fix(inputs.procstat): Collect swap via /proc/$pid/smaps (#13779)

plugins/inputs/procstat/README.md

@@ -111,10 +111,15 @@ the `win_perf_counters` input plugin as a more mature alternative.
     - cpu_usage (float)
     - involuntary_context_switches (int)
     - major_faults (int)
-    - memory_data (int)
+    - memory_anonymous (int)
-    - memory_locked (int)
+    - memory_private_clean (int)
+    - memory_private_dirty (int)
+    - memory_pss (int)
+    - memory_referenced (int)
     - memory_rss (int)
-    - memory_stack (int)
+    - memory_shared_clean (int)
+    - memory_shared_dirty (int)
+    - memory_size (int)
     - memory_swap (int)
     - memory_usage (float)
     - memory_vms (int)

plugins/inputs/procstat/memmap.go

@@ -0,0 +1,19 @@
+//go:build linux
+
+package procstat
+
+func collectMemmap(proc Process, prefix string, fields map[string]any) {
+	memMapStats, err := proc.MemoryMaps(true)
+	if err == nil && len(*memMapStats) == 1 {
+		memMap := (*memMapStats)[0]
+		fields[prefix+"memory_size"] = memMap.Size
+		fields[prefix+"memory_pss"] = memMap.Pss
+		fields[prefix+"memory_shared_clean"] = memMap.SharedClean
+		fields[prefix+"memory_shared_dirty"] = memMap.SharedDirty
+		fields[prefix+"memory_private_clean"] = memMap.PrivateClean
+		fields[prefix+"memory_private_dirty"] = memMap.PrivateDirty
+		fields[prefix+"memory_referenced"] = memMap.Referenced
+		fields[prefix+"memory_anonymous"] = memMap.Anonymous
+		fields[prefix+"memory_swap"] = memMap.Swap
+	}
+}

plugins/inputs/procstat/memmap_notlinux.go

@@ -0,0 +1,5 @@
+//go:build !linux
+
+package procstat
+
+func collectMemmap(Process, string, map[string]any) {}

plugins/inputs/procstat/process.go

@@ -16,6 +16,7 @@ type Process interface {
 	PageFaults() (*process.PageFaultsStat, error)
 	IOCounters() (*process.IOCountersStat, error)
 	MemoryInfo() (*process.MemoryInfoStat, error)
+	MemoryMaps(bool) (*[]process.MemoryMapsStat, error)
 	Name() (string, error)
 	Cmdline() (string, error)
 	NumCtxSwitches() (*process.NumCtxSwitchesStat, error)

plugins/inputs/procstat/procstat.go

@@ -225,16 +225,15 @@ func (p *Procstat) addMetric(proc Process, acc telegraf.Accumulator, t time.Time
 		}
 	}
 
+	// This only returns values for RSS and VMS
 	mem, err := proc.MemoryInfo()
 	if err == nil {
 		fields[prefix+"memory_rss"] = mem.RSS
 		fields[prefix+"memory_vms"] = mem.VMS
-		fields[prefix+"memory_swap"] = mem.Swap
-		fields[prefix+"memory_data"] = mem.Data
-		fields[prefix+"memory_stack"] = mem.Stack
-		fields[prefix+"memory_locked"] = mem.Locked
 	}
 
+	collectMemmap(proc, prefix, fields)
+
 	memPerc, err := proc.MemoryPercent()
 	if err == nil {
 		fields[prefix+"memory_usage"] = memPerc

plugins/inputs/procstat/procstat_test.go

@@ -129,6 +129,10 @@ func (p *testProc) MemoryInfo() (*process.MemoryInfoStat, error) {
 	return &process.MemoryInfoStat{}, nil
 }
 
+func (p *testProc) MemoryMaps(bool) (*[]process.MemoryMapsStat, error) {
+	return &[]process.MemoryMapsStat{}, nil
+}
+
 func (p *testProc) Name() (string, error) {
 	return "test_proc", nil
 }