Linux

Article Summary: This article provides information on Linux - "Package Power limit" and "Core power limit" notifications.
Environment:

    Linux - Various distributions - It seems to affect systems with kernel 2.6.18 and above.
    Intel based CPU

Issue:

    "Core power limit " and "Package power limit " notifications being continuously logged in the /var/log/messages.

Diagnostic Steps:

    /var/log/messages will show notifications similar to:
        Jun 21 09:34:55 compute-0-15 kernel: CPU7: Core power limit notification (total events = 1)
        Jun 21 09:34:55 compute-0-15 kernel: CPU21: Core power limit notification (total events = 1)
        Jun 21 09:34:55 compute-0-15 kernel: CPU25: Package power limit notification (total events = 1)
        Jun 21 09:34:55 compute-0-15 kernel: CPU3: Package power limit notification (total events = 1)

Resolution:

    This issue is currently still being worked by some software vendors.
    In the meantime, there are 2 possible workarounds:
        Clear PLN flag adding clearcpuid=229 to grub.conf or;
        Set the machine's Performance Profile to Max Performance in the BIOS, if that setting is available (Please, be aware that power consumption may increase if this option is chosen).


Note:

    Power Limit Notification is a feature that was added to the Sandy Bridge processors from Intel. The notification does not indicate a problem, and should not be reported as a Critical-level message.
    The occurrence of the power limit notification is routine, and the system should not be reporting the messages. They can be ignored.