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Kernel Bug Means Linux Power Usage Remains High

Posted by timothy on from the wrong-kind-of-power-user dept.

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."

1 of 179 comments (clear)

  1. It is not something that can be resolved... by kvvbassboy · · Score: 5, Informative

    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