Linux Kernel Suffering Power Management Regression? 186
An anonymous reader writes "It appears that there's a big power management regression in the Linux kernel for the 2.6.38 and 2.6.39 development releases, including the kernel to ship with Ubuntu 11.04 next week. It's reportedly causing a 10~30% increase in power consumption on many laptop computers."
Re:Linus Torvalds and regression? (Score:5, Informative)
Well, what Linus is focused on is breaking user code - if it worked in a released kernel, you will not break it in any future kernel. I don't think there's any strict rule that performance must always be better or power consumption lower. Particularly if you're not doing something "right" and have to add additional checks/locks/synchronization for corner cases that can slow you down, they generally value correctness over performance. That's the case in many of Phoronix' sensationalist news, a development release is very fast but when you make it work 'right' the performance is no longer that impressive. That stuff will happen as close to the bleeding edge as most of the things they report on are. Of course, they do find real regressions too but it's easy to get the wrong impression...
Re:Only Power Users will notice (Score:4, Informative)
Linux on laptop (Score:3, Informative)
Why would anyone want to run linux on a laptop? Well, I run linux on my laptop. At first I had it set up to dual boot, but after months of not using the Windows partition I canned it and have never missed it. During the period I had both operating systems set up, I could compare them. Windows (Vista as installed at the factory) was dog slow and buggy (and before you poke fun at Vista, XP was just as bad on other laptops as received). Linux was snappy, remarkably stable, and supported the hardware very well with the exception of the oddball fingerprint reader which was a crappy idea anyway. It is a Lenovo X301 with SSD. If you stay away from Dell crap, 95% of laptops are pretty routine for linux. Even a lot of Dells are fine, but too many of them have oddball crap that is problematic.
I have successfully installed and run various linux distros on a Compaq/HP X1000, an HP2133 mini, a Samsung X460, and the Lenovo, as well as maybe a couple of dozen desktops, including pretty-much-black-box Shuttles and Aopen minis, as well as oddball home-builts, over the last 10 years or so. Things have gotten a lot better over the last several years in terms of video and wireless support. Hardware support is so good currently that it is far better than Windows, where you have to track down drivers for every piece of hardware on your own.
Having said that, my nephew has no trouble at all wiping the OEM Windows off of his laptops, one after the other, and installing his own fresh retail copies of Windows. He claims it performs much better without the bundled crap. I don't have the patience for that myself, and can't divine why anyone would WANT to run Windows, anyway.
I do think you miss the point when you claim that it is a waste of "resources" for linux to go to a lot of work to support a myriad of hardware. The resources you speak of are open source software engineers who are basically in it for the love of the challenge. Most of them are not interested in working on boring apps, anyway, and the non-hardware-related kernel proper has plenty of manpower working on it. The part of the kernel that is not hardware related doesn't even need a lot of manpower. Those are guys with vary special knowledge. The development resources available to linux are basically unlimited. Yes, the software engineers paid by corporations to work on linux make important contributions, including hardware support, but a lot of guys, particularly in hardware support, are independent geniuses on their own time. A lot of pieces of hardware owe their linux support to these individuals donating their time as a sideline because they relish the work, and individually are interested enough in some particular piece of hardware for their own use to figure it out.
Re:Only Power Users will notice (Score:4, Informative)
vista came on this laptop. there are NO xp drivers.
There are actually entire lines of computers that came with Vista but were too slow to actually run either it or Windows 7 properly, and at the same time are too new for anyone to have made XP drivers. Like half the computers sold with Vista before 2009 or so.
Never had any problems running Ubuntu on them though.