1940 |
-you created the initrd image with <c>splash_geninitramfs</c> and saved it as |
1941 |
-<path>/boot/fbsplash-emergence-1024x768</path>, here's how to do that. |
1942 |
-</p> |
1943 |
- |
1944 |
-<pre caption="Adding tuxoniceui_fbsplash to an initrd image"> |
1945 |
-# <i>mount /boot</i> |
1946 |
-# <i>mkdir ~/initrd.d</i> |
1947 |
-# <i>cp /boot/fbsplash-emergence-1024x768 ~/initrd.d/</i> |
1948 |
-# <i>cd ~/initrd.d</i> |
1949 |
-# <i>gunzip -c fbsplash-emergence-1024x768 | cpio -idm --quiet -H newc</i> |
1950 |
-# <i>rm fbsplash-emergence-1024x768</i> |
1951 |
-# <i>cp /usr/sbin/tuxoniceui_fbsplash sbin/</i> |
1952 |
-# <i>find . | cpio --quiet --dereference -o -H newc | gzip -9 > /boot/fbsplash-tuxonice-emergence-1024x768</i> |
1953 |
-</pre> |
1954 |
- |
1955 |
-<p> |
1956 |
-Afterwards adjust <path>grub.conf</path> (or <path>lilo.conf</path>) so that |
1957 |
-your TuxOnIce kernel uses |
1958 |
-<path>/boot/fbsplash-tuxonice-emergence-1024x768</path> as initrd image. You can |
1959 |
-now test a dry run to see if everything is setup correctly. |
1960 |
-</p> |
1961 |
- |
1962 |
-<pre caption="Test run for fbsplash hibernation"> |
1963 |
-# <i>tuxoniceui_fbsplash -t</i> |
1964 |
-</pre> |
1965 |
- |
1966 |
-<p> |
1967 |
-Afterwards open <path>/etc/hibernate/common.conf</path> and activate the |
1968 |
-fbsplash options. Execute <c>hibernate</c> and enjoy. |
1969 |
-</p> |
1970 |
- |
1971 |
-</body> |
1972 |
-</section> |
1973 |
-</chapter> |
1974 |
- |
1975 |
-<chapter> |
1976 |
-<title>Troubleshooting</title> |
1977 |
-<section> |
1978 |
-<body> |
1979 |
- |
1980 |
-<p> |
1981 |
-<e>Q:</e> I'm trying to change the CPU frequency, but |
1982 |
-<path>/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor</path> does not |
1983 |
-exist. |
1984 |
-</p> |
1985 |
- |
1986 |
-<p> |
1987 |
-<e>A:</e> Make sure your processor supports CPU frequency scaling and you chose |
1988 |
-the right CPUFreq driver for your processor. Here is a list of processors that |
1989 |
-are supported by cpufreq (kernel 2.6.7): ARM Integrator, ARM-SA1100, ARM-SA1110, |
1990 |
-AMD Elan - SC400, SC410, AMD mobile K6-2+, AMD mobile K6-3+, AMD mobile Duron, |
1991 |
-AMD mobile Athlon, AMD Opteron, AMD Athlon 64, Cyrix Media GXm, Intel mobile |
1992 |
-PIII and Intel mobile PIII-M on certain chipsets, Intel Pentium 4, Intel Xeon, |
1993 |
-Intel Pentium M (Centrino), National Semiconductors Geode GX, Transmeta Crusoe, |
1994 |
-VIA Cyrix 3 / C3, UltraSPARC-III, SuperH SH-3, SH-4, several "PowerBook" and |
1995 |
-"iBook2" and various processors on some ACPI 2.0-compatible systems (only if |
1996 |
-"ACPI Processor Performance States" are available to the ACPI/BIOS interface). |
1997 |
-</p> |
1998 |
- |
1999 |
-<p> |
2000 |
-<e>Q:</e> My laptop supports frequency scaling, but |
2001 |
-<path>/sys/devices/system/cpu/cpu0/cpufreq/</path> is empty. |
2002 |
-</p> |
2003 |
- |
2004 |
-<p> |
2005 |
-<e>A:</e> Look for ACPI related error messages with <c>dmesg | grep ACPI</c>. |
2006 |
-Try to update the BIOS, especially if a broken DSDT is reported. You can also |
2007 |
-try to fix it yourself (which is beyond the scope of this guide). |
2008 |
-</p> |
2009 |
- |
2010 |
-<p> |
2011 |
-<e>Q:</e> My laptop supports frequency scaling, but according to |
2012 |
-<path>/proc/cpuinfo</path> the speed never changes. |
2013 |
-</p> |
2014 |
- |
2015 |
-<p> |
2016 |
-<e>A:</e> Probably you have activated symmetric multiprocessing support |
2017 |
-(CONFIG_SMP) in your kernel. Deactivate it and it should work. Some older |
2018 |
-kernels had a bug causing this. In that case, run <c>emerge x86info</c>, update |
2019 |
-your kernel as asked and check the current frequency with <c>x86info -mhz</c>. |
2020 |
-</p> |
2021 |
- |
2022 |
-<p> |
2023 |
-<e>Q:</e> I can change the CPU frequency, but the range is not as wide as in |
2024 |
-another OS. |
2025 |
-</p> |
2026 |
- |
2027 |
-<p> |
2028 |
-<e>A:</e> You can combine frequency scaling with ACPI throttling to get a lower |
2029 |
-minimum frequency. Notice that throttling doesn't save much energy and is mainly |
2030 |
-used for thermal management (keeping your laptop cool and quiet). You can read |
2031 |
-the current throttling state with <c>cat /proc/acpi/processor/CPU/throttling</c> |
2032 |
-and change it with <c>echo -n "0:x" > /proc/acpi/processor/CPU/limit</c>, where |
2033 |
-x is one of the Tx states listed in |
2034 |
-<path>/proc/acpi/processor/CPU/throttling</path>. |
2035 |
-</p> |
2036 |
- |
2037 |
-<p> |
2038 |
-<e>Q:</e> When configuring the kernel, powersave, performance and userspace |
2039 |
-governors show up, but that ondemand thing is missing. Where do I get it? |
2040 |
-</p> |
2041 |
- |
2042 |
-<p> |
2043 |
-<e>A:</e> The ondemand governor is only included in recent kernel sources. Try |
2044 |
-updating them. |
2045 |
-</p> |
2046 |
- |
2047 |
-<p> |
2048 |
-<e>Q:</e> Battery life time seems to be worse than before. |
2049 |
-</p> |
2050 |
- |
2051 |
-<p> |
2052 |
-<e>A:</e> Check your BIOS settings. Maybe you forgot to re-enable some of the |
2053 |
-settings. |
2054 |
-</p> |
2055 |
- |
2056 |
-<p> |
2057 |
-<e>Q:</e> My battery is charged, but KDE reports there would be 0% left and |
2058 |
-immediately shuts down. |
2059 |
-</p> |
2060 |
- |
2061 |
-<p> |
2062 |
-<e>A:</e> Check that battery support is compiled into your kernel. If you use |
2063 |
-it as a module, make sure the module is loaded. |
2064 |
-</p> |
2065 |
- |
2066 |
-<p> |
2067 |
-<e>Q:</e> My system logger reports things like "logger: ACPI group battery / |
2068 |
-action battery is not defined". |
2069 |
-</p> |
2070 |
- |
2071 |
-<p> |
2072 |
-<e>A:</e> This message is generated by the <path>/etc/acpi/default.sh</path> |
2073 |
-script that is shipped with acpid. You can safely ignore it. If you like to get |
2074 |
-rid of it, you can comment the appropriate line in |
2075 |
-<path>/etc/acpi/default.sh</path> as shown below: |
2076 |
-</p> |
2077 |
- |
2078 |
-<pre caption="Disabling warnings about unknown acpi events"> |
2079 |
- *) # logger "ACPI action $action is not defined" |
2080 |
-</pre> |
2081 |
- |
2082 |
-<p> |
2083 |
-<e>Q:</e> I have a Dell Inspiron 51XX and I don't get any ACPI events. |
2084 |
-</p> |
2085 |
- |
2086 |
-<p> |
2087 |
-<e>A:</e> This seems to be a kernel bug. Read on <uri |
2088 |
-link="http://bugme.osdl.org/show_bug.cgi?id=1752">here</uri>. |
2089 |
-</p> |
2090 |
- |
2091 |
-<p> |
2092 |
-<e>Q:</e> I activated the <c>DynamicClocks</c> option in <path>xorg.conf</path> |
2093 |
-and now X.org crashes / the screen stays black / my laptop doesn't shutdown |
2094 |
-properly. |
2095 |
-</p> |
2096 |
- |
2097 |
-<p> |
2098 |
-<e>A:</e> This happens on some systems. You have to disable |
2099 |
-<c>DynamicClocks</c>. |
2100 |
-</p> |
2101 |
- |
2102 |
-<p> |
2103 |
-<e>Q:</e> I want to use TuxOnIce, but it tells me my swap partition is too |
2104 |
-small. Resizing is not an option. |
2105 |
-</p> |
2106 |
- |
2107 |
-<p> |
2108 |
-<e>A:</e> If there is enough free space on your system, you can use the |
2109 |
-filewriter instead of the swapwriter. The <c>hibernate-script</c> supports it as |
2110 |
-well. More information can be found in |
2111 |
-<path>/usr/src/linux/Documentation/power/tuxonice.txt</path>. |
2112 |
-</p> |
2113 |
- |
2114 |
-<p> |
2115 |
-<e>Q:</e> I just bought a brand new battery, but it only lasts for some |
2116 |
-minutes! What am I doing wrong? |
2117 |
-</p> |
2118 |
- |
2119 |
-<p> |
2120 |
-<e>A:</e> First follow your manufacturer's advice on how to charge the battery |
2121 |
-correctly. |
2122 |
-</p> |
2123 |
- |
2124 |
-<p> |
2125 |
-<e>Q:</e> The above didn't help. What should I do then? |
2126 |
-</p> |
2127 |
- |
2128 |
-<p> |
2129 |
-<e>A:</e> Some batteries sold as "new" are in fact old ones. Try the following: |
2130 |
-</p> |
2131 |
- |
2132 |
-<pre caption="Querying battery state"> |
2133 |
-$ <i>grep capacity /proc/acpi/battery/BAT0/info</i> |
2134 |
-design capacity: 47520 mWh |
2135 |
-last full capacity: 41830 mWh |
2136 |
-</pre> |
2137 |
- |
2138 |
-<p> |
2139 |
-If the "last full capacity" differs significantly from the design capacity, |
2140 |
-your battery is probably broken. Try to claim your warranty. |
2141 |
-</p> |
2142 |
- |
2143 |
-<p> |
2144 |
-<e>Q:</e> My problem is not listed above. Where should I go next? |
2145 |
-</p> |
2146 |
- |
2147 |
-<p> |
2148 |
-<e>A:</e> Don't fear to contact me, <mail link="earthwings@g.o">Dennis |
2149 |
-Nienhüser</mail>, directly. The <uri link="http://forums.gentoo.org">Gentoo |
2150 |
-Forums</uri> are a good place to get help as well. If you prefer IRC, try the |
2151 |
-<c>#gentoo-laptop</c> <uri link="irc://irc.gentoo.org">channel</uri>. |
2152 |
-</p> |
2153 |
- |
2154 |
</body> |
2155 |
</section> |
2156 |
</chapter> |