natty battery life issue identified

[wizard10000]

Swiped from /.

"For the Linux kernel power regressions that were found a few months ago, and hit in Ubuntu 11.04, Phoronix has found the regression that's still present in the Linux 3.0 kernel. The power regression is caused by a change in ASPM, the Active-State Power Management, for PCI Express support."

http://www.phoronix.com/scan.php?pag...638_aspm&num=1

[GreyGeek]

Re: natty battery life issue identified

That article also gives the workaround:

Given the thousands of users having this 2.6.38 power regression by this change, there is a big ASPM problem at hand. Fortunately, as PCI-E ASPM problems are not new, a few boot options can be used. Namely, most people affected by this issue will want to add "pcie_aspm=force" to their boot command line. Simply adding this will force Active-State Power Management to be enabled. This is supported before the Linux 2.6.38 kernel (looks to be going back to circa 2.6.27) and it is still supported today in the latest upstream Git. Just adding that to 2.6.38+ kernels on the systems I have tested will workaround this problem-causing commit and lead to noticeable power savings.

[Snowhog]

Re: natty battery life issue identified

Interesting. By 'mobile' I understand the author to mean laptop/notebook PCs, and not smart phones.

"This issue affects not everyone, but a significant number of people are if you go across various Linux forums, Ubuntu 11.04 reviews, the 270+ people in this Launchpad bug report, and in other online destinations."

I've added the kernel option to my /etc/default/grub file and updated grub 'to be on the safe side.'