Linked by Eugenia Loli on Sun 13th May 2007 00:35 UTC, submitted by Luis
Intel 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.
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Why so much polling?
by PlatformAgnostic on Sun 13th May 2007 03:01 UTC
PlatformAgnostic
Member since:
2006-01-02

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.

Reply Score: 5

RE: Why so much polling?
by renox on Sun 13th May 2007 12:14 in reply to "Why so much polling?"
renox Member since:
2005-07-06

> 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.

Reply Parent Score: 3

RE[2]: Why so much polling?
by anda_skoa on Sun 13th May 2007 14:03 in reply to "RE: Why so much polling?"
anda_skoa Member since:
2005-07-07

Because noone thought about the power usage when programming the application?


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.

Reply Parent Score: 4

RE[2]: Why so much polling?
by Ford Prefect on Sun 13th May 2007 15:36 in reply to "RE: Why so much polling?"
Ford Prefect Member since:
2006-01-16

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.

Reply Parent Score: 4

RE: Why so much polling?
by agd5f on Mon 14th May 2007 18:07 in reply to "Why so much polling?"
agd5f Member since:
2007-04-05

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.

Reply Parent Score: 1