Kernel Bug Means Linux Power Usage Remains High

An anonymous reader writes "The significant Linux kernel power regression reported back in April, which ended up being attributed to PCI-E Active State Power Management, is still not resolved even as Ubuntu 11.10 and Fedora 16 approach. Until Linux is able to handle ASPM in a manner more like Windows or the device drivers explicitly set the ASPM flag, users of many modern laptops need to use the "pcie_aspm=force" option to regain much of their battery life. At least a power bug affecting newer Intel hardware with the "energy performance bias" feature has been fixed. There's more information in this LaunchPad bug report and in the latest power consumption testing."

Comments

Re:You mean Moronix, right?

[CajunArson]

Phoronix has issues because the guy running it likes to oversensationalize and hyperbolize to get traffic and ad revenue... which is to say it's exactly like Slashdot with the difference being that Phoronix actually does some useful work and there are valuable facts that Phoronix discovers.

The (multiple) kernel power bugs are a very real problem affecting a large number of Linux users and Phoronix helped to shine a light on the issue and at least get the word out about work-arounds. I don't hang on everything that Phoronix publishes, but dismissing it just shows that you want to remain wilfully ignorant about real issues surrounding Linux so that you can appear 'l33t' to your friends.

Finally!

[jaymzter]

Seems like its been so long since relevant technical submissions were made to /. I remember being able to learn so many interesting OS tricks from poster's comments to articles and hearing about new software.

Now it's mostly just crap about who pissed on who's patents...

Re:Finally!

[cadeon]

Unfortunately, that's what the majority of the news is these days.

Years ago, a kernel regression that didn't result in a lockup or massive data corruption would have been borderline slow-news-day material. Today, software quality as a whole has increased, and there's not as much of that (or as many groundbreaking new features) going on. There's still some interesting stuff going on in the mobile world, but PCs and Servers have largely been figured out for the time being. At least compared to what it was a while back.

As much as I'd like to jump on this "Blame slashdot, slashdot sucks now" bandwagon, they're just reporting what's happening, IMHO.

And if they aren't reporting what you think is newsworthy, blame yourself for not submitting 'real' stories and/or not drinking from the firehose.

Re:Finally!

[djlowe]

Now it's mostly just crap about who pissed on who's patents

Well, that's marginally better than the copyright wars that reigned here not so long ago... or the global warming debate... or... what was before that? I forget.

I imagine, however, that those generated more revenue. Patent battles among corporations are pretty much a battle among giants, and most of us here are just nerdly peons, fairly removed from such. They're gonna do whatever they want, work it out in the end, and the rest of us will get shat upon, one way or another.

From here in the "cheap seats"? Shit is shit, regardless of who is dumping it on you, or so it seems to me.

Cynically,

dj

It is not something that can be resolved...

[kvvbassboy]

It's a problem with the BIOS manufacturers, and the BIOS incorrectly reporting its ASPM capability. When an OEM installs Windows on a laptop, it can correctly tune these settings. But for a fresh install of Linux that YOU performed, a database of every motherboard + BIOS combination needs to be maintained in the open to set the force PCIE ASPM flag. If set wrongly, when the BIOS doesn't support it, it could lead to locking which is far more serious.

There are other solutions to effectively manage power in Linux, like Jupiter.

For more (and better) information, see the following links: About the Kernel 3.0 "Power Regression" Myth and PCIe, power management, and problematic BIOSes

Re:Intel?

[Anonymous Coward]

It's a motherboard issue. BIOS supports ASPM but doesn't advertise it => Linux doesn't try using hardware that isn't there => power usage goes up => Linux gets blamed. Fucking Microsoft.

Why bother?

[msobkow]

The marginal performance improvements you get by tweaking kernel settings will not make one whit of difference to the average user unless there is a glaring performance issue like the power drain currently being discussed.

Grandma isn't going to install Linux on her laptop -- you are. And as the technically knowledgeable person, you should be doing any such tweaking. Other systems have the benefit of the OEM doing the tweaking and tuning, but it does get done by somebody. Don't blame Linux for not doing something automagically that other systems don't do, either.

"...most linux development is primarily focused on servers..."

I don't believe that's true. While server tweaks get the press, there is a lot of effort put into the desktop experience as well. You're just far more likely to hear about kernel tweaks that are useful for desktop performance from the "real time systems" people.

Re:absolutely....buggy BIOS's are the problem

[hedwards]

It's pretty well established that the ACPI implementation that MS was using with Win XP was non-standard. The one that folks had access to wouldn't compile the DSDTs that were coming with a lot of the computers because they were buggy and non-standard. MS had the advantage of controlling the only validation program that mattered and could hard code into their OS the bits necessary to work with the most common bugs.

Unfortunately for Linux, *BSD and everybody else, those coders didn't have access to that information and had to go to a huge amount of work to rewrite the DSDT and load that so that it would work as the standard specify.

Also, nice ad hominem you've got there, I am not a Linux fanboy,