Add documentation on deploying with custom tuned profiles

Change-Id: If4298a186933a7662de9548a6d602df7c9eeff22
Related-Bug: #1800232

doc/source/install/advanced_deployment/features.rst

@@ -31,3 +31,4 @@ Documentation on how to enable and configure various features available in
    rhsm
    designate
    multiple_overclouds
+   tuned

doc/source/install/advanced_deployment/tuned.rst

@@ -0,0 +1,61 @@
+Deploying custom tuned profiles
+===============================
+
+TripleO can be used to deploy Overcloud nodes with different tuned
+profiles in addition to custom tuned profiles.
+
+Deploying with existing tuned profiles
+--------------------------------------
+
+Create an environment file, e.g. `~/tuned.yaml`, with the following
+content:
+
+.. code-block:: yaml
+
+    parameter_defaults:
+      TunedProfileName: throughput-performance
+
+Deploy the Overcloud as usual using the :doc:`CLI
+<../basic_deployment/basic_deployment_cli>` and pass the environment
+file using the `-e` option:
+
+.. code-block:: bash
+
+  openstack overcloud deploy --templates -e ~/tuned.yaml
+
+In the above example, the `throughput-performance` tuned profile will
+be applied to the overcloud nodes. The TunedProfileName parameter may
+be set to any tuned profile already on the node.
+
+Deploying with custom tuned profiles
+------------------------------------
+
+If the tuned profile you wish to apply is not already on the overcloud
+node being deployed, then TripleO can create the tuned profile for
+you and will set the name of the new profile to whatever
+TunedProfileName parameter you supply.
+
+The following example creates a custom tuned profile called
+`my_profile` which inherits from the existing throughput-performance
+tuned profile and then adds a few extra tunings:
+
+.. code-block:: yaml
+
+    parameter_defaults:
+      TunedCustomProfile: |
+        [main]
+        summary=my profile
+        include=throughput-performance
+        [sysctl]
+        vm.dirty_ratio = 10
+        vm.dirty_background_ratio = 3
+        [sysfs]
+        /sys/kernel/mm/ksm/run=0
+      TunedProfileName: my_profile
+
+The above will create the file `/etc/tuned/my_profile/tuned.conf`
+on the overcloud nodes and tuned.conf will contain the tuned
+directives defined by the TunedCustomProfile parameter. The
+TunedCustomProfile parameter should be set to a multiline string using
+YAML's literal block scalar (i.e. the pipe '|') and that string should
+contain valid tuned directives in INI format.