From 5e91c1226f54ba26c95c10efe09a18b78964d42c Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Tue, 26 Dec 2023 21:05:25 +0800
Subject: [PATCH 01/26] Download psi.go from
 https://github.com/gridscale/linux-psi-telegraf-plugin

---
 plugins/inputs/psi/psi.go | 197 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 197 insertions(+)
 create mode 100644 plugins/inputs/psi/psi.go

diff --git a/plugins/inputs/psi/psi.go b/plugins/inputs/psi/psi.go
new file mode 100644
index 0000000000000..fc84abe9482c1
--- /dev/null
+++ b/plugins/inputs/psi/psi.go
@@ -0,0 +1,197 @@
+package psi
+
+import (
+	"log"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+	"github.com/prometheus/procfs"
+)
+
+// Psi - Plugins main structure
+
+type Psi struct{}
+
+// Description returns the plugin description
+func (psi *Psi) Description() string {
+	return `
+    A plugin to gather resource pressure metrics from the Linux kernel.
+    Pressure Stall Information (PSI) is available at
+    "/proc/pressure/" -- cpu, memory and io.
+    
+    Examples:
+    /proc/pressure/cpu
+    some avg10=1.53 avg60=1.87 avg300=1.73 total=1088168194
+    
+    /proc/pressure/memory
+    some avg10=0.00 avg60=0.00 avg300=0.00 total=3463792
+    full avg10=0.00 avg60=0.00 avg300=0.00 total=1429641
+    
+    /proc/pressure/io
+    some avg10=0.00 avg60=0.00 avg300=0.00 total=68568296
+    full avg10=0.00 avg60=0.00 avg300=0.00 total=54982338
+    `
+}
+
+// SampleConfig returns sample configuration for this plugin
+func (psi *Psi) SampleConfig() string {
+	return `
+    [[inputs.execd]]
+    command = ["/usr/local/bin/psi"]
+    signal = "none"
+    `
+}
+
+// Gather Psi metrics
+func (psi *Psi) Gather(acc telegraf.Accumulator) error {
+
+	cpuPressure, memoryPressure, ioPressure, err := psi.getPressureValues()
+	if err == nil {
+		psi.uploadPressure(cpuPressure, memoryPressure, ioPressure, acc)
+	}
+
+	return nil
+}
+
+// run initially when the package is imported
+func init() {
+	inputs.Add("psi", func() telegraf.Input { return &Psi{} })
+}
+
+// getPressureValues - Get the pressure values from /proc/pressure/*
+func (psi *Psi) getPressureValues() (cpuPressure procfs.PSIStats, memoryPressure procfs.PSIStats, ioPressure procfs.PSIStats, err error) {
+	procfs, err := procfs.NewFS("/proc")
+	if err != nil {
+		log.Fatalf("proc not available: %s", err)
+	}
+
+	cpuPressure, err = procfs.PSIStatsForResource("cpu")
+	if err != nil {
+		log.Fatalf("No CPU pressure found: %s", err)
+	}
+
+	memoryPressure, err = procfs.PSIStatsForResource("memory")
+	if err != nil {
+		log.Fatalf("No memory pressure found: %s", err)
+	}
+
+	ioPressure, err = procfs.PSIStatsForResource("io")
+	if err != nil {
+		log.Fatalf("No io pressure found: %s", err)
+	}
+
+	return cpuPressure, memoryPressure, ioPressure, nil
+
+}
+
+// uploadPressure Uploads all pressure value to corrosponding fields
+func (psi *Psi) uploadPressure(cpuPressure procfs.PSIStats, memoryPressure procfs.PSIStats, ioPressure procfs.PSIStats, acc telegraf.Accumulator) {
+
+	// pressureTotal some
+
+	acc.AddCounter("pressureTotal", map[string]interface{}{
+		"total": cpuPressure.Some.Total,
+	},
+		map[string]string{
+			"resource": "cpu",
+			"type":     "some",
+		},
+	)
+
+	acc.AddCounter("pressureTotal", map[string]interface{}{
+		"total": memoryPressure.Some.Total,
+	},
+		map[string]string{
+			"resource": "memory",
+			"type":     "some",
+		},
+	)
+
+	acc.AddCounter("pressureTotal", map[string]interface{}{
+		"total": ioPressure.Some.Total,
+	},
+		map[string]string{
+			"resource": "io",
+			"type":     "some",
+		},
+	)
+
+	// pressureTotal full
+
+	acc.AddCounter("pressureTotal", map[string]interface{}{
+		"total": memoryPressure.Full.Total,
+	},
+		map[string]string{
+			"resource": "memory",
+			"type":     "full",
+		},
+	)
+
+	acc.AddCounter("pressureTotal", map[string]interface{}{
+		"total": ioPressure.Full.Total,
+	},
+		map[string]string{
+			"resource": "io",
+			"type":     "full",
+		},
+	)
+
+	// pressure some
+
+	acc.AddGauge("pressure", map[string]interface{}{
+		"avg10":  cpuPressure.Some.Avg10,
+		"avg60":  cpuPressure.Some.Avg60,
+		"avg300": cpuPressure.Some.Avg300,
+	},
+		map[string]string{
+			"resource": "cpu",
+			"type":     "some",
+		},
+	)
+
+	acc.AddGauge("pressure", map[string]interface{}{
+		"avg10":  memoryPressure.Some.Avg10,
+		"avg60":  memoryPressure.Some.Avg60,
+		"avg300": memoryPressure.Some.Avg300,
+	},
+		map[string]string{
+			"resource": "memory",
+			"type":     "some",
+		},
+	)
+
+	acc.AddGauge("pressure", map[string]interface{}{
+		"avg10":  ioPressure.Some.Avg10,
+		"avg60":  ioPressure.Some.Avg60,
+		"avg300": ioPressure.Some.Avg300,
+	},
+		map[string]string{
+			"resource": "io",
+			"type":     "some",
+		},
+	)
+
+	// pressure full
+
+	acc.AddGauge("pressure", map[string]interface{}{
+		"avg10":  memoryPressure.Full.Avg10,
+		"avg60":  memoryPressure.Full.Avg60,
+		"avg300": memoryPressure.Full.Avg300,
+	},
+		map[string]string{
+			"resource": "memory",
+			"type":     "full",
+		},
+	)
+
+	acc.AddGauge("pressure", map[string]interface{}{
+		"avg10":  ioPressure.Full.Avg10,
+		"avg60":  ioPressure.Full.Avg60,
+		"avg300": ioPressure.Full.Avg300,
+	},
+		map[string]string{
+			"resource": "io",
+			"type":     "full",
+		},
+	)
+}

From 4b91d153f5876e80ad92c08f5df9db59c6127556 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Tue, 26 Dec 2023 21:22:20 +0800
Subject: [PATCH 02/26] psi: Split up psi.go, add sample.conf and README

---
 plugins/inputs/psi/README.md       |  17 +++
 plugins/inputs/psi/psi.go          | 191 ++---------------------------
 plugins/inputs/psi/psi_linux.go    | 162 ++++++++++++++++++++++++
 plugins/inputs/psi/psi_nonlinux.go |  10 ++
 plugins/inputs/psi/sample.conf     |   4 +
 5 files changed, 206 insertions(+), 178 deletions(-)
 create mode 100644 plugins/inputs/psi/README.md
 create mode 100644 plugins/inputs/psi/psi_linux.go
 create mode 100644 plugins/inputs/psi/psi_nonlinux.go
 create mode 100644 plugins/inputs/psi/sample.conf

diff --git a/plugins/inputs/psi/README.md b/plugins/inputs/psi/README.md
new file mode 100644
index 0000000000000..aa82bc4cd00f2
--- /dev/null
+++ b/plugins/inputs/psi/README.md
@@ -0,0 +1,17 @@
+# Pressure Stall Information (PSI) Input Plugin
+
+A plugin to gather resource pressure metrics from the Linux kernel.
+Pressure Stall Information (PSI) is available at
+"/proc/pressure/" -- cpu, memory and io.
+
+Examples:
+/proc/pressure/cpu
+some avg10=1.53 avg60=1.87 avg300=1.73 total=1088168194
+
+/proc/pressure/memory
+some avg10=0.00 avg60=0.00 avg300=0.00 total=3463792
+full avg10=0.00 avg60=0.00 avg300=0.00 total=1429641
+
+/proc/pressure/io
+some avg10=0.00 avg60=0.00 avg300=0.00 total=68568296
+full avg10=0.00 avg60=0.00 avg300=0.00 total=54982338
diff --git a/plugins/inputs/psi/psi.go b/plugins/inputs/psi/psi.go
index fc84abe9482c1..1d2901c0a30b6 100644
--- a/plugins/inputs/psi/psi.go
+++ b/plugins/inputs/psi/psi.go
@@ -1,197 +1,32 @@
 package psi
 
 import (
-	"log"
+	_ "embed"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs"
-	"github.com/prometheus/procfs"
 )
 
 // Psi - Plugins main structure
-
-type Psi struct{}
-
-// Description returns the plugin description
-func (psi *Psi) Description() string {
-	return `
-    A plugin to gather resource pressure metrics from the Linux kernel.
-    Pressure Stall Information (PSI) is available at
-    "/proc/pressure/" -- cpu, memory and io.
-    
-    Examples:
-    /proc/pressure/cpu
-    some avg10=1.53 avg60=1.87 avg300=1.73 total=1088168194
-    
-    /proc/pressure/memory
-    some avg10=0.00 avg60=0.00 avg300=0.00 total=3463792
-    full avg10=0.00 avg60=0.00 avg300=0.00 total=1429641
-    
-    /proc/pressure/io
-    some avg10=0.00 avg60=0.00 avg300=0.00 total=68568296
-    full avg10=0.00 avg60=0.00 avg300=0.00 total=54982338
-    `
+type Psi struct {
+	Log telegraf.Logger `toml:"-"`
 }
 
+//go:embed sample.conf
+var sampleConfig string
+
 // SampleConfig returns sample configuration for this plugin
 func (psi *Psi) SampleConfig() string {
-	return `
-    [[inputs.execd]]
-    command = ["/usr/local/bin/psi"]
-    signal = "none"
-    `
+	return sampleConfig
 }
 
-// Gather Psi metrics
-func (psi *Psi) Gather(acc telegraf.Accumulator) error {
-
-	cpuPressure, memoryPressure, ioPressure, err := psi.getPressureValues()
-	if err == nil {
-		psi.uploadPressure(cpuPressure, memoryPressure, ioPressure, acc)
-	}
-
-	return nil
+// Description returns the plugin description
+func (psi *Psi) Description() string {
+	return "Gather Pressure Stall Information (PSI) from /proc/pressure/"
 }
 
-// run initially when the package is imported
 func init() {
-	inputs.Add("psi", func() telegraf.Input { return &Psi{} })
-}
-
-// getPressureValues - Get the pressure values from /proc/pressure/*
-func (psi *Psi) getPressureValues() (cpuPressure procfs.PSIStats, memoryPressure procfs.PSIStats, ioPressure procfs.PSIStats, err error) {
-	procfs, err := procfs.NewFS("/proc")
-	if err != nil {
-		log.Fatalf("proc not available: %s", err)
-	}
-
-	cpuPressure, err = procfs.PSIStatsForResource("cpu")
-	if err != nil {
-		log.Fatalf("No CPU pressure found: %s", err)
-	}
-
-	memoryPressure, err = procfs.PSIStatsForResource("memory")
-	if err != nil {
-		log.Fatalf("No memory pressure found: %s", err)
-	}
-
-	ioPressure, err = procfs.PSIStatsForResource("io")
-	if err != nil {
-		log.Fatalf("No io pressure found: %s", err)
-	}
-
-	return cpuPressure, memoryPressure, ioPressure, nil
-
-}
-
-// uploadPressure Uploads all pressure value to corrosponding fields
-func (psi *Psi) uploadPressure(cpuPressure procfs.PSIStats, memoryPressure procfs.PSIStats, ioPressure procfs.PSIStats, acc telegraf.Accumulator) {
-
-	// pressureTotal some
-
-	acc.AddCounter("pressureTotal", map[string]interface{}{
-		"total": cpuPressure.Some.Total,
-	},
-		map[string]string{
-			"resource": "cpu",
-			"type":     "some",
-		},
-	)
-
-	acc.AddCounter("pressureTotal", map[string]interface{}{
-		"total": memoryPressure.Some.Total,
-	},
-		map[string]string{
-			"resource": "memory",
-			"type":     "some",
-		},
-	)
-
-	acc.AddCounter("pressureTotal", map[string]interface{}{
-		"total": ioPressure.Some.Total,
-	},
-		map[string]string{
-			"resource": "io",
-			"type":     "some",
-		},
-	)
-
-	// pressureTotal full
-
-	acc.AddCounter("pressureTotal", map[string]interface{}{
-		"total": memoryPressure.Full.Total,
-	},
-		map[string]string{
-			"resource": "memory",
-			"type":     "full",
-		},
-	)
-
-	acc.AddCounter("pressureTotal", map[string]interface{}{
-		"total": ioPressure.Full.Total,
-	},
-		map[string]string{
-			"resource": "io",
-			"type":     "full",
-		},
-	)
-
-	// pressure some
-
-	acc.AddGauge("pressure", map[string]interface{}{
-		"avg10":  cpuPressure.Some.Avg10,
-		"avg60":  cpuPressure.Some.Avg60,
-		"avg300": cpuPressure.Some.Avg300,
-	},
-		map[string]string{
-			"resource": "cpu",
-			"type":     "some",
-		},
-	)
-
-	acc.AddGauge("pressure", map[string]interface{}{
-		"avg10":  memoryPressure.Some.Avg10,
-		"avg60":  memoryPressure.Some.Avg60,
-		"avg300": memoryPressure.Some.Avg300,
-	},
-		map[string]string{
-			"resource": "memory",
-			"type":     "some",
-		},
-	)
-
-	acc.AddGauge("pressure", map[string]interface{}{
-		"avg10":  ioPressure.Some.Avg10,
-		"avg60":  ioPressure.Some.Avg60,
-		"avg300": ioPressure.Some.Avg300,
-	},
-		map[string]string{
-			"resource": "io",
-			"type":     "some",
-		},
-	)
-
-	// pressure full
-
-	acc.AddGauge("pressure", map[string]interface{}{
-		"avg10":  memoryPressure.Full.Avg10,
-		"avg60":  memoryPressure.Full.Avg60,
-		"avg300": memoryPressure.Full.Avg300,
-	},
-		map[string]string{
-			"resource": "memory",
-			"type":     "full",
-		},
-	)
-
-	acc.AddGauge("pressure", map[string]interface{}{
-		"avg10":  ioPressure.Full.Avg10,
-		"avg60":  ioPressure.Full.Avg60,
-		"avg300": ioPressure.Full.Avg300,
-	},
-		map[string]string{
-			"resource": "io",
-			"type":     "full",
-		},
-	)
+	inputs.Add("psi", func() telegraf.Input {
+		return &Psi{}
+	})
 }
diff --git a/plugins/inputs/psi/psi_linux.go b/plugins/inputs/psi/psi_linux.go
new file mode 100644
index 0000000000000..777a5bd3f3ffd
--- /dev/null
+++ b/plugins/inputs/psi/psi_linux.go
@@ -0,0 +1,162 @@
+package psi
+
+import (
+	"fmt"
+
+	"github.com/influxdata/telegraf"
+	"github.com/prometheus/procfs"
+)
+
+// Gather Psi metrics
+func (psi *Psi) Gather(acc telegraf.Accumulator) error {
+	cpuPressure, memoryPressure, ioPressure, err := psi.getPressureValues()
+	if err != nil {
+		return err
+	}
+
+	psi.uploadPressure(cpuPressure, memoryPressure, ioPressure, acc)
+	return nil
+}
+
+// getPressureValues - Get the pressure values from /proc/pressure/*
+func (psi *Psi) getPressureValues() (cpuPressure procfs.PSIStats, memoryPressure procfs.PSIStats, ioPressure procfs.PSIStats, err error) {
+	var fs procfs.FS
+	fs, err = procfs.NewDefaultFS()
+	if err != nil {
+		err = fmt.Errorf("procfs not available: %w", err)
+		return
+	}
+
+	cpuPressure, err = fs.PSIStatsForResource("cpu")
+	if err != nil {
+		err = fmt.Errorf("no CPU pressure found: %w", err)
+		return
+	}
+
+	memoryPressure, err = fs.PSIStatsForResource("memory")
+	if err != nil {
+		err = fmt.Errorf("no memory pressure found: %w", err)
+		return
+	}
+
+	ioPressure, err = fs.PSIStatsForResource("io")
+	if err != nil {
+		err = fmt.Errorf("no io pressure found: %w", err)
+		return
+	}
+
+	return
+}
+
+// uploadPressure Uploads all pressure value to corrosponding fields
+func (psi *Psi) uploadPressure(cpuPressure procfs.PSIStats, memoryPressure procfs.PSIStats, ioPressure procfs.PSIStats, acc telegraf.Accumulator) {
+
+	// pressureTotal some
+
+	acc.AddCounter("pressureTotal", map[string]interface{}{
+		"total": cpuPressure.Some.Total,
+	},
+		map[string]string{
+			"resource": "cpu",
+			"type":     "some",
+		},
+	)
+
+	acc.AddCounter("pressureTotal", map[string]interface{}{
+		"total": memoryPressure.Some.Total,
+	},
+		map[string]string{
+			"resource": "memory",
+			"type":     "some",
+		},
+	)
+
+	acc.AddCounter("pressureTotal", map[string]interface{}{
+		"total": ioPressure.Some.Total,
+	},
+		map[string]string{
+			"resource": "io",
+			"type":     "some",
+		},
+	)
+
+	// pressureTotal full
+
+	acc.AddCounter("pressureTotal", map[string]interface{}{
+		"total": memoryPressure.Full.Total,
+	},
+		map[string]string{
+			"resource": "memory",
+			"type":     "full",
+		},
+	)
+
+	acc.AddCounter("pressureTotal", map[string]interface{}{
+		"total": ioPressure.Full.Total,
+	},
+		map[string]string{
+			"resource": "io",
+			"type":     "full",
+		},
+	)
+
+	// pressure some
+
+	acc.AddGauge("pressure", map[string]interface{}{
+		"avg10":  cpuPressure.Some.Avg10,
+		"avg60":  cpuPressure.Some.Avg60,
+		"avg300": cpuPressure.Some.Avg300,
+	},
+		map[string]string{
+			"resource": "cpu",
+			"type":     "some",
+		},
+	)
+
+	acc.AddGauge("pressure", map[string]interface{}{
+		"avg10":  memoryPressure.Some.Avg10,
+		"avg60":  memoryPressure.Some.Avg60,
+		"avg300": memoryPressure.Some.Avg300,
+	},
+		map[string]string{
+			"resource": "memory",
+			"type":     "some",
+		},
+	)
+
+	acc.AddGauge("pressure", map[string]interface{}{
+		"avg10":  ioPressure.Some.Avg10,
+		"avg60":  ioPressure.Some.Avg60,
+		"avg300": ioPressure.Some.Avg300,
+	},
+		map[string]string{
+			"resource": "io",
+			"type":     "some",
+		},
+	)
+
+	// pressure full
+	// NOTE: cpu.full is omitted because it is always zero
+
+	acc.AddGauge("pressure", map[string]interface{}{
+		"avg10":  memoryPressure.Full.Avg10,
+		"avg60":  memoryPressure.Full.Avg60,
+		"avg300": memoryPressure.Full.Avg300,
+	},
+		map[string]string{
+			"resource": "memory",
+			"type":     "full",
+		},
+	)
+
+	acc.AddGauge("pressure", map[string]interface{}{
+		"avg10":  ioPressure.Full.Avg10,
+		"avg60":  ioPressure.Full.Avg60,
+		"avg300": ioPressure.Full.Avg300,
+	},
+		map[string]string{
+			"resource": "io",
+			"type":     "full",
+		},
+	)
+}
diff --git a/plugins/inputs/psi/psi_nonlinux.go b/plugins/inputs/psi/psi_nonlinux.go
new file mode 100644
index 0000000000000..76e5b74c18096
--- /dev/null
+++ b/plugins/inputs/psi/psi_nonlinux.go
@@ -0,0 +1,10 @@
+//go:build !linux
+
+package psi
+
+import "github.com/influxdata/telegraf"
+
+func (psi *Psi) Gather(_ telegraf.Accumulator) error {
+	psi.Log.Warn("Pressure Stall Information is only supported on Linux")
+	return nil
+}
diff --git a/plugins/inputs/psi/sample.conf b/plugins/inputs/psi/sample.conf
new file mode 100644
index 0000000000000..caa38b909d02f
--- /dev/null
+++ b/plugins/inputs/psi/sample.conf
@@ -0,0 +1,4 @@
+# Read metrics about Pressure Stall Information (PSI)
+# This plugin ONLY supports Linux v4.20+
+[[inputs.psi]]
+  # no configuration

From df37b003afd447eaa0b41f78d08a8f7af04a0c61 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Tue, 26 Dec 2023 21:27:48 +0800
Subject: [PATCH 03/26] Cleanup psi_linux.go, add inputs/all/psi.go

---
 plugins/inputs/all/psi.go       |   5 +
 plugins/inputs/psi/psi_linux.go | 184 ++++++++++----------------------
 2 files changed, 62 insertions(+), 127 deletions(-)
 create mode 100644 plugins/inputs/all/psi.go

diff --git a/plugins/inputs/all/psi.go b/plugins/inputs/all/psi.go
new file mode 100644
index 0000000000000..db54970f1d925
--- /dev/null
+++ b/plugins/inputs/all/psi.go
@@ -0,0 +1,5 @@
+//go:build !custom || inputs || inputs.psi
+
+package all
+
+import _ "github.com/influxdata/telegraf/plugins/inputs/psi" // register plugin
diff --git a/plugins/inputs/psi/psi_linux.go b/plugins/inputs/psi/psi_linux.go
index 777a5bd3f3ffd..dde0c6bd773ca 100644
--- a/plugins/inputs/psi/psi_linux.go
+++ b/plugins/inputs/psi/psi_linux.go
@@ -9,154 +9,84 @@ import (
 
 // Gather Psi metrics
 func (psi *Psi) Gather(acc telegraf.Accumulator) error {
-	cpuPressure, memoryPressure, ioPressure, err := psi.getPressureValues()
+	pressures, err := psi.getPressureValues()
 	if err != nil {
 		return err
 	}
-
-	psi.uploadPressure(cpuPressure, memoryPressure, ioPressure, acc)
+	psi.uploadPressure(pressures, acc)
 	return nil
 }
 
 // getPressureValues - Get the pressure values from /proc/pressure/*
-func (psi *Psi) getPressureValues() (cpuPressure procfs.PSIStats, memoryPressure procfs.PSIStats, ioPressure procfs.PSIStats, err error) {
+func (psi *Psi) getPressureValues() (pressures map[string]procfs.PSIStats, err error) {
 	var fs procfs.FS
 	fs, err = procfs.NewDefaultFS()
 	if err != nil {
-		err = fmt.Errorf("procfs not available: %w", err)
-		return
-	}
-
-	cpuPressure, err = fs.PSIStatsForResource("cpu")
-	if err != nil {
-		err = fmt.Errorf("no CPU pressure found: %w", err)
-		return
+		return nil, fmt.Errorf("procfs not available: %w", err)
 	}
 
-	memoryPressure, err = fs.PSIStatsForResource("memory")
-	if err != nil {
-		err = fmt.Errorf("no memory pressure found: %w", err)
-		return
-	}
-
-	ioPressure, err = fs.PSIStatsForResource("io")
-	if err != nil {
-		err = fmt.Errorf("no io pressure found: %w", err)
-		return
+	pressures = make(map[string]procfs.PSIStats)
+	for _, resource := range []string{"cpu", "memory", "io"} {
+		pressures[resource], err = fs.PSIStatsForResource(resource)
+		if err != nil {
+			return nil, fmt.Errorf("failed to read %s pressure: %w", resource, err)
+		}
 	}
-
-	return
+	return pressures, nil
 }
 
 // uploadPressure Uploads all pressure value to corrosponding fields
-func (psi *Psi) uploadPressure(cpuPressure procfs.PSIStats, memoryPressure procfs.PSIStats, ioPressure procfs.PSIStats, acc telegraf.Accumulator) {
-
-	// pressureTotal some
-
-	acc.AddCounter("pressureTotal", map[string]interface{}{
-		"total": cpuPressure.Some.Total,
-	},
-		map[string]string{
-			"resource": "cpu",
-			"type":     "some",
-		},
-	)
-
-	acc.AddCounter("pressureTotal", map[string]interface{}{
-		"total": memoryPressure.Some.Total,
-	},
-		map[string]string{
-			"resource": "memory",
-			"type":     "some",
-		},
-	)
-
-	acc.AddCounter("pressureTotal", map[string]interface{}{
-		"total": ioPressure.Some.Total,
-	},
-		map[string]string{
-			"resource": "io",
-			"type":     "some",
+// NOTE: resource=cpu,type=full is omitted because it is always zero
+func (psi *Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Accumulator) {
+	// pressureTotal type=some
+	for _, resource := range []string{"cpu", "memory", "io"} {
+		acc.AddCounter("pressureTotal", map[string]interface{}{
+			"total": pressures[resource].Some.Total,
 		},
-	)
-
-	// pressureTotal full
-
-	acc.AddCounter("pressureTotal", map[string]interface{}{
-		"total": memoryPressure.Full.Total,
-	},
-		map[string]string{
-			"resource": "memory",
-			"type":     "full",
-		},
-	)
-
-	acc.AddCounter("pressureTotal", map[string]interface{}{
-		"total": ioPressure.Full.Total,
-	},
-		map[string]string{
-			"resource": "io",
-			"type":     "full",
-		},
-	)
-
-	// pressure some
-
-	acc.AddGauge("pressure", map[string]interface{}{
-		"avg10":  cpuPressure.Some.Avg10,
-		"avg60":  cpuPressure.Some.Avg60,
-		"avg300": cpuPressure.Some.Avg300,
-	},
-		map[string]string{
-			"resource": "cpu",
-			"type":     "some",
-		},
-	)
-
-	acc.AddGauge("pressure", map[string]interface{}{
-		"avg10":  memoryPressure.Some.Avg10,
-		"avg60":  memoryPressure.Some.Avg60,
-		"avg300": memoryPressure.Some.Avg300,
-	},
-		map[string]string{
-			"resource": "memory",
-			"type":     "some",
-		},
-	)
+			map[string]string{
+				"resource": resource,
+				"type":     "some",
+			},
+		)
+	}
 
-	acc.AddGauge("pressure", map[string]interface{}{
-		"avg10":  ioPressure.Some.Avg10,
-		"avg60":  ioPressure.Some.Avg60,
-		"avg300": ioPressure.Some.Avg300,
-	},
-		map[string]string{
-			"resource": "io",
-			"type":     "some",
+	// pressureTotal type=full
+	for _, resource := range []string{"memory", "io"} {
+		acc.AddCounter("pressureTotal", map[string]interface{}{
+			"total": pressures[resource].Full.Total,
 		},
-	)
-
-	// pressure full
-	// NOTE: cpu.full is omitted because it is always zero
+			map[string]string{
+				"resource": resource,
+				"type":     "full",
+			},
+		)
+	}
 
-	acc.AddGauge("pressure", map[string]interface{}{
-		"avg10":  memoryPressure.Full.Avg10,
-		"avg60":  memoryPressure.Full.Avg60,
-		"avg300": memoryPressure.Full.Avg300,
-	},
-		map[string]string{
-			"resource": "memory",
-			"type":     "full",
+	// pressure type=some
+	for _, resource := range []string{"cpu", "memory", "io"} {
+		acc.AddGauge("pressure", map[string]interface{}{
+			"avg10":  pressures[resource].Some.Avg10,
+			"avg60":  pressures[resource].Some.Avg60,
+			"avg300": pressures[resource].Some.Avg300,
 		},
-	)
+			map[string]string{
+				"resource": resource,
+				"type":     "some",
+			},
+		)
+	}
 
-	acc.AddGauge("pressure", map[string]interface{}{
-		"avg10":  ioPressure.Full.Avg10,
-		"avg60":  ioPressure.Full.Avg60,
-		"avg300": ioPressure.Full.Avg300,
-	},
-		map[string]string{
-			"resource": "io",
-			"type":     "full",
+	// pressure type=full
+	for _, resource := range []string{"memory", "io"} {
+		acc.AddGauge("pressure", map[string]interface{}{
+			"avg10":  pressures[resource].Full.Avg10,
+			"avg60":  pressures[resource].Full.Avg60,
+			"avg300": pressures[resource].Full.Avg300,
 		},
-	)
+			map[string]string{
+				"resource": resource,
+				"type":     "full",
+			},
+		)
+	}
 }

From 800c09bda86f0b90ada989d24eb05d29cbc8ba06 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Tue, 26 Dec 2023 21:34:20 +0800
Subject: [PATCH 04/26] psi: Polish README

---
 plugins/inputs/psi/README.md   | 61 ++++++++++++++++++++++++++++++----
 plugins/inputs/psi/sample.conf |  2 +-
 2 files changed, 56 insertions(+), 7 deletions(-)

diff --git a/plugins/inputs/psi/README.md b/plugins/inputs/psi/README.md
index aa82bc4cd00f2..c2d9cba72c6e1 100644
--- a/plugins/inputs/psi/README.md
+++ b/plugins/inputs/psi/README.md
@@ -1,17 +1,66 @@
 # Pressure Stall Information (PSI) Input Plugin
 
-A plugin to gather resource pressure metrics from the Linux kernel.
-Pressure Stall Information (PSI) is available at
-"/proc/pressure/" -- cpu, memory and io.
+A plugin to gather Pressure Stall Information from the Linux kernel from `/proc/pressure/{cpu,memory,io}`.
+
+Kernel version 4.20 or later is required.
 
 Examples:
-/proc/pressure/cpu
+
+```shell
+# /proc/pressure/cpu
 some avg10=1.53 avg60=1.87 avg300=1.73 total=1088168194
 
-/proc/pressure/memory
+# /proc/pressure/memory
 some avg10=0.00 avg60=0.00 avg300=0.00 total=3463792
 full avg10=0.00 avg60=0.00 avg300=0.00 total=1429641
 
-/proc/pressure/io
+# /proc/pressure/io
 some avg10=0.00 avg60=0.00 avg300=0.00 total=68568296
 full avg10=0.00 avg60=0.00 avg300=0.00 total=54982338
+```
+
+## Global configuration options <!-- @/docs/includes/plugin_config.md -->
+
+In addition to the plugin-specific configuration settings, plugins support
+additional global and plugin configuration settings. These settings are used to
+modify metrics, tags, and field or create aliases and configure ordering, etc.
+See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
+
+[CONFIGURATION.md]: ../../../docs/CONFIGURATION.md#plugins
+
+## Configuration
+
+```toml @sample.conf
+# Read metrics about Pressure Stall Information (PSI)
+# Requires Linux kernel v4.20+
+[[inputs.psi]]
+  # no configuration
+```
+
+## Metrics
+
+- pressure
+  - tags:
+    - resource: cpu, memory, or io
+    - type: some or full
+  - fields: avg10, avg60, avg300 for 10-second, 1-minute, and 5-minute averages
+- pressureTotal
+  - tags: same as pressure
+  - fields: total
+
+Note that the combination for `resource=cpu,type=full` is omitted because it is always zero.
+
+## Example Output
+
+```text
+pressure,resource=cpu,type=some avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
+pressure,resource=memory,type=some avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
+pressure,resource=memory,type=full avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
+pressure,resource=io,type=some avg10=21.35,avg60=19.23,avg300=13.48 1700000000000000000
+pressure,resource=io,type=full avg10=21.26,avg60=19.10,avg300=13.39 1700000000000000000
+pressureTotal,resource=cpu,type=some total=657544125 1700000000000000000
+pressureTotal,resource=memory,type=some total=62167126 1700000000000000000
+pressureTotal,resource=memory,type=full total=60968885 1700000000000000000
+pressureTotal,resource=io,type=some total=6507666709 1700000000000000000
+pressureTotal,resource=io,type=full total=6399637024 1700000000000000000
+```
diff --git a/plugins/inputs/psi/sample.conf b/plugins/inputs/psi/sample.conf
index caa38b909d02f..a789656271498 100644
--- a/plugins/inputs/psi/sample.conf
+++ b/plugins/inputs/psi/sample.conf
@@ -1,4 +1,4 @@
 # Read metrics about Pressure Stall Information (PSI)
-# This plugin ONLY supports Linux v4.20+
+# Requires Linux kernel v4.20+
 [[inputs.psi]]
   # no configuration

From a9e061a139bee6803ab3874333b39f1af6ed8561 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Tue, 26 Dec 2023 21:44:48 +0800
Subject: [PATCH 05/26] psi: Add unit test with go:build linux

---
 plugins/inputs/psi/psi_linux.go |  2 +-
 plugins/inputs/psi/psi_test.go  | 75 +++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+), 1 deletion(-)
 create mode 100644 plugins/inputs/psi/psi_test.go

diff --git a/plugins/inputs/psi/psi_linux.go b/plugins/inputs/psi/psi_linux.go
index dde0c6bd773ca..b9f1515b93104 100644
--- a/plugins/inputs/psi/psi_linux.go
+++ b/plugins/inputs/psi/psi_linux.go
@@ -37,7 +37,7 @@ func (psi *Psi) getPressureValues() (pressures map[string]procfs.PSIStats, err e
 
 // uploadPressure Uploads all pressure value to corrosponding fields
 // NOTE: resource=cpu,type=full is omitted because it is always zero
-func (psi *Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Accumulator) {
+func (*Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Accumulator) {
 	// pressureTotal type=some
 	for _, resource := range []string{"cpu", "memory", "io"} {
 		acc.AddCounter("pressureTotal", map[string]interface{}{
diff --git a/plugins/inputs/psi/psi_test.go b/plugins/inputs/psi/psi_test.go
new file mode 100644
index 0000000000000..04defc5f3e96f
--- /dev/null
+++ b/plugins/inputs/psi/psi_test.go
@@ -0,0 +1,75 @@
+//go:build linux
+
+package psi
+
+import (
+	"testing"
+
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/prometheus/procfs"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPSIStats(t *testing.T) {
+	var (
+		psi *Psi
+		err error
+		acc testutil.Accumulator
+	)
+
+	mockPressure := &procfs.PSILine{
+		Avg10:  10,
+		Avg60:  60,
+		Avg300: 300,
+		Total:  114514,
+	}
+
+	mockPSIStats := procfs.PSIStats{
+		Some: mockPressure,
+		Full: mockPressure,
+	}
+
+	mockStats := map[string]procfs.PSIStats{
+		"cpu":    mockPSIStats,
+		"memory": mockPSIStats,
+		"io":     mockPSIStats,
+	}
+
+	err = psi.Gather(&acc)
+	require.NoError(t, err)
+
+	pressureFields := map[string]interface{}{
+		"avg10":  float64(10),
+		"avg60":  float64(60),
+		"avg300": float64(300),
+	}
+	pressureTotalFields := map[string]interface{}{
+		"total": uint64(114514),
+	}
+	acc.ClearMetrics()
+	psi.uploadPressure(mockStats, &acc)
+	for _, typ := range []string{"some", "full"} {
+		for _, resource := range []string{"cpu", "memory", "io"} {
+			if resource == "cpu" && typ == "full" {
+				continue
+			}
+
+			// "pressure" should contain what it should
+			acc.AssertContainsTaggedFields(t, "pressure", pressureFields, map[string]string{
+				"resource": resource,
+				"type":     typ,
+			})
+
+			// "pressure" should NOT contain a "total" field
+			acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureTotalFields, map[string]string{
+				"resource": resource,
+				"type":     typ,
+			})
+		}
+	}
+
+	acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureFields, map[string]string{
+		"resource": "cpu",
+		"type":     "full",
+	})
+}

From 9f38df11bc0e26fa3f05b2b07eabb560fae4fc11 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Tue, 26 Dec 2023 21:56:10 +0800
Subject: [PATCH 06/26] inputs/psi: Add credits to
 gridscale/linux-psi-telegraf-plugin

---
 plugins/inputs/psi/README.md    | 4 ++++
 plugins/inputs/psi/psi_linux.go | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/plugins/inputs/psi/README.md b/plugins/inputs/psi/README.md
index c2d9cba72c6e1..c2efd645b84aa 100644
--- a/plugins/inputs/psi/README.md
+++ b/plugins/inputs/psi/README.md
@@ -64,3 +64,7 @@ pressureTotal,resource=memory,type=full total=60968885 1700000000000000000
 pressureTotal,resource=io,type=some total=6507666709 1700000000000000000
 pressureTotal,resource=io,type=full total=6399637024 1700000000000000000
 ```
+
+## Credits
+
+Part of this plugin was derived from [gridscale/linux-psi-telegraf-plugin](https://github.com/gridscale/linux-psi-telegraf-plugin), available under the same MIT license.
diff --git a/plugins/inputs/psi/psi_linux.go b/plugins/inputs/psi/psi_linux.go
index b9f1515b93104..1beb3cfc90e6e 100644
--- a/plugins/inputs/psi/psi_linux.go
+++ b/plugins/inputs/psi/psi_linux.go
@@ -18,7 +18,7 @@ func (psi *Psi) Gather(acc telegraf.Accumulator) error {
 }
 
 // getPressureValues - Get the pressure values from /proc/pressure/*
-func (psi *Psi) getPressureValues() (pressures map[string]procfs.PSIStats, err error) {
+func (*Psi) getPressureValues() (pressures map[string]procfs.PSIStats, err error) {
 	var fs procfs.FS
 	fs, err = procfs.NewDefaultFS()
 	if err != nil {

From c4cb52b69f9bf8cc3c2f368e42717ebccb22638d Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Tue, 26 Dec 2023 22:01:24 +0800
Subject: [PATCH 07/26] chore(README): Linting rules was a bit more stupid than
 I had previously anticipated

---
 plugins/inputs/psi/README.md | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/plugins/inputs/psi/README.md b/plugins/inputs/psi/README.md
index c2efd645b84aa..2ab2f6b98f381 100644
--- a/plugins/inputs/psi/README.md
+++ b/plugins/inputs/psi/README.md
@@ -1,6 +1,7 @@
 # Pressure Stall Information (PSI) Input Plugin
 
-A plugin to gather Pressure Stall Information from the Linux kernel from `/proc/pressure/{cpu,memory,io}`.
+A plugin to gather Pressure Stall Information from the Linux kernel
+from `/proc/pressure/{cpu,memory,io}`.
 
 Kernel version 4.20 or later is required.
 
@@ -48,23 +49,28 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
   - tags: same as pressure
   - fields: total
 
-Note that the combination for `resource=cpu,type=full` is omitted because it is always zero.
+Note that the combination for `resource=cpu,type=full` is omitted because it is
+always zero.
 
 ## Example Output
 
 ```text
-pressure,resource=cpu,type=some avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
+pressure,resource=cpu,type=some avg10=1.53,avg60=1.87,avg300=1.73 1700000000000000000
 pressure,resource=memory,type=some avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
 pressure,resource=memory,type=full avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
-pressure,resource=io,type=some avg10=21.35,avg60=19.23,avg300=13.48 1700000000000000000
-pressure,resource=io,type=full avg10=21.26,avg60=19.10,avg300=13.39 1700000000000000000
-pressureTotal,resource=cpu,type=some total=657544125 1700000000000000000
-pressureTotal,resource=memory,type=some total=62167126 1700000000000000000
-pressureTotal,resource=memory,type=full total=60968885 1700000000000000000
-pressureTotal,resource=io,type=some total=6507666709 1700000000000000000
-pressureTotal,resource=io,type=full total=6399637024 1700000000000000000
+pressure,resource=io,type=some avg10=0.0,avg60=0.0,avg300=0.0 1700000000000000000
+pressure,resource=io,type=full avg10=0.0,avg60=0.0,avg300=0.0 1700000000000000000
+pressureTotal,resource=cpu,type=some total=1088168194 1700000000000000000
+pressureTotal,resource=memory,type=some total=3463792 1700000000000000000
+pressureTotal,resource=memory,type=full total=1429641 1700000000000000000
+pressureTotal,resource=io,type=some total=68568296 1700000000000000000
+pressureTotal,resource=io,type=full total=54982338 1700000000000000000
 ```
 
 ## Credits
 
-Part of this plugin was derived from [gridscale/linux-psi-telegraf-plugin](https://github.com/gridscale/linux-psi-telegraf-plugin), available under the same MIT license.
+Part of this plugin was derived from
+[gridscale/linux-psi-telegraf-plugin][gridscale/linux-psi-telegraf-plugin],
+available under the same MIT license.
+
+[gridscale/linux-psi-telegraf-plugin]: https://github.com/gridscale/linux-psi-telegraf-plugin

From 1becff8d84e9c18209de9fe6aeac910249bad577 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Tue, 26 Dec 2023 22:06:23 +0800
Subject: [PATCH 08/26] psi_linux: Merge type=some and type=full with a for
 loop

---
 plugins/inputs/psi/psi_linux.go | 76 +++++++++++++--------------------
 1 file changed, 30 insertions(+), 46 deletions(-)

diff --git a/plugins/inputs/psi/psi_linux.go b/plugins/inputs/psi/psi_linux.go
index 1beb3cfc90e6e..2017b11a401ae 100644
--- a/plugins/inputs/psi/psi_linux.go
+++ b/plugins/inputs/psi/psi_linux.go
@@ -38,55 +38,39 @@ func (*Psi) getPressureValues() (pressures map[string]procfs.PSIStats, err error
 // uploadPressure Uploads all pressure value to corrosponding fields
 // NOTE: resource=cpu,type=full is omitted because it is always zero
 func (*Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Accumulator) {
-	// pressureTotal type=some
-	for _, resource := range []string{"cpu", "memory", "io"} {
-		acc.AddCounter("pressureTotal", map[string]interface{}{
-			"total": pressures[resource].Some.Total,
-		},
-			map[string]string{
-				"resource": resource,
-				"type":     "some",
-			},
-		)
-	}
-
-	// pressureTotal type=full
-	for _, resource := range []string{"memory", "io"} {
-		acc.AddCounter("pressureTotal", map[string]interface{}{
-			"total": pressures[resource].Full.Total,
-		},
-			map[string]string{
-				"resource": resource,
-				"type":     "full",
-			},
-		)
-	}
-
-	// pressure type=some
-	for _, resource := range []string{"cpu", "memory", "io"} {
-		acc.AddGauge("pressure", map[string]interface{}{
-			"avg10":  pressures[resource].Some.Avg10,
-			"avg60":  pressures[resource].Some.Avg60,
-			"avg300": pressures[resource].Some.Avg300,
-		},
-			map[string]string{
-				"resource": resource,
-				"type":     "some",
+	// pressureTotal
+	for _, typ := range []string{"some", "full"} {
+		for _, resource := range []string{"cpu", "memory", "io"} {
+			if resource == "cpu" && typ == "full" {
+				continue
+			}
+			acc.AddCounter("pressureTotal", map[string]interface{}{
+				"total": pressures[resource].Some.Total,
 			},
-		)
+				map[string]string{
+					"resource": resource,
+					"type":     typ,
+				},
+			)
+		}
 	}
 
-	// pressure type=full
-	for _, resource := range []string{"memory", "io"} {
-		acc.AddGauge("pressure", map[string]interface{}{
-			"avg10":  pressures[resource].Full.Avg10,
-			"avg60":  pressures[resource].Full.Avg60,
-			"avg300": pressures[resource].Full.Avg300,
-		},
-			map[string]string{
-				"resource": resource,
-				"type":     "full",
+	// pressure
+	for _, typ := range []string{"some", "full"} {
+		for _, resource := range []string{"cpu", "memory", "io"} {
+			if resource == "cpu" && typ == "full" {
+				continue
+			}
+			acc.AddGauge("pressure", map[string]interface{}{
+				"avg10":  pressures[resource].Some.Avg10,
+				"avg60":  pressures[resource].Some.Avg60,
+				"avg300": pressures[resource].Some.Avg300,
 			},
-		)
+				map[string]string{
+					"resource": resource,
+					"type":     typ,
+				},
+			)
+		}
 	}
 }

From 0e3042516a32009d4bc3953a3cbf9dea7dd92e48 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Tue, 26 Dec 2023 22:43:26 +0800
Subject: [PATCH 09/26] psi: Add stub unit test for nonlinux

---
 plugins/inputs/psi/psi.go               |  4 ++--
 plugins/inputs/psi/psi_test_nonlinux.go | 21 +++++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 plugins/inputs/psi/psi_test_nonlinux.go

diff --git a/plugins/inputs/psi/psi.go b/plugins/inputs/psi/psi.go
index 1d2901c0a30b6..5192bcec18cb6 100644
--- a/plugins/inputs/psi/psi.go
+++ b/plugins/inputs/psi/psi.go
@@ -16,12 +16,12 @@ type Psi struct {
 var sampleConfig string
 
 // SampleConfig returns sample configuration for this plugin
-func (psi *Psi) SampleConfig() string {
+func (*Psi) SampleConfig() string {
 	return sampleConfig
 }
 
 // Description returns the plugin description
-func (psi *Psi) Description() string {
+func (*Psi) Description() string {
 	return "Gather Pressure Stall Information (PSI) from /proc/pressure/"
 }
 
diff --git a/plugins/inputs/psi/psi_test_nonlinux.go b/plugins/inputs/psi/psi_test_nonlinux.go
new file mode 100644
index 0000000000000..4de5d5cd23ee3
--- /dev/null
+++ b/plugins/inputs/psi/psi_test_nonlinux.go
@@ -0,0 +1,21 @@
+//go:build !linux
+
+package psi
+
+import (
+	"testing"
+
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPSIStats(t *testing.T) {
+	var (
+		psi *Psi
+		err error
+		acc testutil.Accumulator
+	)
+
+	err = psi.Gather(&acc)
+	require.NoError(t, err)
+}

From aab6c83e7a181e53a205946a64b8c81d2293c0d1 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Wed, 27 Dec 2023 16:57:24 +0800
Subject: [PATCH 10/26] fix: (*procfs.PSILine).Full was not used at all

---
 plugins/inputs/psi/psi_linux.go | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/plugins/inputs/psi/psi_linux.go b/plugins/inputs/psi/psi_linux.go
index 2017b11a401ae..458f9c4111bee 100644
--- a/plugins/inputs/psi/psi_linux.go
+++ b/plugins/inputs/psi/psi_linux.go
@@ -44,8 +44,17 @@ func (*Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Ac
 			if resource == "cpu" && typ == "full" {
 				continue
 			}
+
+			var stat *procfs.PSILine
+			switch typ {
+			case "some":
+				stat = pressures[resource].Some
+			case "full":
+				stat = pressures[resource].Full
+			}
+
 			acc.AddCounter("pressureTotal", map[string]interface{}{
-				"total": pressures[resource].Some.Total,
+				"total": stat.Total,
 			},
 				map[string]string{
 					"resource": resource,
@@ -61,10 +70,19 @@ func (*Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Ac
 			if resource == "cpu" && typ == "full" {
 				continue
 			}
+
+			var stat *procfs.PSILine
+			switch typ {
+			case "some":
+				stat = pressures[resource].Some
+			case "full":
+				stat = pressures[resource].Full
+			}
+
 			acc.AddGauge("pressure", map[string]interface{}{
-				"avg10":  pressures[resource].Some.Avg10,
-				"avg60":  pressures[resource].Some.Avg60,
-				"avg300": pressures[resource].Some.Avg300,
+				"avg10":  stat.Avg10,
+				"avg60":  stat.Avg60,
+				"avg300": stat.Avg300,
 			},
 				map[string]string{
 					"resource": resource,

From a1ab1aa92677970f06a7c2317048173bb3158b6a Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Wed, 27 Dec 2023 17:12:41 +0800
Subject: [PATCH 11/26] psi_linux: Merge two loops with same structure

---
 plugins/inputs/psi/psi_linux.go | 39 ++++++++-------------------------
 1 file changed, 9 insertions(+), 30 deletions(-)

diff --git a/plugins/inputs/psi/psi_linux.go b/plugins/inputs/psi/psi_linux.go
index 458f9c4111bee..395032c7db01e 100644
--- a/plugins/inputs/psi/psi_linux.go
+++ b/plugins/inputs/psi/psi_linux.go
@@ -38,13 +38,17 @@ func (*Psi) getPressureValues() (pressures map[string]procfs.PSIStats, err error
 // uploadPressure Uploads all pressure value to corrosponding fields
 // NOTE: resource=cpu,type=full is omitted because it is always zero
 func (*Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Accumulator) {
-	// pressureTotal
 	for _, typ := range []string{"some", "full"} {
 		for _, resource := range []string{"cpu", "memory", "io"} {
 			if resource == "cpu" && typ == "full" {
 				continue
 			}
 
+			tags := map[string]string{
+				"resource": resource,
+				"type":     typ,
+			}
+
 			var stat *procfs.PSILine
 			switch typ {
 			case "some":
@@ -53,42 +57,17 @@ func (*Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Ac
 				stat = pressures[resource].Full
 			}
 
+			// pressureTotal
 			acc.AddCounter("pressureTotal", map[string]interface{}{
 				"total": stat.Total,
-			},
-				map[string]string{
-					"resource": resource,
-					"type":     typ,
-				},
-			)
-		}
-	}
-
-	// pressure
-	for _, typ := range []string{"some", "full"} {
-		for _, resource := range []string{"cpu", "memory", "io"} {
-			if resource == "cpu" && typ == "full" {
-				continue
-			}
-
-			var stat *procfs.PSILine
-			switch typ {
-			case "some":
-				stat = pressures[resource].Some
-			case "full":
-				stat = pressures[resource].Full
-			}
+			}, tags)
 
+			// pressure
 			acc.AddGauge("pressure", map[string]interface{}{
 				"avg10":  stat.Avg10,
 				"avg60":  stat.Avg60,
 				"avg300": stat.Avg300,
-			},
-				map[string]string{
-					"resource": resource,
-					"type":     typ,
-				},
-			)
+			}, tags)
 		}
 	}
 }

From 9107636909e263b1707f2c7fc2fe4d4d31a38901 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Wed, 27 Dec 2023 17:51:21 +0800
Subject: [PATCH 12/26] psi_test: Add supporting tests for
 aab6c83e7a181e53a205946a64b8c81d2293c0d1

---
 plugins/inputs/psi/psi_test.go | 62 ++++++++++++++++++++++------------
 1 file changed, 41 insertions(+), 21 deletions(-)

diff --git a/plugins/inputs/psi/psi_test.go b/plugins/inputs/psi/psi_test.go
index 04defc5f3e96f..d5f5e4db9a4d9 100644
--- a/plugins/inputs/psi/psi_test.go
+++ b/plugins/inputs/psi/psi_test.go
@@ -17,18 +17,22 @@ func TestPSIStats(t *testing.T) {
 		acc testutil.Accumulator
 	)
 
-	mockPressure := &procfs.PSILine{
+	mockPressureSome := &procfs.PSILine{
 		Avg10:  10,
 		Avg60:  60,
 		Avg300: 300,
 		Total:  114514,
 	}
-
+	mockPressureFull := &procfs.PSILine{
+		Avg10:  1,
+		Avg60:  6,
+		Avg300: 30,
+		Total:  11451,
+	}
 	mockPSIStats := procfs.PSIStats{
-		Some: mockPressure,
-		Full: mockPressure,
+		Some: mockPressureSome,
+		Full: mockPressureFull,
 	}
-
 	mockStats := map[string]procfs.PSIStats{
 		"cpu":    mockPSIStats,
 		"memory": mockPSIStats,
@@ -38,14 +42,27 @@ func TestPSIStats(t *testing.T) {
 	err = psi.Gather(&acc)
 	require.NoError(t, err)
 
-	pressureFields := map[string]interface{}{
-		"avg10":  float64(10),
-		"avg60":  float64(60),
-		"avg300": float64(300),
+	pressureFields := map[string]map[string]interface{}{
+		"some": {
+			"avg10":  float64(10),
+			"avg60":  float64(60),
+			"avg300": float64(300),
+		},
+		"full": {
+			"avg10":  float64(1),
+			"avg60":  float64(6),
+			"avg300": float64(30),
+		},
 	}
-	pressureTotalFields := map[string]interface{}{
-		"total": uint64(114514),
+	pressureTotalFields := map[string]map[string]interface{}{
+		"some": {
+			"total": uint64(114514),
+		},
+		"full": {
+			"total": uint64(11451),
+		},
 	}
+
 	acc.ClearMetrics()
 	psi.uploadPressure(mockStats, &acc)
 	for _, typ := range []string{"some", "full"} {
@@ -54,22 +71,25 @@ func TestPSIStats(t *testing.T) {
 				continue
 			}
 
-			// "pressure" should contain what it should
-			acc.AssertContainsTaggedFields(t, "pressure", pressureFields, map[string]string{
+			tags := map[string]string{
 				"resource": resource,
 				"type":     typ,
-			})
+			}
 
-			// "pressure" should NOT contain a "total" field
-			acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureTotalFields, map[string]string{
-				"resource": resource,
-				"type":     typ,
-			})
+			acc.AssertContainsTaggedFields(t, "pressure", pressureFields[typ], tags)
+			acc.AssertContainsTaggedFields(t, "pressureTotal", pressureTotalFields[typ], tags)
+
+			// "pressure" and "pressureTotal" should contain disjoint set of fields
+			acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureTotalFields[typ], tags)
+			acc.AssertDoesNotContainsTaggedFields(t, "pressureTotal", pressureFields[typ], tags)
 		}
 	}
 
-	acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureFields, map[string]string{
+	// The combination "resource=cpu,type=full" should NOT appear anywhere
+	forbiddenTags := map[string]string{
 		"resource": "cpu",
 		"type":     "full",
-	})
+	}
+	acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureFields["full"], forbiddenTags)
+	acc.AssertDoesNotContainsTaggedFields(t, "pressureTotal", pressureTotalFields["full"], forbiddenTags)
 }

From 90335b666f0603dfa2f20bb184e6ab11b388050b Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Tue, 2 Jan 2024 23:32:05 +0800
Subject: [PATCH 13/26] psi: Merge pressure and pressureTotal into one series

---
 plugins/inputs/psi/README.md    | 10 +++++-----
 plugins/inputs/psi/psi_linux.go | 11 +++++++----
 plugins/inputs/psi/psi_test.go  |  9 +++------
 3 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/plugins/inputs/psi/README.md b/plugins/inputs/psi/README.md
index 2ab2f6b98f381..1f868d75874af 100644
--- a/plugins/inputs/psi/README.md
+++ b/plugins/inputs/psi/README.md
@@ -60,11 +60,11 @@ pressure,resource=memory,type=some avg10=0.00,avg60=0.00,avg300=0.00 17000000000
 pressure,resource=memory,type=full avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
 pressure,resource=io,type=some avg10=0.0,avg60=0.0,avg300=0.0 1700000000000000000
 pressure,resource=io,type=full avg10=0.0,avg60=0.0,avg300=0.0 1700000000000000000
-pressureTotal,resource=cpu,type=some total=1088168194 1700000000000000000
-pressureTotal,resource=memory,type=some total=3463792 1700000000000000000
-pressureTotal,resource=memory,type=full total=1429641 1700000000000000000
-pressureTotal,resource=io,type=some total=68568296 1700000000000000000
-pressureTotal,resource=io,type=full total=54982338 1700000000000000000
+pressure,resource=cpu,type=some total=1088168194i 1700000000000000000
+pressure,resource=memory,type=some total=3463792i 1700000000000000000
+pressure,resource=memory,type=full total=1429641i 1700000000000000000
+pressure,resource=io,type=some total=68568296i 1700000000000000000
+pressure,resource=io,type=full total=54982338i 1700000000000000000
 ```
 
 ## Credits
diff --git a/plugins/inputs/psi/psi_linux.go b/plugins/inputs/psi/psi_linux.go
index 395032c7db01e..1e3d05cc2e390 100644
--- a/plugins/inputs/psi/psi_linux.go
+++ b/plugins/inputs/psi/psi_linux.go
@@ -2,6 +2,7 @@ package psi
 
 import (
 	"fmt"
+	"time"
 
 	"github.com/influxdata/telegraf"
 	"github.com/prometheus/procfs"
@@ -57,17 +58,19 @@ func (*Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Ac
 				stat = pressures[resource].Full
 			}
 
-			// pressureTotal
-			acc.AddCounter("pressureTotal", map[string]interface{}{
+			now := time.Now()
+
+			// pressure
+			acc.AddCounter("pressure", map[string]interface{}{
 				"total": stat.Total,
-			}, tags)
+			}, tags, now)
 
 			// pressure
 			acc.AddGauge("pressure", map[string]interface{}{
 				"avg10":  stat.Avg10,
 				"avg60":  stat.Avg60,
 				"avg300": stat.Avg300,
-			}, tags)
+			}, tags, now)
 		}
 	}
 }
diff --git a/plugins/inputs/psi/psi_test.go b/plugins/inputs/psi/psi_test.go
index d5f5e4db9a4d9..889916ec7e452 100644
--- a/plugins/inputs/psi/psi_test.go
+++ b/plugins/inputs/psi/psi_test.go
@@ -42,6 +42,7 @@ func TestPSIStats(t *testing.T) {
 	err = psi.Gather(&acc)
 	require.NoError(t, err)
 
+	// separate fields for gauges and counters
 	pressureFields := map[string]map[string]interface{}{
 		"some": {
 			"avg10":  float64(10),
@@ -77,11 +78,7 @@ func TestPSIStats(t *testing.T) {
 			}
 
 			acc.AssertContainsTaggedFields(t, "pressure", pressureFields[typ], tags)
-			acc.AssertContainsTaggedFields(t, "pressureTotal", pressureTotalFields[typ], tags)
-
-			// "pressure" and "pressureTotal" should contain disjoint set of fields
-			acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureTotalFields[typ], tags)
-			acc.AssertDoesNotContainsTaggedFields(t, "pressureTotal", pressureFields[typ], tags)
+			acc.AssertContainsTaggedFields(t, "pressure", pressureTotalFields[typ], tags)
 		}
 	}
 
@@ -91,5 +88,5 @@ func TestPSIStats(t *testing.T) {
 		"type":     "full",
 	}
 	acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureFields["full"], forbiddenTags)
-	acc.AssertDoesNotContainsTaggedFields(t, "pressureTotal", pressureTotalFields["full"], forbiddenTags)
+	acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureTotalFields["full"], forbiddenTags)
 }

From 4e6cae0691fd185f620b7aaf988df07c981b79f7 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Thu, 4 Jan 2024 18:28:40 +0800
Subject: [PATCH 14/26] inputs/psi: Start migrating PSI code to inputs/kernel

---
 plugins/inputs/kernel/README.md   | 31 ++++++++++++++++++++++++++++++-
 plugins/inputs/kernel/kernel.go   |  7 +++++++
 plugins/inputs/kernel/sample.conf |  1 +
 plugins/inputs/psi/README.md      |  5 +----
 plugins/inputs/psi/psi_linux.go   |  4 ----
 5 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/plugins/inputs/kernel/README.md b/plugins/inputs/kernel/README.md
index 2ea010bc22a01..4b5bc09670a5e 100644
--- a/plugins/inputs/kernel/README.md
+++ b/plugins/inputs/kernel/README.md
@@ -11,7 +11,6 @@ The metrics are documented in `man proc` under the `/proc/stat` section.
 The metrics are documented in `man 4 random` under the `/proc/stat` section.
 
 ```text
-
 /proc/sys/kernel/random/entropy_avail
 Contains the value of available entropy
 
@@ -63,6 +62,7 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
   ## Additional gather options
   ## Possible options include:
   ## * ksm - kernel same-page merging
+  ## * psi - pressure stall information
   # collect = []
 ```
 
@@ -91,11 +91,40 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
   - ksm_stable_node_dups (integer, number of duplicated KSM pages, `stable_node_dups`)
   - ksm_use_zero_pages (integer, whether empty pages should be treated specially, `use_zero_pages`)
 
+- pressure (if `psi` is included in `collect`)
+  - tags:
+    - resource: cpu, memory, or io
+    - type: some or full
+  - fields: avg10, avg60, avg300, total
+
 ## Example Output
 
+Default config:
+
 ```text
 kernel boot_time=1690487872i,context_switches=321398652i,entropy_avail=256i,interrupts=141868628i,processes_forked=946492i 1691339564000000000
+```
+
+If `ksm` is included in `collect`:
 
+```
 kernel boot_time=1690487872i,context_switches=321252729i,entropy_avail=256i,interrupts=141783427i,ksm_full_scans=0i,ksm_max_page_sharing=256i,ksm_merge_across_nodes=1i,ksm_pages_shared=0i,ksm_pages_sharing=0i,ksm_pages_to_scan=100i,ksm_pages_unshared=0i,ksm_pages_volatile=0i,ksm_run=0i,ksm_sleep_millisecs=20i,ksm_stable_node_chains=0i,ksm_stable_node_chains_prune_millisecs=2000i,ksm_stable_node_dups=0i,ksm_use_zero_pages=0i,processes_forked=946467i 1691339522000000000
+```
+
+If `psi` is included in `collect`:
 
+```text
+pressure,resource=cpu,type=some avg10=1.53,avg60=1.87,avg300=1.73 1700000000000000000
+pressure,resource=memory,type=some avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
+pressure,resource=memory,type=full avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
+pressure,resource=io,type=some avg10=0.0,avg60=0.0,avg300=0.0 1700000000000000000
+pressure,resource=io,type=full avg10=0.0,avg60=0.0,avg300=0.0 1700000000000000000
+pressure,resource=cpu,type=some total=1088168194i 1700000000000000000
+pressure,resource=memory,type=some total=3463792i 1700000000000000000
+pressure,resource=memory,type=full total=1429641i 1700000000000000000
+pressure,resource=io,type=some total=68568296i 1700000000000000000
+pressure,resource=io,type=full total=54982338i 1700000000000000000
 ```
+
+Note that the combination for `resource=cpu,type=full` is omitted because it is
+always zero.
diff --git a/plugins/inputs/kernel/kernel.go b/plugins/inputs/kernel/kernel.go
index 9e98bc6e0881f..d7abc1d414a89 100644
--- a/plugins/inputs/kernel/kernel.go
+++ b/plugins/inputs/kernel/kernel.go
@@ -34,6 +34,7 @@ type Kernel struct {
 	statFile        string
 	entropyStatFile string
 	ksmStatsDir     string
+	psiDir          string
 }
 
 func (k *Kernel) Init() error {
@@ -48,6 +49,12 @@ func (k *Kernel) Init() error {
 			return fmt.Errorf("directory %q does not exist. Is KSM enabled in this kernel?", k.ksmStatsDir)
 		}
 	}
+	if k.optCollect["psi"] {
+		if _, err := os.Stat(k.psiDir); os.IsNotExist(err) {
+			// psi probably not supported in the kernel, bail out early
+			return fmt.Errorf("directory %q does not exist. Is PSI enabled in this kernel?", k.psiDir)
+		}
+	}
 	return nil
 }
 
diff --git a/plugins/inputs/kernel/sample.conf b/plugins/inputs/kernel/sample.conf
index bdc3fc053e3c7..d848024360b0c 100644
--- a/plugins/inputs/kernel/sample.conf
+++ b/plugins/inputs/kernel/sample.conf
@@ -4,4 +4,5 @@
   ## Additional gather options
   ## Possible options include:
   ## * ksm - kernel same-page merging
+  ## * psi - pressure stall information
   # collect = []
diff --git a/plugins/inputs/psi/README.md b/plugins/inputs/psi/README.md
index 1f868d75874af..03f3a80ff154b 100644
--- a/plugins/inputs/psi/README.md
+++ b/plugins/inputs/psi/README.md
@@ -44,10 +44,7 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
   - tags:
     - resource: cpu, memory, or io
     - type: some or full
-  - fields: avg10, avg60, avg300 for 10-second, 1-minute, and 5-minute averages
-- pressureTotal
-  - tags: same as pressure
-  - fields: total
+  - fields: avg10, avg60, avg300, total
 
 Note that the combination for `resource=cpu,type=full` is omitted because it is
 always zero.
diff --git a/plugins/inputs/psi/psi_linux.go b/plugins/inputs/psi/psi_linux.go
index 1e3d05cc2e390..a27280e6e9160 100644
--- a/plugins/inputs/psi/psi_linux.go
+++ b/plugins/inputs/psi/psi_linux.go
@@ -59,13 +59,9 @@ func (*Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Ac
 			}
 
 			now := time.Now()
-
-			// pressure
 			acc.AddCounter("pressure", map[string]interface{}{
 				"total": stat.Total,
 			}, tags, now)
-
-			// pressure
 			acc.AddGauge("pressure", map[string]interface{}{
 				"avg10":  stat.Avg10,
 				"avg60":  stat.Avg60,

From 47626a02571c883b3adabfc54c2a99746bacd4d6 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Thu, 4 Jan 2024 18:41:00 +0800
Subject: [PATCH 15/26] Move code from inputs/psi to inputs/kernel

---
 plugins/inputs/all/psi.go                   |  5 --
 plugins/inputs/kernel/README.md             | 18 ++++-
 plugins/inputs/kernel/kernel.go             |  6 ++
 plugins/inputs/{psi => kernel}/psi_linux.go | 12 ++--
 plugins/inputs/{psi => kernel}/psi_test.go  |  8 +--
 plugins/inputs/psi/README.md                | 73 ---------------------
 plugins/inputs/psi/psi.go                   | 32 ---------
 plugins/inputs/psi/psi_nonlinux.go          | 10 ---
 plugins/inputs/psi/psi_test_nonlinux.go     | 21 ------
 plugins/inputs/psi/sample.conf              |  4 --
 10 files changed, 33 insertions(+), 156 deletions(-)
 delete mode 100644 plugins/inputs/all/psi.go
 rename plugins/inputs/{psi => kernel}/psi_linux.go (81%)
 rename plugins/inputs/{psi => kernel}/psi_test.go (95%)
 delete mode 100644 plugins/inputs/psi/README.md
 delete mode 100644 plugins/inputs/psi/psi.go
 delete mode 100644 plugins/inputs/psi/psi_nonlinux.go
 delete mode 100644 plugins/inputs/psi/psi_test_nonlinux.go
 delete mode 100644 plugins/inputs/psi/sample.conf

diff --git a/plugins/inputs/all/psi.go b/plugins/inputs/all/psi.go
deleted file mode 100644
index db54970f1d925..0000000000000
--- a/plugins/inputs/all/psi.go
+++ /dev/null
@@ -1,5 +0,0 @@
-//go:build !custom || inputs || inputs.psi
-
-package all
-
-import _ "github.com/influxdata/telegraf/plugins/inputs/psi" // register plugin
diff --git a/plugins/inputs/kernel/README.md b/plugins/inputs/kernel/README.md
index 4b5bc09670a5e..450d506fb8566 100644
--- a/plugins/inputs/kernel/README.md
+++ b/plugins/inputs/kernel/README.md
@@ -5,7 +5,7 @@ This plugin is only available on Linux.
 The kernel plugin gathers info about the kernel that doesn't fit into other
 plugins. In general, it is the statistics available in `/proc/stat` that are not
 covered by other plugins as well as the value of
-`/proc/sys/kernel/random/entropy_avail` and optionally, Kernel Samepage Merging.
+`/proc/sys/kernel/random/entropy_avail` and optionally, Kernel Samepage Merging and Pressure Stall Information.
 
 The metrics are documented in `man proc` under the `/proc/stat` section.
 The metrics are documented in `man 4 random` under the `/proc/stat` section.
@@ -41,8 +41,24 @@ Number of forks since boot.
 Kernel Samepage Merging is generally documented in [kernel documentation][1] and
 the available metrics exposed via sysfs are documented in [admin guide][2]
 
+Pressure Stall Information is documented in [kernel documentation][3]. Kernel version 4.20 or later is required. Examples of PSI:
+
+```shell
+# /proc/pressure/cpu
+some avg10=1.53 avg60=1.87 avg300=1.73 total=1088168194
+
+# /proc/pressure/memory
+some avg10=0.00 avg60=0.00 avg300=0.00 total=3463792
+full avg10=0.00 avg60=0.00 avg300=0.00 total=1429641
+
+# /proc/pressure/io
+some avg10=0.00 avg60=0.00 avg300=0.00 total=68568296
+full avg10=0.00 avg60=0.00 avg300=0.00 total=54982338
+```
+
 [1]: https://www.kernel.org/doc/html/latest/mm/ksm.html
 [2]: https://www.kernel.org/doc/html/latest/admin-guide/mm/ksm.html#ksm-daemon-sysfs-interface
+[3]: https://www.kernel.org/doc/html/latest/accounting/psi.html
 
 ## Global configuration options <!-- @/docs/includes/plugin_config.md -->
 
diff --git a/plugins/inputs/kernel/kernel.go b/plugins/inputs/kernel/kernel.go
index d7abc1d414a89..a1fa3eafed57d 100644
--- a/plugins/inputs/kernel/kernel.go
+++ b/plugins/inputs/kernel/kernel.go
@@ -152,6 +152,12 @@ func (k *Kernel) Gather(acc telegraf.Accumulator) error {
 	}
 	acc.AddCounter("kernel", fields, map[string]string{})
 
+	if k.optCollect["psi"] {
+		if err := k.gatherPressure(acc); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
diff --git a/plugins/inputs/psi/psi_linux.go b/plugins/inputs/kernel/psi_linux.go
similarity index 81%
rename from plugins/inputs/psi/psi_linux.go
rename to plugins/inputs/kernel/psi_linux.go
index a27280e6e9160..4b33f1b404ffd 100644
--- a/plugins/inputs/psi/psi_linux.go
+++ b/plugins/inputs/kernel/psi_linux.go
@@ -1,4 +1,4 @@
-package psi
+package kernel
 
 import (
 	"fmt"
@@ -9,17 +9,17 @@ import (
 )
 
 // Gather Psi metrics
-func (psi *Psi) Gather(acc telegraf.Accumulator) error {
-	pressures, err := psi.getPressureValues()
+func (k *Kernel) gatherPressure(acc telegraf.Accumulator) error {
+	pressures, err := k.getPressureValues()
 	if err != nil {
 		return err
 	}
-	psi.uploadPressure(pressures, acc)
+	k.uploadPressure(pressures, acc)
 	return nil
 }
 
 // getPressureValues - Get the pressure values from /proc/pressure/*
-func (*Psi) getPressureValues() (pressures map[string]procfs.PSIStats, err error) {
+func (*Kernel) getPressureValues() (pressures map[string]procfs.PSIStats, err error) {
 	var fs procfs.FS
 	fs, err = procfs.NewDefaultFS()
 	if err != nil {
@@ -38,7 +38,7 @@ func (*Psi) getPressureValues() (pressures map[string]procfs.PSIStats, err error
 
 // uploadPressure Uploads all pressure value to corrosponding fields
 // NOTE: resource=cpu,type=full is omitted because it is always zero
-func (*Psi) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Accumulator) {
+func (*Kernel) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Accumulator) {
 	for _, typ := range []string{"some", "full"} {
 		for _, resource := range []string{"cpu", "memory", "io"} {
 			if resource == "cpu" && typ == "full" {
diff --git a/plugins/inputs/psi/psi_test.go b/plugins/inputs/kernel/psi_test.go
similarity index 95%
rename from plugins/inputs/psi/psi_test.go
rename to plugins/inputs/kernel/psi_test.go
index 889916ec7e452..44cffc6ee9f54 100644
--- a/plugins/inputs/psi/psi_test.go
+++ b/plugins/inputs/kernel/psi_test.go
@@ -1,6 +1,6 @@
 //go:build linux
 
-package psi
+package kernel
 
 import (
 	"testing"
@@ -12,7 +12,7 @@ import (
 
 func TestPSIStats(t *testing.T) {
 	var (
-		psi *Psi
+		k   *Kernel
 		err error
 		acc testutil.Accumulator
 	)
@@ -39,7 +39,7 @@ func TestPSIStats(t *testing.T) {
 		"io":     mockPSIStats,
 	}
 
-	err = psi.Gather(&acc)
+	err = k.gatherPressure(&acc)
 	require.NoError(t, err)
 
 	// separate fields for gauges and counters
@@ -65,7 +65,7 @@ func TestPSIStats(t *testing.T) {
 	}
 
 	acc.ClearMetrics()
-	psi.uploadPressure(mockStats, &acc)
+	k.uploadPressure(mockStats, &acc)
 	for _, typ := range []string{"some", "full"} {
 		for _, resource := range []string{"cpu", "memory", "io"} {
 			if resource == "cpu" && typ == "full" {
diff --git a/plugins/inputs/psi/README.md b/plugins/inputs/psi/README.md
deleted file mode 100644
index 03f3a80ff154b..0000000000000
--- a/plugins/inputs/psi/README.md
+++ /dev/null
@@ -1,73 +0,0 @@
-# Pressure Stall Information (PSI) Input Plugin
-
-A plugin to gather Pressure Stall Information from the Linux kernel
-from `/proc/pressure/{cpu,memory,io}`.
-
-Kernel version 4.20 or later is required.
-
-Examples:
-
-```shell
-# /proc/pressure/cpu
-some avg10=1.53 avg60=1.87 avg300=1.73 total=1088168194
-
-# /proc/pressure/memory
-some avg10=0.00 avg60=0.00 avg300=0.00 total=3463792
-full avg10=0.00 avg60=0.00 avg300=0.00 total=1429641
-
-# /proc/pressure/io
-some avg10=0.00 avg60=0.00 avg300=0.00 total=68568296
-full avg10=0.00 avg60=0.00 avg300=0.00 total=54982338
-```
-
-## Global configuration options <!-- @/docs/includes/plugin_config.md -->
-
-In addition to the plugin-specific configuration settings, plugins support
-additional global and plugin configuration settings. These settings are used to
-modify metrics, tags, and field or create aliases and configure ordering, etc.
-See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
-
-[CONFIGURATION.md]: ../../../docs/CONFIGURATION.md#plugins
-
-## Configuration
-
-```toml @sample.conf
-# Read metrics about Pressure Stall Information (PSI)
-# Requires Linux kernel v4.20+
-[[inputs.psi]]
-  # no configuration
-```
-
-## Metrics
-
-- pressure
-  - tags:
-    - resource: cpu, memory, or io
-    - type: some or full
-  - fields: avg10, avg60, avg300, total
-
-Note that the combination for `resource=cpu,type=full` is omitted because it is
-always zero.
-
-## Example Output
-
-```text
-pressure,resource=cpu,type=some avg10=1.53,avg60=1.87,avg300=1.73 1700000000000000000
-pressure,resource=memory,type=some avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
-pressure,resource=memory,type=full avg10=0.00,avg60=0.00,avg300=0.00 1700000000000000000
-pressure,resource=io,type=some avg10=0.0,avg60=0.0,avg300=0.0 1700000000000000000
-pressure,resource=io,type=full avg10=0.0,avg60=0.0,avg300=0.0 1700000000000000000
-pressure,resource=cpu,type=some total=1088168194i 1700000000000000000
-pressure,resource=memory,type=some total=3463792i 1700000000000000000
-pressure,resource=memory,type=full total=1429641i 1700000000000000000
-pressure,resource=io,type=some total=68568296i 1700000000000000000
-pressure,resource=io,type=full total=54982338i 1700000000000000000
-```
-
-## Credits
-
-Part of this plugin was derived from
-[gridscale/linux-psi-telegraf-plugin][gridscale/linux-psi-telegraf-plugin],
-available under the same MIT license.
-
-[gridscale/linux-psi-telegraf-plugin]: https://github.com/gridscale/linux-psi-telegraf-plugin
diff --git a/plugins/inputs/psi/psi.go b/plugins/inputs/psi/psi.go
deleted file mode 100644
index 5192bcec18cb6..0000000000000
--- a/plugins/inputs/psi/psi.go
+++ /dev/null
@@ -1,32 +0,0 @@
-package psi
-
-import (
-	_ "embed"
-
-	"github.com/influxdata/telegraf"
-	"github.com/influxdata/telegraf/plugins/inputs"
-)
-
-// Psi - Plugins main structure
-type Psi struct {
-	Log telegraf.Logger `toml:"-"`
-}
-
-//go:embed sample.conf
-var sampleConfig string
-
-// SampleConfig returns sample configuration for this plugin
-func (*Psi) SampleConfig() string {
-	return sampleConfig
-}
-
-// Description returns the plugin description
-func (*Psi) Description() string {
-	return "Gather Pressure Stall Information (PSI) from /proc/pressure/"
-}
-
-func init() {
-	inputs.Add("psi", func() telegraf.Input {
-		return &Psi{}
-	})
-}
diff --git a/plugins/inputs/psi/psi_nonlinux.go b/plugins/inputs/psi/psi_nonlinux.go
deleted file mode 100644
index 76e5b74c18096..0000000000000
--- a/plugins/inputs/psi/psi_nonlinux.go
+++ /dev/null
@@ -1,10 +0,0 @@
-//go:build !linux
-
-package psi
-
-import "github.com/influxdata/telegraf"
-
-func (psi *Psi) Gather(_ telegraf.Accumulator) error {
-	psi.Log.Warn("Pressure Stall Information is only supported on Linux")
-	return nil
-}
diff --git a/plugins/inputs/psi/psi_test_nonlinux.go b/plugins/inputs/psi/psi_test_nonlinux.go
deleted file mode 100644
index 4de5d5cd23ee3..0000000000000
--- a/plugins/inputs/psi/psi_test_nonlinux.go
+++ /dev/null
@@ -1,21 +0,0 @@
-//go:build !linux
-
-package psi
-
-import (
-	"testing"
-
-	"github.com/influxdata/telegraf/testutil"
-	"github.com/stretchr/testify/require"
-)
-
-func TestPSIStats(t *testing.T) {
-	var (
-		psi *Psi
-		err error
-		acc testutil.Accumulator
-	)
-
-	err = psi.Gather(&acc)
-	require.NoError(t, err)
-}
diff --git a/plugins/inputs/psi/sample.conf b/plugins/inputs/psi/sample.conf
deleted file mode 100644
index a789656271498..0000000000000
--- a/plugins/inputs/psi/sample.conf
+++ /dev/null
@@ -1,4 +0,0 @@
-# Read metrics about Pressure Stall Information (PSI)
-# Requires Linux kernel v4.20+
-[[inputs.psi]]
-  # no configuration

From c9707550f97e56f9722768e2731f7e2fba01d53b Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Thu, 4 Jan 2024 18:44:03 +0800
Subject: [PATCH 16/26] inputs/kernel: Fix documentation and formatting

---
 plugins/inputs/kernel/README.md | 10 +++++-----
 plugins/inputs/kernel/kernel.go |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/plugins/inputs/kernel/README.md b/plugins/inputs/kernel/README.md
index 450d506fb8566..de07e9f7d97d4 100644
--- a/plugins/inputs/kernel/README.md
+++ b/plugins/inputs/kernel/README.md
@@ -7,8 +7,7 @@ plugins. In general, it is the statistics available in `/proc/stat` that are not
 covered by other plugins as well as the value of
 `/proc/sys/kernel/random/entropy_avail` and optionally, Kernel Samepage Merging and Pressure Stall Information.
 
-The metrics are documented in `man proc` under the `/proc/stat` section.
-The metrics are documented in `man 4 random` under the `/proc/stat` section.
+The metrics are documented in `man 5 proc` under the `/proc/stat` section, as well as `man 4 random` under the `/proc interfaces` section (for `entropy_avail`).
 
 ```text
 /proc/sys/kernel/random/entropy_avail
@@ -41,7 +40,7 @@ Number of forks since boot.
 Kernel Samepage Merging is generally documented in [kernel documentation][1] and
 the available metrics exposed via sysfs are documented in [admin guide][2]
 
-Pressure Stall Information is documented in [kernel documentation][3]. Kernel version 4.20 or later is required. Examples of PSI:
+Pressure Stall Information is exposed through `/proc/pressure` and is documented in [kernel documentation][3]. Kernel version 4.20 or later is required. Examples of PSI:
 
 ```shell
 # /proc/pressure/cpu
@@ -111,7 +110,8 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
   - tags:
     - resource: cpu, memory, or io
     - type: some or full
-  - fields: avg10, avg60, avg300, total
+  - floating-point fields: avg10, avg60, avg300
+  - integer fields: total
 
 ## Example Output
 
@@ -123,7 +123,7 @@ kernel boot_time=1690487872i,context_switches=321398652i,entropy_avail=256i,inte
 
 If `ksm` is included in `collect`:
 
-```
+```text
 kernel boot_time=1690487872i,context_switches=321252729i,entropy_avail=256i,interrupts=141783427i,ksm_full_scans=0i,ksm_max_page_sharing=256i,ksm_merge_across_nodes=1i,ksm_pages_shared=0i,ksm_pages_sharing=0i,ksm_pages_to_scan=100i,ksm_pages_unshared=0i,ksm_pages_volatile=0i,ksm_run=0i,ksm_sleep_millisecs=20i,ksm_stable_node_chains=0i,ksm_stable_node_chains_prune_millisecs=2000i,ksm_stable_node_dups=0i,ksm_use_zero_pages=0i,processes_forked=946467i 1691339522000000000
 ```
 
diff --git a/plugins/inputs/kernel/kernel.go b/plugins/inputs/kernel/kernel.go
index a1fa3eafed57d..1c3ed192315ec 100644
--- a/plugins/inputs/kernel/kernel.go
+++ b/plugins/inputs/kernel/kernel.go
@@ -163,7 +163,7 @@ func (k *Kernel) Gather(acc telegraf.Accumulator) error {
 
 func (k *Kernel) getProcValueBytes(path string) ([]byte, error) {
 	if _, err := os.Stat(path); os.IsNotExist(err) {
-		return nil, fmt.Errorf("Path %q does not exist", path)
+		return nil, fmt.Errorf("path %q does not exist", path)
 	} else if err != nil {
 		return nil, err
 	}

From 69fe9a4515e81a6e36631276c386d06ff3dfca5f Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Thu, 4 Jan 2024 18:54:53 +0800
Subject: [PATCH 17/26] inputs/kernel: Fix README long lines

---
 plugins/inputs/kernel/README.md | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/plugins/inputs/kernel/README.md b/plugins/inputs/kernel/README.md
index de07e9f7d97d4..8b53efa3fc688 100644
--- a/plugins/inputs/kernel/README.md
+++ b/plugins/inputs/kernel/README.md
@@ -5,9 +5,12 @@ This plugin is only available on Linux.
 The kernel plugin gathers info about the kernel that doesn't fit into other
 plugins. In general, it is the statistics available in `/proc/stat` that are not
 covered by other plugins as well as the value of
-`/proc/sys/kernel/random/entropy_avail` and optionally, Kernel Samepage Merging and Pressure Stall Information.
+`/proc/sys/kernel/random/entropy_avail` and optionally, Kernel Samepage Merging
+and Pressure Stall Information.
 
-The metrics are documented in `man 5 proc` under the `/proc/stat` section, as well as `man 4 random` under the `/proc interfaces` section (for `entropy_avail`).
+The metrics are documented in `man 5 proc` under the `/proc/stat` section, as
+well as `man 4 random` under the `/proc interfaces` section
+(for `entropy_avail`).
 
 ```text
 /proc/sys/kernel/random/entropy_avail
@@ -38,9 +41,11 @@ Number of forks since boot.
 ```
 
 Kernel Samepage Merging is generally documented in [kernel documentation][1] and
-the available metrics exposed via sysfs are documented in [admin guide][2]
+the available metrics exposed via sysfs are documented in [admin guide][2].
 
-Pressure Stall Information is exposed through `/proc/pressure` and is documented in [kernel documentation][3]. Kernel version 4.20 or later is required. Examples of PSI:
+Pressure Stall Information is exposed through `/proc/pressure` and is documented
+in [kernel documentation][3]. Kernel version 4.20 or later is required.
+Examples of PSI:
 
 ```shell
 # /proc/pressure/cpu

From bcad0642558cc1b2cdf6c6c2a5744377e1900d95 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Thu, 4 Jan 2024 18:58:26 +0800
Subject: [PATCH 18/26] inputs/kernel: Add initializer value for k.psiDir

---
 plugins/inputs/kernel/kernel.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/plugins/inputs/kernel/kernel.go b/plugins/inputs/kernel/kernel.go
index 1c3ed192315ec..c4197b83f58aa 100644
--- a/plugins/inputs/kernel/kernel.go
+++ b/plugins/inputs/kernel/kernel.go
@@ -196,6 +196,7 @@ func init() {
 			statFile:        "/proc/stat",
 			entropyStatFile: "/proc/sys/kernel/random/entropy_avail",
 			ksmStatsDir:     "/sys/kernel/mm/ksm",
+			psiDir:          "/proc/pressure",
 		}
 	})
 }

From 5da3e6c43112ab1f98ef84016896b19c57553dfd Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Thu, 4 Jan 2024 19:00:01 +0800
Subject: [PATCH 19/26] inputs/kernel: Rename psi_linux.go to psi.go

---
 plugins/inputs/kernel/{psi_linux.go => psi.go} | 2 ++
 1 file changed, 2 insertions(+)
 rename plugins/inputs/kernel/{psi_linux.go => psi.go} (99%)

diff --git a/plugins/inputs/kernel/psi_linux.go b/plugins/inputs/kernel/psi.go
similarity index 99%
rename from plugins/inputs/kernel/psi_linux.go
rename to plugins/inputs/kernel/psi.go
index 4b33f1b404ffd..37a1dd562b62e 100644
--- a/plugins/inputs/kernel/psi_linux.go
+++ b/plugins/inputs/kernel/psi.go
@@ -1,3 +1,5 @@
+//go:build linux
+
 package kernel
 
 import (

From 4537dffd896050f40f178f6e744afd2d4157cf06 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Fri, 5 Jan 2024 01:21:21 +0800
Subject: [PATCH 20/26] Remove trailing punctuations in error messages

---
 plugins/inputs/kernel/kernel.go      | 4 ++--
 plugins/inputs/kernel/kernel_test.go | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/plugins/inputs/kernel/kernel.go b/plugins/inputs/kernel/kernel.go
index c4197b83f58aa..00a81361e6318 100644
--- a/plugins/inputs/kernel/kernel.go
+++ b/plugins/inputs/kernel/kernel.go
@@ -46,13 +46,13 @@ func (k *Kernel) Init() error {
 	if k.optCollect["ksm"] {
 		if _, err := os.Stat(k.ksmStatsDir); os.IsNotExist(err) {
 			// ksm probably not enabled in the kernel, bail out early
-			return fmt.Errorf("directory %q does not exist. Is KSM enabled in this kernel?", k.ksmStatsDir)
+			return fmt.Errorf("directory %q does not exist. KSM is not enabled in this kernel", k.ksmStatsDir)
 		}
 	}
 	if k.optCollect["psi"] {
 		if _, err := os.Stat(k.psiDir); os.IsNotExist(err) {
 			// psi probably not supported in the kernel, bail out early
-			return fmt.Errorf("directory %q does not exist. Is PSI enabled in this kernel?", k.psiDir)
+			return fmt.Errorf("directory %q does not exist. PSI is not enabled in this kernel", k.psiDir)
 		}
 	}
 	return nil
diff --git a/plugins/inputs/kernel/kernel_test.go b/plugins/inputs/kernel/kernel_test.go
index d249e63c8f70b..26fa7dcbe549a 100644
--- a/plugins/inputs/kernel/kernel_test.go
+++ b/plugins/inputs/kernel/kernel_test.go
@@ -200,7 +200,7 @@ func TestKSMEnabledWrongDir(t *testing.T) {
 		ConfigCollect: []string{"ksm"},
 	}
 
-	require.ErrorContains(t, k.Init(), "Is KSM enabled in this kernel?")
+	require.ErrorContains(t, k.Init(), "KSM is not enabled in this kernel")
 }
 
 func TestKSMDisabledNoKSMTags(t *testing.T) {

From 1ea12c2cf4f2151b3bf301fd6dd4b3764d7139ee Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Fri, 5 Jan 2024 03:45:45 +0800
Subject: [PATCH 21/26] Add TestPSIEnabledWrongDir

---
 plugins/inputs/kernel/psi_test.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/plugins/inputs/kernel/psi_test.go b/plugins/inputs/kernel/psi_test.go
index 44cffc6ee9f54..7aca6b3c0bf42 100644
--- a/plugins/inputs/kernel/psi_test.go
+++ b/plugins/inputs/kernel/psi_test.go
@@ -10,6 +10,15 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestPSIEnabledWrongDir(t *testing.T) {
+	k := Kernel{
+		psiDir:        "testdata/this_file_does_not_exist",
+		ConfigCollect: []string{"psi"},
+	}
+
+	require.ErrorContains(t, k.Init(), "PSI is not enabled in this kernel")
+}
+
 func TestPSIStats(t *testing.T) {
 	var (
 		k   *Kernel

From 588f12e28dc277a8de008c9a207c36407c08939e Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Fri, 5 Jan 2024 05:36:26 +0800
Subject: [PATCH 22/26] inputs.kernel: Use k.psiDir for initializing procfs.FS,
 add test data

---
 plugins/inputs/kernel/kernel.go               |  8 +++-
 plugins/inputs/kernel/psi.go                  | 10 +----
 plugins/inputs/kernel/psi_test.go             | 41 ++++---------------
 plugins/inputs/kernel/testdata/pressure/cpu   |  2 +
 plugins/inputs/kernel/testdata/pressure/io    |  2 +
 .../inputs/kernel/testdata/pressure/memory    |  2 +
 6 files changed, 22 insertions(+), 43 deletions(-)
 create mode 100644 plugins/inputs/kernel/testdata/pressure/cpu
 create mode 100644 plugins/inputs/kernel/testdata/pressure/io
 create mode 100644 plugins/inputs/kernel/testdata/pressure/memory

diff --git a/plugins/inputs/kernel/kernel.go b/plugins/inputs/kernel/kernel.go
index 00a81361e6318..b84a54aa7e2cc 100644
--- a/plugins/inputs/kernel/kernel.go
+++ b/plugins/inputs/kernel/kernel.go
@@ -13,6 +13,7 @@ import (
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs"
+	"github.com/prometheus/procfs"
 )
 
 //go:embed sample.conf
@@ -35,6 +36,7 @@ type Kernel struct {
 	entropyStatFile string
 	ksmStatsDir     string
 	psiDir          string
+	procfs          procfs.FS
 }
 
 func (k *Kernel) Init() error {
@@ -50,9 +52,11 @@ func (k *Kernel) Init() error {
 		}
 	}
 	if k.optCollect["psi"] {
-		if _, err := os.Stat(k.psiDir); os.IsNotExist(err) {
+		procdir := filepath.Dir(k.psiDir)
+		var err error
+		if k.procfs, err = procfs.NewFS(procdir); err != nil {
 			// psi probably not supported in the kernel, bail out early
-			return fmt.Errorf("directory %q does not exist. PSI is not enabled in this kernel", k.psiDir)
+			return fmt.Errorf("failed to initialize procfs on %s: %w", procdir, err)
 		}
 	}
 	return nil
diff --git a/plugins/inputs/kernel/psi.go b/plugins/inputs/kernel/psi.go
index 37a1dd562b62e..b8b49cdf6fea9 100644
--- a/plugins/inputs/kernel/psi.go
+++ b/plugins/inputs/kernel/psi.go
@@ -21,16 +21,10 @@ func (k *Kernel) gatherPressure(acc telegraf.Accumulator) error {
 }
 
 // getPressureValues - Get the pressure values from /proc/pressure/*
-func (*Kernel) getPressureValues() (pressures map[string]procfs.PSIStats, err error) {
-	var fs procfs.FS
-	fs, err = procfs.NewDefaultFS()
-	if err != nil {
-		return nil, fmt.Errorf("procfs not available: %w", err)
-	}
-
+func (k *Kernel) getPressureValues() (pressures map[string]procfs.PSIStats, err error) {
 	pressures = make(map[string]procfs.PSIStats)
 	for _, resource := range []string{"cpu", "memory", "io"} {
-		pressures[resource], err = fs.PSIStatsForResource(resource)
+		pressures[resource], err = k.procfs.PSIStatsForResource(resource)
 		if err != nil {
 			return nil, fmt.Errorf("failed to read %s pressure: %w", resource, err)
 		}
diff --git a/plugins/inputs/kernel/psi_test.go b/plugins/inputs/kernel/psi_test.go
index 7aca6b3c0bf42..10f2025e5b2ae 100644
--- a/plugins/inputs/kernel/psi_test.go
+++ b/plugins/inputs/kernel/psi_test.go
@@ -6,50 +6,27 @@ import (
 	"testing"
 
 	"github.com/influxdata/telegraf/testutil"
-	"github.com/prometheus/procfs"
 	"github.com/stretchr/testify/require"
 )
 
 func TestPSIEnabledWrongDir(t *testing.T) {
 	k := Kernel{
-		psiDir:        "testdata/this_file_does_not_exist",
+		psiDir:        "testdata/this_directory_does_not_exist/stub",
 		ConfigCollect: []string{"psi"},
 	}
 
-	require.ErrorContains(t, k.Init(), "PSI is not enabled in this kernel")
+	require.ErrorContains(t, k.Init(), "failed to initialize procfs on ")
 }
 
 func TestPSIStats(t *testing.T) {
-	var (
-		k   *Kernel
-		err error
-		acc testutil.Accumulator
-	)
+	var acc testutil.Accumulator
 
-	mockPressureSome := &procfs.PSILine{
-		Avg10:  10,
-		Avg60:  60,
-		Avg300: 300,
-		Total:  114514,
-	}
-	mockPressureFull := &procfs.PSILine{
-		Avg10:  1,
-		Avg60:  6,
-		Avg300: 30,
-		Total:  11451,
-	}
-	mockPSIStats := procfs.PSIStats{
-		Some: mockPressureSome,
-		Full: mockPressureFull,
-	}
-	mockStats := map[string]procfs.PSIStats{
-		"cpu":    mockPSIStats,
-		"memory": mockPSIStats,
-		"io":     mockPSIStats,
+	k := Kernel{
+		psiDir:        "testdata/pressure",
+		ConfigCollect: []string{"psi"},
 	}
-
-	err = k.gatherPressure(&acc)
-	require.NoError(t, err)
+	require.NoError(t, k.Init())
+	require.NoError(t, k.gatherPressure(&acc))
 
 	// separate fields for gauges and counters
 	pressureFields := map[string]map[string]interface{}{
@@ -73,8 +50,6 @@ func TestPSIStats(t *testing.T) {
 		},
 	}
 
-	acc.ClearMetrics()
-	k.uploadPressure(mockStats, &acc)
 	for _, typ := range []string{"some", "full"} {
 		for _, resource := range []string{"cpu", "memory", "io"} {
 			if resource == "cpu" && typ == "full" {
diff --git a/plugins/inputs/kernel/testdata/pressure/cpu b/plugins/inputs/kernel/testdata/pressure/cpu
new file mode 100644
index 0000000000000..1093304726260
--- /dev/null
+++ b/plugins/inputs/kernel/testdata/pressure/cpu
@@ -0,0 +1,2 @@
+some avg10=10.00 avg60=60.00 avg300=300.00 total=114514
+full avg10=0.00 avg60=0.00 avg300=0.00 total=0
diff --git a/plugins/inputs/kernel/testdata/pressure/io b/plugins/inputs/kernel/testdata/pressure/io
new file mode 100644
index 0000000000000..613432c83cacb
--- /dev/null
+++ b/plugins/inputs/kernel/testdata/pressure/io
@@ -0,0 +1,2 @@
+some avg10=10.00 avg60=60.00 avg300=300.00 total=114514
+full avg10=1.00 avg60=6.00 avg300=30.00 total=11451
diff --git a/plugins/inputs/kernel/testdata/pressure/memory b/plugins/inputs/kernel/testdata/pressure/memory
new file mode 100644
index 0000000000000..613432c83cacb
--- /dev/null
+++ b/plugins/inputs/kernel/testdata/pressure/memory
@@ -0,0 +1,2 @@
+some avg10=10.00 avg60=60.00 avg300=300.00 total=114514
+full avg10=1.00 avg60=6.00 avg300=30.00 total=11451

From 2067d63648190858ba93c1fec3825fe8c77bc214 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Fri, 5 Jan 2024 05:40:42 +0800
Subject: [PATCH 23/26] inputs.kernel: Merge getPressureValues and
 uploadPressure

---
 plugins/inputs/kernel/psi.go | 44 +++++++++++-------------------------
 1 file changed, 13 insertions(+), 31 deletions(-)

diff --git a/plugins/inputs/kernel/psi.go b/plugins/inputs/kernel/psi.go
index b8b49cdf6fea9..28d54ac3b62a0 100644
--- a/plugins/inputs/kernel/psi.go
+++ b/plugins/inputs/kernel/psi.go
@@ -10,34 +10,23 @@ import (
 	"github.com/prometheus/procfs"
 )
 
-// Gather Psi metrics
+// Gather PSI metrics
 func (k *Kernel) gatherPressure(acc telegraf.Accumulator) error {
-	pressures, err := k.getPressureValues()
-	if err != nil {
-		return err
-	}
-	k.uploadPressure(pressures, acc)
-	return nil
-}
-
-// getPressureValues - Get the pressure values from /proc/pressure/*
-func (k *Kernel) getPressureValues() (pressures map[string]procfs.PSIStats, err error) {
-	pressures = make(map[string]procfs.PSIStats)
 	for _, resource := range []string{"cpu", "memory", "io"} {
-		pressures[resource], err = k.procfs.PSIStatsForResource(resource)
+		now := time.Now()
+		psiStats, err := k.procfs.PSIStatsForResource(resource)
 		if err != nil {
-			return nil, fmt.Errorf("failed to read %s pressure: %w", resource, err)
+			return fmt.Errorf("failed to read %s pressure: %w", resource, err)
 		}
-	}
-	return pressures, nil
-}
 
-// uploadPressure Uploads all pressure value to corrosponding fields
-// NOTE: resource=cpu,type=full is omitted because it is always zero
-func (*Kernel) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf.Accumulator) {
-	for _, typ := range []string{"some", "full"} {
-		for _, resource := range []string{"cpu", "memory", "io"} {
+		stats := map[string]*procfs.PSILine{
+			"some": psiStats.Some,
+			"full": psiStats.Full,
+		}
+
+		for _, typ := range []string{"some", "full"} {
 			if resource == "cpu" && typ == "full" {
+				// resource=cpu,type=full is omitted because it is always zero
 				continue
 			}
 
@@ -45,16 +34,8 @@ func (*Kernel) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf
 				"resource": resource,
 				"type":     typ,
 			}
+			stat := stats[typ]
 
-			var stat *procfs.PSILine
-			switch typ {
-			case "some":
-				stat = pressures[resource].Some
-			case "full":
-				stat = pressures[resource].Full
-			}
-
-			now := time.Now()
 			acc.AddCounter("pressure", map[string]interface{}{
 				"total": stat.Total,
 			}, tags, now)
@@ -65,4 +46,5 @@ func (*Kernel) uploadPressure(pressures map[string]procfs.PSIStats, acc telegraf
 			}, tags, now)
 		}
 	}
+	return nil
 }

From 9261d75aecd8972ae524d0598a979649f19aff4e Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Fri, 5 Jan 2024 18:15:38 +0800
Subject: [PATCH 24/26] Apply suggestions from code review

Co-authored-by: Sven Rebhan <36194019+srebhan@users.noreply.github.com>
---
 plugins/inputs/kernel/kernel.go   |   5 +-
 plugins/inputs/kernel/psi_test.go | 182 ++++++++++++++++++++++--------
 2 files changed, 139 insertions(+), 48 deletions(-)

diff --git a/plugins/inputs/kernel/kernel.go b/plugins/inputs/kernel/kernel.go
index b84a54aa7e2cc..b63f7e2fa6592 100644
--- a/plugins/inputs/kernel/kernel.go
+++ b/plugins/inputs/kernel/kernel.go
@@ -11,9 +11,10 @@ import (
 	"path/filepath"
 	"strconv"
 
+	"github.com/prometheus/procfs"
+	
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs"
-	"github.com/prometheus/procfs"
 )
 
 //go:embed sample.conf
@@ -158,7 +159,7 @@ func (k *Kernel) Gather(acc telegraf.Accumulator) error {
 
 	if k.optCollect["psi"] {
 		if err := k.gatherPressure(acc); err != nil {
-			return err
+			return fmt.Errorf("gathering pressure failed: %w", err)
 		}
 	}
 
diff --git a/plugins/inputs/kernel/psi_test.go b/plugins/inputs/kernel/psi_test.go
index 10f2025e5b2ae..0228b20b3accc 100644
--- a/plugins/inputs/kernel/psi_test.go
+++ b/plugins/inputs/kernel/psi_test.go
@@ -19,58 +19,148 @@ func TestPSIEnabledWrongDir(t *testing.T) {
 }
 
 func TestPSIStats(t *testing.T) {
-	var acc testutil.Accumulator
-
 	k := Kernel{
 		psiDir:        "testdata/pressure",
 		ConfigCollect: []string{"psi"},
 	}
 	require.NoError(t, k.Init())
-	require.NoError(t, k.gatherPressure(&acc))
-
-	// separate fields for gauges and counters
-	pressureFields := map[string]map[string]interface{}{
-		"some": {
-			"avg10":  float64(10),
-			"avg60":  float64(60),
-			"avg300": float64(300),
-		},
-		"full": {
-			"avg10":  float64(1),
-			"avg60":  float64(6),
-			"avg300": float64(30),
-		},
-	}
-	pressureTotalFields := map[string]map[string]interface{}{
-		"some": {
-			"total": uint64(114514),
-		},
-		"full": {
-			"total": uint64(11451),
-		},
-	}
 
-	for _, typ := range []string{"some", "full"} {
-		for _, resource := range []string{"cpu", "memory", "io"} {
-			if resource == "cpu" && typ == "full" {
-				continue
-			}
-
-			tags := map[string]string{
-				"resource": resource,
-				"type":     typ,
-			}
-
-			acc.AssertContainsTaggedFields(t, "pressure", pressureFields[typ], tags)
-			acc.AssertContainsTaggedFields(t, "pressure", pressureTotalFields[typ], tags)
-		}
-	}
+	var acc testutil.Accumulator
+	require.NoError(t, k.gatherPressure(&acc))
 
-	// The combination "resource=cpu,type=full" should NOT appear anywhere
-	forbiddenTags := map[string]string{
-		"resource": "cpu",
-		"type":     "full",
+	expected := []telegraf.Metric{
+		metric.New(
+			"pressure",
+			map[string]string{
+				"resource": "cpu",
+				"type":     "some",
+			},
+			map[string]interface{}{
+				"avg10":  float64(10),
+				"avg60":  float64(60),
+				"avg300": float64(300),
+			},
+			time.Unix(0,0),
+			telegraf.Gauge,
+		),
+		metric.New(
+			"pressure",
+			map[string]string{
+				"resource": "cpu",
+				"type":     "some",
+			},
+			map[string]interface{}{
+				"total": uint64(114514),
+			},
+			time.Unix(0,0),
+			telegraf.Counter,
+		),
+		metric.New(
+			"pressure",
+			map[string]string{
+				"resource": "memory",
+				"type":     "some",
+			},
+			map[string]interface{}{
+				"avg10":  float64(10),
+				"avg60":  float64(60),
+				"avg300": float64(300),
+			},
+			time.Unix(0,0),
+			telegraf.Gauge,
+		),
+		metric.New(
+			"pressure",
+			map[string]string{
+				"resource": "memory",
+				"type":     "some",
+			},
+			map[string]interface{}{
+				"total": uint64(114514),
+			},
+			time.Unix(0,0),
+			telegraf.Counter,
+		),
+		metric.New(
+			"pressure",
+			map[string]string{
+				"resource": "io",
+				"type":     "some",
+			},
+			map[string]interface{}{
+				"avg10":  float64(10),
+				"avg60":  float64(60),
+				"avg300": float64(300),
+			},
+			time.Unix(0,0),
+			telegraf.Gauge,
+		),
+		metric.New(
+			"pressure",
+			map[string]string{
+				"resource": "io",
+				"type":     "some",
+			},
+			map[string]interface{}{
+				"total": uint64(114514),
+			},
+			time.Unix(0,0),
+			telegraf.Counter,
+		),
+		metric.New(
+			"pressure",
+			map[string]string{
+				"resource": "memory",
+				"type":     "full",
+			},
+			map[string]interface{}{
+				"avg10":  float64(1),
+				"avg60":  float64(6),
+				"avg300": float64(30),
+			},
+			time.Unix(0,0),
+			telegraf.Gauge,
+		),
+		metric.New(
+			"pressure",
+			map[string]string{
+				"resource": "memory",
+				"type":     "full",
+			},
+			map[string]interface{}{
+				"total": uint64(11451),
+			},
+			time.Unix(0,0),
+			telegraf.Counter,
+		),
+		metric.New(
+			"pressure",
+			map[string]string{
+				"resource": "io",
+				"type":     "full",
+			},
+			map[string]interface{}{
+				"avg10":  float64(1),
+				"avg60":  float64(6),
+				"avg300": float64(30),
+			},
+			time.Unix(0,0),
+			telegraf.Gauge,
+		),
+		metric.New(
+			"pressure",
+			map[string]string{
+				"resource": "io",
+				"type":     "full",
+			},
+			map[string]interface{}{
+				"total": uint64(11451),
+			},
+			time.Unix(0,0),
+			telegraf.Counter,
+		),
 	}
-	acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureFields["full"], forbiddenTags)
-	acc.AssertDoesNotContainsTaggedFields(t, "pressure", pressureTotalFields["full"], forbiddenTags)
+	
+	actual := acc.GetTelegrafMetrics()
+	testutil.RequireMeticsEqual(t, expected, actual, testutil.IgnoreTime(), testutil.SortMetrics())
 }

From 56dd9b2f498c2a10cddc39680b48b5faa1d78d3b Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Fri, 5 Jan 2024 18:55:13 +0800
Subject: [PATCH 25/26] Format with goimports -local

---
 plugins/inputs/kernel/kernel.go   |  2 +-
 plugins/inputs/kernel/psi.go      |  3 ++-
 plugins/inputs/kernel/psi_test.go | 30 +++++++++++++++++-------------
 3 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/plugins/inputs/kernel/kernel.go b/plugins/inputs/kernel/kernel.go
index b63f7e2fa6592..7e79c4936487e 100644
--- a/plugins/inputs/kernel/kernel.go
+++ b/plugins/inputs/kernel/kernel.go
@@ -12,7 +12,7 @@ import (
 	"strconv"
 
 	"github.com/prometheus/procfs"
-	
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs"
 )
diff --git a/plugins/inputs/kernel/psi.go b/plugins/inputs/kernel/psi.go
index 28d54ac3b62a0..c85e2cafec472 100644
--- a/plugins/inputs/kernel/psi.go
+++ b/plugins/inputs/kernel/psi.go
@@ -6,8 +6,9 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/influxdata/telegraf"
 	"github.com/prometheus/procfs"
+
+	"github.com/influxdata/telegraf"
 )
 
 // Gather PSI metrics
diff --git a/plugins/inputs/kernel/psi_test.go b/plugins/inputs/kernel/psi_test.go
index 0228b20b3accc..6552dfe98d587 100644
--- a/plugins/inputs/kernel/psi_test.go
+++ b/plugins/inputs/kernel/psi_test.go
@@ -4,9 +4,13 @@ package kernel
 
 import (
 	"testing"
+	"time"
 
-	"github.com/influxdata/telegraf/testutil"
 	"github.com/stretchr/testify/require"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/metric"
+	"github.com/influxdata/telegraf/testutil"
 )
 
 func TestPSIEnabledWrongDir(t *testing.T) {
@@ -40,7 +44,7 @@ func TestPSIStats(t *testing.T) {
 				"avg60":  float64(60),
 				"avg300": float64(300),
 			},
-			time.Unix(0,0),
+			time.Unix(0, 0),
 			telegraf.Gauge,
 		),
 		metric.New(
@@ -52,7 +56,7 @@ func TestPSIStats(t *testing.T) {
 			map[string]interface{}{
 				"total": uint64(114514),
 			},
-			time.Unix(0,0),
+			time.Unix(0, 0),
 			telegraf.Counter,
 		),
 		metric.New(
@@ -66,7 +70,7 @@ func TestPSIStats(t *testing.T) {
 				"avg60":  float64(60),
 				"avg300": float64(300),
 			},
-			time.Unix(0,0),
+			time.Unix(0, 0),
 			telegraf.Gauge,
 		),
 		metric.New(
@@ -78,7 +82,7 @@ func TestPSIStats(t *testing.T) {
 			map[string]interface{}{
 				"total": uint64(114514),
 			},
-			time.Unix(0,0),
+			time.Unix(0, 0),
 			telegraf.Counter,
 		),
 		metric.New(
@@ -92,7 +96,7 @@ func TestPSIStats(t *testing.T) {
 				"avg60":  float64(60),
 				"avg300": float64(300),
 			},
-			time.Unix(0,0),
+			time.Unix(0, 0),
 			telegraf.Gauge,
 		),
 		metric.New(
@@ -104,7 +108,7 @@ func TestPSIStats(t *testing.T) {
 			map[string]interface{}{
 				"total": uint64(114514),
 			},
-			time.Unix(0,0),
+			time.Unix(0, 0),
 			telegraf.Counter,
 		),
 		metric.New(
@@ -118,7 +122,7 @@ func TestPSIStats(t *testing.T) {
 				"avg60":  float64(6),
 				"avg300": float64(30),
 			},
-			time.Unix(0,0),
+			time.Unix(0, 0),
 			telegraf.Gauge,
 		),
 		metric.New(
@@ -130,7 +134,7 @@ func TestPSIStats(t *testing.T) {
 			map[string]interface{}{
 				"total": uint64(11451),
 			},
-			time.Unix(0,0),
+			time.Unix(0, 0),
 			telegraf.Counter,
 		),
 		metric.New(
@@ -144,7 +148,7 @@ func TestPSIStats(t *testing.T) {
 				"avg60":  float64(6),
 				"avg300": float64(30),
 			},
-			time.Unix(0,0),
+			time.Unix(0, 0),
 			telegraf.Gauge,
 		),
 		metric.New(
@@ -156,11 +160,11 @@ func TestPSIStats(t *testing.T) {
 			map[string]interface{}{
 				"total": uint64(11451),
 			},
-			time.Unix(0,0),
+			time.Unix(0, 0),
 			telegraf.Counter,
 		),
 	}
-	
+
 	actual := acc.GetTelegrafMetrics()
-	testutil.RequireMeticsEqual(t, expected, actual, testutil.IgnoreTime(), testutil.SortMetrics())
+	testutil.RequireMetricsEqual(t, expected, actual, testutil.IgnoreTime(), testutil.SortMetrics())
 }

From 4c12350acf5dd25c9ebaf44d1b56e327422a94e0 Mon Sep 17 00:00:00 2001
From: iBug <git@ibugone.com>
Date: Fri, 5 Jan 2024 19:27:03 +0800
Subject: [PATCH 26/26] inputs/kernel/kernel.go: Revert error wrapping on
 k.gatherPressure

---
 plugins/inputs/kernel/kernel.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/inputs/kernel/kernel.go b/plugins/inputs/kernel/kernel.go
index 7e79c4936487e..58e3af0448704 100644
--- a/plugins/inputs/kernel/kernel.go
+++ b/plugins/inputs/kernel/kernel.go
@@ -159,7 +159,7 @@ func (k *Kernel) Gather(acc telegraf.Accumulator) error {
 
 	if k.optCollect["psi"] {
 		if err := k.gatherPressure(acc); err != nil {
-			return fmt.Errorf("gathering pressure failed: %w", err)
+			return err
 		}
 	}