What’s eating the battery life of my Linux laptop? Which software component causes the most power to be consumed? These are important questions without a good answer… until now. Intel announced the PowerTOP tool, a program that collects the various pieces of information from your system and presents an overview of how well your laptop is doing in terms of power savings. A number of apps, like Firefox, Evolution and Gaim have been modified by Intel to help consume less power and hopefully these patches will be integrated to their main trees or by distros.
Isn’t it a bit ironic that the hall-of-shame list contains applications such as gnome-power-manager and S06cpuspeed – who’s purpose, as I understand, includes saving power?
Oh, and the ibm-acpi module – required by IBM laptops to check battery, control LCD brightness, etc. – is there, too.
Lets find solutions and not guiltys.
Step one is finding where to concentrate efforts, so identifying guilty apps/modules is not idle play. And yes, the OP is right, it’s highly ironic!
“Whose” is possessive, “who’s” is a contraction of “who is.”
“Whose” is possessive, “who’s” is a contraction of “who is.”
And that is a comma splice.
No, it’s not. It’s a sentence fragment consisting of a list of two things. If you’re going to flame off-topic-wise, do it right.
Not ironic. XOrg has a broken DPMS notification system which is being fixed. If we don’t poll X, then we currently don’t know if the machine is in DPMS sleep or not. When we get the new API, we can remove polling completely.
Richard Hughes (author of gnome-power-manager)
Intel has done some great work in the OSS realm. Great job, Intel!
well done intel well done. keep it up.
I really don’t understand how people can think that polling is ever the right solution. It’s one of the first things you learn when studying low-power circuitry: asynchronous circuits generally save power. The same thing applies to software. Asynchronous, event-based programming keeps the machine quiescent when nothing is happening.
I think this is one of the few penalties of the distributed method of software development. There is no core set of practices and ideas on how to solve problems that are produced by interactions up and down the entire stack. And the loose-coupling of components often means that the event one desires to wait for is not exposed by the interface for the underlying component.
> Why so much polling?
Because noone thought about the power usage when programming the application?
I bet that some parts of the code of a Linux distribution was written before laptops existed..
Sure, you’re right that highly distributed sw development like in free software leads to poor coherency, but the one nice thing about free software is that if you need an asynchronous notification not present in the original sw then you can add it, with proprietary sw you’re stuck having to find a workaround.
I think it is more likely that at the time some of this code has been written there hadn’t been any asynchronous method of doing the desired task.
For example take file change monitoring. If our operating system does not provide you a notification mechanism on file changes, you’re only option left is to do polling.
Or RSS feeds: news aggregators have to poll their URIs since they can’t just broadcast that they have new content available.
Even w/o the power consumption in mind, polling should be regarded as bad solution _always_, as it’s also CPU consuming. You always have a trade-of with polling, between lag and cost. You don’t win anything with polling.
go tell SUN with their Crossbow solution. They do revert to polling network-cards sometimes for a reason…..
But basically, yes, polling is not too good, but sometimes it seems to have it’s benefits and/or simply is needed to get at least going.
On the hardware side, you are often stuck with polling if the hardware in question does not support interrupts or other methods for the required operation. In those cases, you are stuck with it.
With the direct cooperation of a great manufacturer, I think Linux will be able to close quickly this “power” gap (usually about one hour of battery life) because it will give a tool to manage the settings of ram hungry software.
I do not know how far Intel will go also with BIOS settings and ACPI…but I do not complain, this move of course goes in the right way.
Everybody wins…(well, nearly everybody I mean 😉
As soon as it landed in the Debian repositories I gave it a spin. (yes, it’s there, in unstable, package powertop)
Too bad I have an iBook
I guess the thing works only on x86!
Could be that, or it could be that it needs a 2.6.21 kernel with CONFIG_TIMER_STATS enabled in the build. Does Debian have that too?
This is an interesting development. You don’t see many hardware giants pushing projects exclusively at Linux laptop users (both of us!).
Am I right in thinking the Intel platform has stolen a lot of ground in the high-performance server/mainframe area from Sun and other competitors in recent years? I wonder if this is the main reason we’ve seen them do so much lately for *nix compatibility with their hardware. Saving a few minutes of battery life on a laptop would I imagine translate to a pretty massive utility-bill saving for the owner of a Linux supercomputer with thousands of CPUs…
Whatever the reasons, I couldn’t be more pleased with Intel’s courting of the OSS community. My next computer will almost definitely have an Intel graphics card, and I’ll be keeping an eye on their wireless offerings as well.
http://www.urbandictionary.com/define.php?term=powertop
learn something new everyday >.>;
This is a great little tool. It suggested kernel options for me to configure for better power efficiency. The only issue I have is CONFIG_TIMER_STATS is not available in my kernel.
Can I get some votes too?
Well done Intel. With AMD and Intel working hard on the OSS side, perhaps we will see an end to driver compatibility hell? At the end of the day, more potential users = more potential sales!