Explain system host-cpu-modify behaviour (r8, dsr8MR3, dsr8MR2+,r9 )

Added steps for configuring CPU core assignments using CLI

Change-Id: If88f922aba739ef835b29a16aa96d88bacc69183
Signed-off-by: Ngairangbam Mili <ngairangbam.mili@windriver.com>

doc/source/node_management/kubernetes/configuring_cpu_core_assignments/configuring-cpu-core-assignments-using-cli-96ee12bdfc83.rst

@@ -0,0 +1,79 @@
+.. _configuring-cpu-core-assignments-using-cli-96ee12bdfc83:
+
+==========================================
+Configuring CPU Core Assignments Using CLI
+==========================================
+
+You can improve the performance and capacity of specific functions by assigning
+more CPU cores using the following command:
+
+.. code-block:: none
+
+    [sysadmin@controller-0 ~(keystone_admin)]$ system host-cpu-modify [--nowrap] -f <function> [-c <cpulist>] [-p0 <num_cores_on_processor0>] [-p1 <num_cores_on_processor1>] [-p2 <num_cores_on_processor2>] [-p3 <num_cores_on_processor3>] <hostnameorid>
+
+``function``
+
+Use this command with the ``-f`` argument, which specifies the function, such
+as **platform** and **application-isolated** whose core count is to be modified.
+
+.. note::
+
+    Any core that is not specified as one of these functions will be considered
+    as an application core.
+
+**Platform**
+    You can reserve one or more cores per |NUMA| node for platform use.
+    One core on each host is required to run the operating system and
+    associated services. For a combined controller and worker node in a
+    |prod| |AIO-SX| or |AIO-DX| configuration, two cores are required.
+
+    The ability to assign platform cores to specific |NUMA| nodes offers
+    increased flexibility for high-performance configurations. For example, you
+    can dedicate certain |NUMA| nodes for platform use such that other |NUMA|
+    nodes that service |IRQ| requests are available for the containers (hosted
+    applications) that require high-performance |IRQ| servicing.
+
+    .. note::
+
+        If you plan on running the |prefix|-openstack application on an
+        |AIO-SX| or |AIO-DX| deployment, at least 4 platform cores are required
+        for adequate Horizon Web Interface and CLI performance and 6 platform
+        cores are recommended.
+
+**Application-isolated**
+    You can isolate a core from the host process scheduler by specifying the
+    **application-isolated** function. This minimizes interruptions by other tasks to ensure
+    more predictable latency.
+
+    .. note::
+
+        The tasks on the isolated cores will not be automatically load-balanced
+        by the Linux task scheduler. Thus, it is up to the application to affine
+        tasks appropriately.
+
+``cpulist``
+
+Use this option with the ``-c`` argument. This option specifies an explicit list of CPUs.
+
+.. note::
+
+    Only one CPU function can be specified with the ``-c`` option. The ``c`` option
+    must be used in the final call to :command:`system host-cpu-modify`. Unlike specifying
+    by core counts, when using the ``-c`` option, sysinv will not automatically add
+    in any unspecified |SMT| hyperthreads if the host has hyperthreading enabled.
+    It is up to the caller to ensure that all sibling threads are included in the CPU list.
+
+``num_cores_on_processor``
+
+Use this option with the ``-pX`` argument where ``X`` represents the NUMA
+node whose count you want to modify. Multiple unique ``-pX`` arguments may be
+specified, with a core count for each NUMA node.
+
+``hostnameorid``
+
+This is the name or ID of a host.
+
+
+
+
+

doc/source/node_management/kubernetes/configuring_cpu_core_assignments/configuring-cpu-core-assignments.rst

@@ -2,9 +2,9 @@
 .. epz1565872908287
 .. _configuring-cpu-core-assignments:
 
-==============================
+============================================
-Configure CPU Core Assignments
+Configure CPU Core Assignments Using Horizon
-==============================
+============================================
 
 You can improve the performance and capacity of specific functions by assigning
 them more CPU cores from the Horizon Web interface.

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

@@ -96,6 +96,7 @@ Configuring CPU core behaviour
    :maxdepth: 1
 
    configuring_cpu_core_assignments/configuring-cpu-core-assignments
+   configuring_cpu_core_assignments/configuring-cpu-core-assignments-using-cli-96ee12bdfc83
    configuring_cpu_core_assignments/changing-the-hyper-threading-status
    host-cpu-mhz-parameters-configuration-d9ccf907ede0
    single-physical-core-for-platform-function-in-all-in-one-deployments-bec61d5a13f4