Add NodeTuning capability to docs

installing/cluster-capabilities.adoc

@@ -62,6 +62,12 @@ include::modules/operator-marketplace.adoc[leveloffset=+2]
 .Additional resources
 * xref:../operators/understanding/olm-rh-catalogs.adoc#olm-rh-catalogs[Red Hat-provided Operator catalogs]
 
+include::modules/node-tuning-operator-capability.adoc[leveloffset=+2]
+
+[role="_additional-resources"]
+.Additional resources
+* xref:../scalability_and_performance/using-node-tuning-operator.adoc#using-node-tuning-operator[Using the Node Tuning Operator]
+
 include::modules/cluster-samples-operator.adoc[leveloffset=+2]
 
 [role="_additional-resources"]

modules/node-tuning-operator.adoc

@@ -10,6 +10,10 @@ endif::[]
 ifeval::["{context}" == "node-tuning-operator"]
 :perf:
 endif::[]
+ifeval::["{context}" == "cluster-capabilities"]
+:cluster-caps:
+endif::[]
+
 
 :_content-type: CONCEPT
 [id="about-node-tuning-operator_{context}"]
@@ -23,8 +27,18 @@ ifdef::operators[]
 [discrete]
 == Purpose
 endif::operators[]
+
+ifdef::cluster-caps[]
+The Node Tuning Operator provides the features for the `NodeTuning` capability.
+endif::cluster-caps[]
+
 The Node Tuning Operator helps you manage node-level tuning by orchestrating the TuneD daemon and achieves low latency performance by using the Performance Profile controller. The majority of high-performance applications require some level of kernel tuning. The Node Tuning Operator provides a unified management interface to users of node-level sysctls and more flexibility to add custom tuning specified by user needs.
 
+ifdef::cluster-caps[]
+If you disable the NodeTuning capability, some tuning settings will not be applied to the control-plane Nodes which may limit the scalability and performance of large clusters with over 900 Nodes or 900 Routes.
+endif::[]
+
+ifndef::cluster-caps[]
 The Operator manages the containerized TuneD daemon for {product-title} as a Kubernetes daemon set. It ensures the custom tuning specification is passed to all containerized TuneD daemons running in the cluster in the format that the daemons understand. The daemons run on all nodes in the cluster, one per node.
 
 Node-level settings applied by the containerized TuneD daemon are rolled back on an event that triggers a profile change or when the containerized TuneD daemon is terminated gracefully by receiving and handling a termination signal.
@@ -41,6 +55,7 @@ The Node Tuning Operator is part of a standard {product-title} installation in v
 ====
 In earlier versions of {product-title}, the Performance Addon Operator was used to implement automatic tuning to achieve low latency performance for OpenShift applications. In {product-title} 4.11 and later, this functionality is part of the Node Tuning Operator.
 ====
+endif::cluster-caps[]
 
 ifdef::operators[]
 [discrete]

snippets/capabilities-table.adoc

@@ -16,6 +16,9 @@ The following table describes the `baselineCapabilitySet` values.
 |`v4.12`
 |Specify when you want the capabilities recommended in {product-title} 4.12 and not automatically enable capabilities, which might be introduced in later versions. The capabilities recommended in {product-title} 4.12 are `baremetal`, `marketplace`, `openshift-samples`, `Console`, `Insights`, `Storage` and `CSISnapshot`. 
 
+|`v4.13`
+|Specify when you want the capabilities recommended in {product-title} 4.13 and not automatically enable capabilities, which might be introduced in later versions. The capabilities recommended in {product-title} 4.12 are `baremetal`, `marketplace`, `openshift-samples`, `Console`, `Insights`, `Storage`, `CSISnapshot` and `Nodetuning`. 
+
 |`None`
 |Specify when the other sets are too large, and you do not need any capabilities or want to fine-tune via `additionalEnabledCapabilities`.