Update pod priority and preemption user docs

content/en/docs/concepts/configuration/pod-priority-preemption.md

@@ -9,22 +9,45 @@ weight: 70
 
 {{% capture overview %}}
 
-{{< feature-state state="alpha" >}}
+{{< feature-state state="beta" >}}
 
 [Pods](/docs/user-guide/pods) in Kubernetes 1.8 and later can have priority. Priority
 indicates the importance of a Pod relative to other Pods. When a Pod cannot be scheduled,
 the scheduler tries to preempt (evict) lower priority Pods to make scheduling of the
 pending Pod possible. In Kubernetes 1.9 and later, Priority also affects scheduling
 order of Pods and out-of-resource eviction ordering on the Node.
 
+Pod priority and preemption are moved to beta since Kubernetes 1.11 and are enabled by default in
+this release and later.
+
+{{< note >}}
+**Note**: Pod priority and preemption were in alpha and not enabled by default in older versions of
+Kubernetes. To use these features in the older versions of Kubernetes, follow the instructions in the
+documentation for your Kubernetes version.
+{{< /note >}}
+
+| Kubernetes Version | Priority and Preemption State | Enabled by default |
+| -------- |:-----:|:----:|
+| 1.8      | alpha |   no |
+| 1.9      | alpha |   no |
+| 1.10     | alpha |   no |
+| 1.11     | beta  |  yes |
+
+{{< warning >}}
+**Warning**: In a cluster where not all users are trusted, a malicious
+user could create pods at the highest possible priorities, causing
+other pods to be evicted/not get scheduled. To resolve this issue,
+[ResourceQuota](https://kubernetes.io/docs/concepts/policy/resource-quotas/) is augmented to support
+Pod priority. An admin can create ResourceQuota for users at specific priority levels, preventing
+them from creating pods at high priorities. However, this feature is in alpha as of Kubernetes 1.11.
+{{< /warning >}}
+
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 {{% capture body %}}
 
 ## How to use priority and preemption
-To use priority and preemption in Kubernetes 1.8 and later, follow these steps:
-
-1. Enable the feature.
+To use priority and preemption in Kubernetes 1.11 and later, follow these steps:
 
 1. Add one or more PriorityClasses.
 
@@ -34,23 +57,7 @@ Of course you do not need to create the Pods directly; normally you would add
 
 The following sections provide more information about these steps.
 
-## Enabling priority and preemption
-
-Pod priority and preemption is disabled by default in Kubernetes 1.8.
-To enable the feature, set this command-line flag for the API server, scheduler and kubelet:
-
-```
---feature-gates=PodPriority=true
-```
-
-Also enable scheduling.k8s.io/v1alpha1 API and Priority [admission controller](/docs/admin/admission-controllers/) in API server:
-
-
-```
---runtime-config=scheduling.k8s.io/v1alpha1=true --enable-admission-plugins=Controller-Foo,Controller-Bar,...,Priority
-```
-
-After the feature is enabled, you can create [PriorityClasses](#priorityclass)
+You can create [PriorityClasses](#priorityclass)
 and create Pods with [`priorityClassName`](#pod-priority) set.
 
 If you try the feature and then decide to disable it, you must remove the PodPriority
@@ -61,9 +68,15 @@ cannot set `priorityClassName` in new Pods.
 
 ## How to disable preemption
 
+**Note**: In Kubernetes 1.11, critical pods (except DaemonSet pods, which are
+still scheduled by the DaemonSet controller) rely on scheduler preemption to be
+scheduled when a cluster is under resource pressure. For this reason, we do not
+recommend disabling this feature. If you still have to disable this feature,
+follow the instructions below.
+
 In Kubernetes 1.11 and later, preemption is controlled by a kube-scheduler flag `disablePreemption`, which is set to `false` by default.
 
-If you want to disable preemption, just set `disablePreemption` to true. This will keep pod priority enabled while preemption is disabled. Here is a sample configuration:
+If you have to disable preemption, just set `disablePreemption` to true. This will keep pod priority enabled while preemption is disabled. Here is a sample configuration:
 
 ```yaml
 apiVersion: componentconfig/v1alpha1
@@ -77,7 +90,7 @@ disablePreemption: true
 
 ```
 
-Please note: although preemption of scheduler is enabled by default, preemption will not happen if `PodPriority` feature is not available.
+Please note: although preemption of scheduler is enabled by default, preemption will not happen if `PodPriority` feature is disabled.
 
 ## PriorityClass