6b09bc3ae0
Change-Id: I2e2595aab1f80f5570b708c2d34b233387e5a963 Signed-off-by: Ngairangbam Mili <ngairangbam.mili@windriver.com>
76 lines
3.1 KiB
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76 lines
3.1 KiB
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.. _host-cpu-mhz-parameters-configuration-d9ccf907ede0:
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=====================================
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Host CPU MHz Parameters Configuration
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=====================================
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Some hosts support setting a maximum frequency for their CPU cores (application
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cores and platform cores) and the support for this configuration can be verified
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by looking at the ``is_max_cpu_configurable`` capability with the system
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:command:`host-show <host>` command, that can assume two values:
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**configurable** or **not-configurable**. You may need to configure a maximum scaled
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frequency to avoid variability due to power and thermal issues when configured
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for maximum performance. For these hosts, the following parameters control
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the maximum frequency of their CPU cores:
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- ``cpu_max_freq_min_percentage`` defines a system-wide minimum percentage of the maximum
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frequency allowed to be configured for CPUs. By default this parameter is set
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to 80, meaning that you can reduce the frequency only to a maximum of 80%
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of the ``max_cpu_mhz_allowed``. There is no need to apply the platform service
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parameters after changing it.
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.. Note::
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Run the Linux command :command:`sudo cpupower info` on the host, to
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determine if the host has support for this configuration.
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.. code-block:: none
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~(keystone_admin)] $ system service-parameter-modify platform config cpu_max_freq_min_percentage=<value-between-60-100>
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.. note::
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This parameter can be set between 60% and 100%.
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- Configure ``max_cpu_mhz_configured`` to specify a maximum frequency for a
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particular host's CPU cores.
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.. code-block:: none
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~(keystone_admin)] $ system host-update <worker> max_cpu_mhz_configured=<frequency-in-MHz>
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- To restore a host's CPU cores' ``max_cpu_mhz_configured`` value to it's
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default value, the ``max_cpu_mhz_allowed`` label can be passed to the
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:command:`host-update` command.
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.. code-block:: none
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~(keystone_admin)] $ system host-update <worker> max_cpu_mhz_configured=max_cpu_mhz_allowed
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----------------------------------
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Configure Parameters using the GUI
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----------------------------------
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The **Host CPU MHz** parameters configuration can also be made using the GUI.
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In **Host Inventory** > **Edit Host** modal, there is a **CPU Frequency Configuration**
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dropbox field to configure the Max CPU Frequency of the host.
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If **CPU Frequency Configuration** is set to **Default**, then the hosts'
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``max_cpu_mhz_allowed`` value is used as the Max CPU Frequency of the host.
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If **CPU Frequency Configuration** is set to **Custom**, then a **Max CPU Frequency (MHz)**
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field appears, allowing you to explicitly configure the Max CPU Frequency of the
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host. Note that the configured value can NOT be less than the value allowed by
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the service parameter ``cpu_max_freq_min_percentage``.
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.. figure:: figures/CPUFrequencyCustom.png
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:scale: 100%
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.. figure:: figures/CPUFrequencyDefault.png
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:scale: 100%
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.. only:: partner
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.. include:: /_includes/host-cpu-mhz-parameters-configuration.rest
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:start-after: begin-host-cpu-mhz
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:end-before: end-host-cpu-mhz
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