Exclude IOWait time from the CPU total

This affects the following two metrics:

* `system.cpu.total.pct`
* `system.cpu.total.norm.pct`

Fixes #7627.

CHANGELOG.asciidoc

@@ -49,6 +49,7 @@ https://github.com/elastic/beats/compare/v6.2.3...master[Check the HEAD diff]
 - Change http/server metricset to put events by default under http.server and prefix config options with server.. {pull}7100[7100]
 - Disable dedotting in docker module configuration. This will change the out-of-the-box behaviour, but not the one of already configured instances. {pull}7485[7485]
 - Fix typo in etcd/self metricset fields from *.bandwithrate to *.bandwidthrate. {pull}7456[7456]
+- Changed the definition of the `system.cpu.total.pct` and `system.cpu.total.norm.cou` fields to exclude the IOWait time. {pull}7691[7691]
 
 *Packetbeat*
 

libbeat/metric/system/cpu/cpu.go

@@ -116,7 +116,8 @@ func cpuPercentages(s0, s1 *sigar.Cpu, numCPU int) Percentages {
 	}
 
 	calculateTotalPct := func() float64 {
-		return common.Round(float64(numCPU)-calculatePct(s0.Idle, s1.Idle), common.DefaultDecimalPlacesCount)
+		idle := calculatePct(s0.Idle, s1.Idle) + calculatePct(s0.Wait, s1.Wait)
+		return common.Round(float64(numCPU)-idle, common.DefaultDecimalPlacesCount)
 	}
 
 	return Percentages{

metricbeat/docs/fields.asciidoc

@@ -15459,7 +15459,7 @@ type: scaled_float
 
 format: percent
 
-The percentage of CPU time spent in non-idle state.
+The percentage of CPU time spent in states other than Idle and IOWait.
 
 
 --
@@ -15567,17 +15567,7 @@ type: scaled_float
 
 format: percent
 
-The percentage of CPU time spent in non-idle state.
-
-
---
-
-*`system.cpu.total.value`*::
-+
---
-type: long
-
-The value of CPU usage since starting the process.
+The percentage of CPU time in states other than Idle and IOWait, normalised by the number of cores.
 
 
 --

metricbeat/module/system/cpu/_meta/fields.yml

@@ -69,7 +69,7 @@
       type: scaled_float
       format: percent
       description: >
-        The percentage of CPU time spent in non-idle state.
+        The percentage of CPU time spent in states other than Idle and IOWait.
 
     # Normalized Percentages
     - name: user.norm.pct
@@ -126,14 +126,7 @@
       type: scaled_float
       format: percent
       description: >
-        The percentage of CPU time spent in non-idle state.
-
-
-    # Total
-    - name: total.value
-      type: long
-      description: >
-        The value of CPU usage since starting the process.
+        The percentage of CPU time in states other than Idle and IOWait, normalised by the number of cores.
 
 
     # Ticks