Merge "Updated host-update max_cpu_frequency parameter"

doc/source/node_management/kubernetes/host-cpu-mhz-parameters-configuration-d9ccf907ede0.rst

@@ -0,0 +1,69 @@
+.. _host-cpu-mhz-parameters-configuration-d9ccf907ede0:
+
+=====================================
+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
+:command:`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_percentage`` defines 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.
+
+    ..  Note::
+         Run the Linux command :command:`sudo cpupower info` on the host, to
+         determine if the host has support for this configuration.
+
+    .. code-block:: none
+
+        ~(keystone_admin)] $ system service-parameter-modify platform config cpu_max_freq_min_percentage=<value-between-60-100>
+
+    .. note::
+        This parameter can be set between 60% and 100%.
+
+-   Configure ``max_cpu_mhz_configured`` to specify a maximum frequency for a
+    particular host's CPU cores.
+
+    .. code-block:: none
+
+        ~(keystone_admin)] $ system host-update <worker> max_cpu_mhz_configured=<frequency-in-MHz>
+
+-   To restore a host's CPU cores' ``max_cpu_mhz_configured`` value to it's
+    default value, the ``max_cpu_mhz_allowed`` label can be passed to the
+    :command:`host-update` command.
+
+    .. code-block:: none
+
+        ~(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 ``cpu_max_freq_min_percentage``.
+
+.. figure:: figures/CPUFrequencyCustom.png
+   :scale: 100%
+
+.. figure:: figures/CPUFrequencyDefault.png
+   :scale: 100%

doc/source/node_management/kubernetes/host_inventory/hosts-tab.rst

@@ -139,7 +139,7 @@ A sample **Hosts** tab is illustrated below:
     The **Edit Host** button displays the Edit Host window, as illustrated
     below for a worker node:
 
-    .. figure:: /node_management/kubernetes/figures/gkb1569351598356.png
+    .. figure:: /node_management/kubernetes/figures/CPUFrequencyDefault.png
         :scale: 100%
 
     This is the same window you use to assign the host's personality when
@@ -154,6 +154,12 @@ A sample **Hosts** tab is illustrated below:
 
         -   **Host Name**: Hostname of the host.
 
+        -  **CPU Frequency Configuration**: Configure a host's CPU cores maximum
+           frequency. If you select the **Custom** option,  a dropbox to edit the
+           host's Max CPU Frequency will be opened or selecting the **Default**
+           option, the host's Max CPU Frequency will be restored to the
+           ``max_cpu_mhz_allowed`` value.
+
         -   **Location**: Type a physical location for the host to help
             identify the host.
 

doc/source/node_management/kubernetes/index-node-mgmt-kub-5ff5993b9c60.rst

@@ -88,15 +88,16 @@ Common host tasks using the CLI
    common_host_tasks/resetting-a-host-using-the-cli
    common_host_tasks/deleting-a-host-using-the-cli
 
---------------------------------
+------------------------------
-Configuring CPU core assignments
+Configuring CPU core behaviour
---------------------------------
+------------------------------
 
 .. toctree::
    :maxdepth: 1
 
    configuring_cpu_core_assignments/configuring-cpu-core-assignments
    configuring_cpu_core_assignments/changing-the-hyper-threading-status
+   host-cpu-mhz-parameters-configuration-d9ccf907ede0
 
 ------------------------
 Host memory provisioning
@@ -403,3 +404,4 @@ Provision BMC using the CLI
    provisioning_bmc/provisioning-bmc-when-adding-a-host
    provisioning_bmc/provisioning-bmc-after-adding-a-host
    provisioning_bmc/deprovisioning-board-management-control-from-the-cli
+