CPU frequency management

To enable CPU frequency management, set LSF_MANAGE_FREQUENCY in lsf.conf. By default, CPU frequency management is not enabled (LSF_MANAGE_FREQUENCY=N). If LSF_MANAGE_FREQUENCY=N, CPU frequency management is disabled, and lim will not load elim.frequency.

System requirements

The following Linux kernel modules must be installed on all nodes:

  • msr
  • ibmaem
  • ipmi_si
  • acpi_cpufreq

All compute nodes have the cpufreq-util package installed.

Note: The linux kernel module may already be statically linked to the kernel. This can be confirmed in the file /boot/config-2.6.32-220.el6.x86_64 where "2.6.32-220" is the kernel number used.

When an OS is installed it may already contain the kernel module in the Linux kernel, so you cannot re-probe the module when the OS starts up. Check the following:

  • msr: CONFIG_X86_MSR
  • ibmaem: CONFIG_SENSORS_IBMAEM
  • ipmi_si: CONFIG_IPMI_SI
  • acpi_cpufreq: CONFIG_X86_ACPI_CPUFREQ

If the keyword equals "y", then the module is already statically linked. If there is an "m", it means you must perform a modprobe when the OS starts up.