Add basic slabinfo metadata. (#15484)

Also adds a new category for Linux kernel metrics that are intrinsic to
the kernel itself.

collectors/slabinfo.plugin/metadata.yaml

@@ -2,30 +2,46 @@ meta:
   plugin_name: slabinfo.plugin
   module_name: slabinfo.plugin
   monitored_instance:
-    name: slabinfo
+    name: Linux kernel SLAB allocator statistics
     link: ''
-    categories: []
-    icon_filename: ''
+    categories:
+      - data-collection.linux-systems.kernel-metrics
+    icon_filename: 'microchip.png'
   related_resources:
     integrations:
       list: []
   info_provided_to_referring_integrations:
     description: ''
-  keywords: []
+  keywords:
+    - linux kernel
+    - slab
+    - slub
+    - slob
+    - slabinfo
   most_popular: false
 overview:
   data_collection:
-    metrics_description: ''
+    metrics_description: >
+      Collects metrics on kernel SLAB cache utilization to monitor the low-level performance impact of workloads
+      in the kernel.
     method_description: ''
   supported_platforms:
-    include: []
+    include:
+      - Linux
     exclude: []
-  multi_instance: true
+  multi_instance: false
   additional_permissions:
-    description: ''
+    description: >
+      This integration requires read access to `/proc/slabinfo`, which is accessible only to the root user by
+      default. Netdata uses Linux Capabilities to give the plugin access to this file. `CAP_DAC_READ_SEARCH`
+      is added automatically during installation. This capability allows bypassing file read permission checks
+      and directory read and execute permission checks. If file capabilities are not usable, then the plugin is
+      instead installed with the SUID bit set in permissions sVko that it runs as root.
   default_behavior:
     auto_detection:
-      description: ''
+      description: >
+        Due to the large number of metrics generated by this integration, it is disabled by default and must be
+        manually enabled.
     limits:
       description: ''
     performance_impact:
@@ -56,28 +72,28 @@ metrics:
   folding:
     title: Metrics
     enabled: false
-  description: ""
+  description: "SLAB cache utilization metrics for the whole system."
   availability: []
   scopes:
-  - name: global
-    description: ""
-    labels: []
-    metrics:
-    - name: mem.slabmemory
-      description: Memory Usage
-      unit: "B"
-      chart_type: line
-      dimensions:
-      - name: a dimension per cache
-    - name: mem.slabfilling
-      description: Object Filling
-      unit: "%"
-      chart_type: line
-      dimensions:
-      - name: a dimension per cache
-    - name: mem.slabwaste
-      description: Memory waste
-      unit: "B"
-      chart_type: line
-      dimensions:
-      - name: a dimension per cache
+    - name: global
+      description: ""
+      labels: []
+      metrics:
+        - name: mem.slabmemory
+          description: Memory Usage
+          unit: "B"
+          chart_type: line
+          dimensions:
+            - name: a dimension per cache
+        - name: mem.slabfilling
+          description: Object Filling
+          unit: "%"
+          chart_type: line
+          dimensions:
+            - name: a dimension per cache
+        - name: mem.slabwaste
+          description: Memory waste
+          unit: "B"
+          chart_type: line
+          dimensions:
+            - name: a dimension per cache

integrations/categories.yaml

@@ -162,6 +162,11 @@
               description: ""
               most_popular: false
               children: []
+        - id: data-collection.linux-systems.kernel-metrics
+          name: Kernel Metrics
+          description: ""
+          most_popular: false
+          children: []
     - id: data-collection.notifications
       name: Notifications
       description: ""