Host CPU MHz Parameters Configuration¶
Some hosts support setting a maximum frequency for their CPU cores (application
cores and platform cores) and the support for this configuration can be verified
by looking at the
is_max_cpu_configurable capability with the system
host-show <host> command, that can assume two values:
configurable or not-configurable. You may need to configure a maximum scaled
frequency to avoid variability due to power and thermal issues when configured
for maximum performance. For these hosts, the following parameters control
the maximum frequency of their CPU cores:
cpu_max_freq_min_percentagedefines a system-wide minimum percentage of the maximum frequency allowed to be configured for CPUs. By default this parameter is set to 80, meaning that you can reduce the frequency only to a maximum of 80% of the
max_cpu_mhz_allowed. There is no need to apply the platform service parameters after changing it.
Run the Linux command sudo cpupower info on the host, to determine if the host has support for this configuration.
~(keystone_admin)] $ system service-parameter-modify platform config cpu_max_freq_min_percentage=<value-between-60-100>
This parameter can be set between 60% and 100%.
max_cpu_mhz_configuredto specify a maximum frequency for a particular host’s CPU cores.
~(keystone_admin)] $ system host-update <worker> max_cpu_mhz_configured=<frequency-in-MHz>
To restore a host’s CPU cores’
max_cpu_mhz_configuredvalue to it’s default value, the
max_cpu_mhz_allowedlabel can be passed to the host-update command.
~(keystone_admin)] $ system host-update <worker> max_cpu_mhz_configured=max_cpu_mhz_allowed
Configure Parameters using the GUI¶
The Host CPU MHz parameters configuration can also be made using the GUI.
In Host Inventory > Edit Host modal, there is a CPU Frequency Configuration dropbox field to configure the Max CPU Frequency of the host.
If CPU Frequency Configuration is set to Default, then the hosts’
max_cpu_mhz_allowed value is used as the Max CPU Frequency of the host.
If CPU Frequency Configuration is set to Custom, then a Max CPU Frequency (MHz)
field appears, allowing you to explicitly configure the Max CPU Frequency of the
host. Note that the configured value can NOT be less than the value allowed by
the service parameter