Document ID: c03456595
Version: 1
Release Date: 2012-08-14
Last Updated: 2012-08-14
When Red Hat Enterprise Linux 6 is booted with Collaborative Power Control (CPC) disabled in the HP Power Regulator mode HP Dynamic, HP Static Low or HP Static High, in the ROM-Based Setup Utility (RBSU), the following warning message will be displayed in the Linux logs (dmesg or /var/log/message):
p4-clockmod: Warning: EST-capable CPU detected. The acpi-cpufreq module offers voltage scaling in addition of frequency scaling. You should use that instead of p4-clockmod, if
possible.The warning message indicates that the operating system will no longer be able to manage the P-states (processor frequency) on this server; this is expected.
CPC is a feature that allows the platform firmware and the operating system to coordinate processor performance. On HP ProLiant Gen8 servers the Collaborative Power Control is enabled by default.
Any HP ProLiant Gen8 server running Red Hat Enterprise Linux 6 with Collaborative Power Control (CPC) disabled in the RBSU.
The message shown above will not affect the operation or functionality of the server or Red Hat Enterprise Linux 6 and can be safely ignored.