The State of Linux Power Management 2006

In 2006, the importance of Power Management to Linux development is accelerating at an alarming rate. Hardware technology is evolving to become more intelligent -- and more common -- in many areas of computing. At the same time, the use of Linux continues to rapidly proliferate, especially in mobile and handheld devices, where power conservation is especially important the users and manufacturers. Linux Power Management support has typically been adequate for basic use, but has fallen short of the potential that exists in the hardware and in other software solutions. That doesn't have to be the case though, and several factors indicate that the tide is beginning to turn.

This paper describes the factors involved in this tidal flow and is divided into three parts:

Part 1: The Problems

Part 2: The Solutions

Part 3: The Progress

Part 1 takes a top-down approach to describe two major topics: what power management features users expect from hardware today (and what they want in the future), and what hardware technologies device and system manufacturers are implementing (now and in the future) to address these expectations.

Part 2 of this paper discusses the technical solutions to the problems described in Part 1. It is divided into three sections describing a) the User Interface, b) the System Libraries and Tools, and c) the Kernel Components.

Part 3 describes what the current state of the solutions described in Part 2 are, and reiterates the gaps between what we have today and what is desired. In many cases, these items are inhibited by a lack of support infrastructure. What these perceived needs are and what people and/or projects are addressing these is described. This section is based upon the discussions and conclusions of the 2006 Power Managemement Summit that was held in April 2006.