fix(meminfo): account for optional unit field so values are accurate

meminfo.go

@@ -140,6 +140,54 @@ type Meminfo struct {
 	DirectMap4k       *uint64
 	DirectMap2M       *uint64
 	DirectMap1G       *uint64
+
+	// The struct fields below are the byte-normalized counterparts to the
+	// existing struct fields. Values are normalized using the optional
+	// unit field in the meminfo line.
+	MemTotalBytes          *uint64
+	MemFreeBytes           *uint64
+	MemAvailableBytes      *uint64
+	BuffersBytes           *uint64
+	CachedBytes            *uint64
+	SwapCachedBytes        *uint64
+	ActiveBytes            *uint64
+	InactiveBytes          *uint64
+	ActiveAnonBytes        *uint64
+	InactiveAnonBytes      *uint64
+	ActiveFileBytes        *uint64
+	InactiveFileBytes      *uint64
+	UnevictableBytes       *uint64
+	MlockedBytes           *uint64
+	SwapTotalBytes         *uint64
+	SwapFreeBytes          *uint64
+	DirtyBytes             *uint64
+	WritebackBytes         *uint64
+	AnonPagesBytes         *uint64
+	MappedBytes            *uint64
+	ShmemBytes             *uint64
+	SlabBytes              *uint64
+	SReclaimableBytes      *uint64
+	SUnreclaimBytes        *uint64
+	KernelStackBytes       *uint64
+	PageTablesBytes        *uint64
+	NFSUnstableBytes       *uint64
+	BounceBytes            *uint64
+	WritebackTmpBytes      *uint64
+	CommitLimitBytes       *uint64
+	CommittedASBytes       *uint64
+	VmallocTotalBytes      *uint64
+	VmallocUsedBytes       *uint64
+	VmallocChunkBytes      *uint64
+	HardwareCorruptedBytes *uint64
+	AnonHugePagesBytes     *uint64
+	ShmemHugePagesBytes    *uint64
+	ShmemPmdMappedBytes    *uint64
+	CmaTotalBytes          *uint64
+	CmaFreeBytes           *uint64
+	HugepagesizeBytes      *uint64
+	DirectMap4kBytes       *uint64
+	DirectMap2MBytes       *uint64
+	DirectMap1GBytes       *uint64
 }
 
 // Meminfo returns an information about current kernel/system memory statistics.
@@ -162,114 +210,173 @@ func parseMemInfo(r io.Reader) (*Meminfo, error) {
 	var m Meminfo
 	s := bufio.NewScanner(r)
 	for s.Scan() {
-		// Each line has at least a name and value; we ignore the unit.
 		fields := strings.Fields(s.Text())
-		if len(fields) < 2 {
-			return nil, fmt.Errorf("%w: Malformed line %q", ErrFileParse, s.Text())
-		}
+		var val, valBytes uint64
 
-		v, err := strconv.ParseUint(fields[1], 0, 64)
+		val, err := strconv.ParseUint(fields[1], 0, 64)
 		if err != nil {
 			return nil, err
 		}
 
+		switch len(fields) {
+		case 2:
+			// No unit present, use the parsed the value as bytes directly.
+			valBytes = val
+		case 3:
+			// Unit present in optional 3rd field, convert it to
+			// bytes. The only unit supported within the Linux
+			// kernel is `kB`.
+			if fields[2] != "kB" {
+				return nil, fmt.Errorf("%w: Unsupported unit in optional 3rd field %q", ErrFileParse, fields[2])
+			}
+
+			valBytes = 1024 * val
+
+		default:
+			return nil, fmt.Errorf("%w: Malformed line %q", ErrFileParse, s.Text())
+		}
+
 		switch fields[0] {
 		case "MemTotal:":
-			m.MemTotal = &v
+			m.MemTotal = &val
+			m.MemTotalBytes = &valBytes
 		case "MemFree:":
-			m.MemFree = &v
+			m.MemFree = &val
+			m.MemFreeBytes = &valBytes
 		case "MemAvailable:":
-			m.MemAvailable = &v
+			m.MemAvailable = &val
+			m.MemAvailableBytes = &valBytes
 		case "Buffers:":
-			m.Buffers = &v
+			m.Buffers = &val
+			m.BuffersBytes = &valBytes
 		case "Cached:":
-			m.Cached = &v
+			m.Cached = &val
+			m.CachedBytes = &valBytes
 		case "SwapCached:":
-			m.SwapCached = &v
+			m.SwapCached = &val
+			m.SwapCachedBytes = &valBytes
 		case "Active:":
-			m.Active = &v
+			m.Active = &val
+			m.ActiveBytes = &valBytes
 		case "Inactive:":
-			m.Inactive = &v
+			m.Inactive = &val
+			m.InactiveBytes = &valBytes
 		case "Active(anon):":
-			m.ActiveAnon = &v
+			m.ActiveAnon = &val
+			m.ActiveAnonBytes = &valBytes
 		case "Inactive(anon):":
-			m.InactiveAnon = &v
+			m.InactiveAnon = &val
+			m.InactiveAnonBytes = &valBytes
 		case "Active(file):":
-			m.ActiveFile = &v
+			m.ActiveFile = &val
+			m.ActiveFileBytes = &valBytes
 		case "Inactive(file):":
-			m.InactiveFile = &v
+			m.InactiveFile = &val
+			m.InactiveFileBytes = &valBytes
 		case "Unevictable:":
-			m.Unevictable = &v
+			m.Unevictable = &val
+			m.UnevictableBytes = &valBytes
 		case "Mlocked:":
-			m.Mlocked = &v
+			m.Mlocked = &val
+			m.MlockedBytes = &valBytes
 		case "SwapTotal:":
-			m.SwapTotal = &v
+			m.SwapTotal = &val
+			m.SwapTotalBytes = &valBytes
 		case "SwapFree:":
-			m.SwapFree = &v
+			m.SwapFree = &val
+			m.SwapFreeBytes = &valBytes
 		case "Dirty:":
-			m.Dirty = &v
+			m.Dirty = &val
+			m.DirtyBytes = &valBytes
 		case "Writeback:":
-			m.Writeback = &v
+			m.Writeback = &val
+			m.WritebackBytes = &valBytes
 		case "AnonPages:":
-			m.AnonPages = &v
+			m.AnonPages = &val
+			m.AnonPagesBytes = &valBytes
 		case "Mapped:":
-			m.Mapped = &v
+			m.Mapped = &val
+			m.MappedBytes = &valBytes
 		case "Shmem:":
-			m.Shmem = &v
+			m.Shmem = &val
+			m.ShmemBytes = &valBytes
 		case "Slab:":
-			m.Slab = &v
+			m.Slab = &val
+			m.SlabBytes = &valBytes
 		case "SReclaimable:":
-			m.SReclaimable = &v
+			m.SReclaimable = &val
+			m.SReclaimableBytes = &valBytes
 		case "SUnreclaim:":
-			m.SUnreclaim = &v
+			m.SUnreclaim = &val
+			m.SUnreclaimBytes = &valBytes
 		case "KernelStack:":
-			m.KernelStack = &v
+			m.KernelStack = &val
+			m.KernelStackBytes = &valBytes
 		case "PageTables:":
-			m.PageTables = &v
+			m.PageTables = &val
+			m.PageTablesBytes = &valBytes
 		case "NFS_Unstable:":
-			m.NFSUnstable = &v
+			m.NFSUnstable = &val
+			m.NFSUnstableBytes = &valBytes
 		case "Bounce:":
-			m.Bounce = &v
+			m.Bounce = &val
+			m.BounceBytes = &valBytes
 		case "WritebackTmp:":
-			m.WritebackTmp = &v
+			m.WritebackTmp = &val
+			m.WritebackTmpBytes = &valBytes
 		case "CommitLimit:":
-			m.CommitLimit = &v
+			m.CommitLimit = &val
+			m.CommitLimitBytes = &valBytes
 		case "Committed_AS:":
-			m.CommittedAS = &v
+			m.CommittedAS = &val
+			m.CommittedASBytes = &valBytes
 		case "VmallocTotal:":
-			m.VmallocTotal = &v
+			m.VmallocTotal = &val
+			m.VmallocTotalBytes = &valBytes
 		case "VmallocUsed:":
-			m.VmallocUsed = &v
+			m.VmallocUsed = &val
+			m.VmallocUsedBytes = &valBytes
 		case "VmallocChunk:":
-			m.VmallocChunk = &v
+			m.VmallocChunk = &val
+			m.VmallocChunkBytes = &valBytes
 		case "HardwareCorrupted:":
-			m.HardwareCorrupted = &v
+			m.HardwareCorrupted = &val
+			m.HardwareCorruptedBytes = &valBytes
 		case "AnonHugePages:":
-			m.AnonHugePages = &v
+			m.AnonHugePages = &val
+			m.AnonHugePagesBytes = &valBytes
 		case "ShmemHugePages:":
-			m.ShmemHugePages = &v
+			m.ShmemHugePages = &val
+			m.ShmemHugePagesBytes = &valBytes
 		case "ShmemPmdMapped:":
-			m.ShmemPmdMapped = &v
+			m.ShmemPmdMapped = &val
+			m.ShmemPmdMappedBytes = &valBytes
 		case "CmaTotal:":
-			m.CmaTotal = &v
+			m.CmaTotal = &val
+			m.CmaTotalBytes = &valBytes
 		case "CmaFree:":
-			m.CmaFree = &v
+			m.CmaFree = &val
+			m.CmaFreeBytes = &valBytes
 		case "HugePages_Total:":
-			m.HugePagesTotal = &v
+			m.HugePagesTotal = &val
 		case "HugePages_Free:":
-			m.HugePagesFree = &v
+			m.HugePagesFree = &val
 		case "HugePages_Rsvd:":
-			m.HugePagesRsvd = &v
+			m.HugePagesRsvd = &val
 		case "HugePages_Surp:":
-			m.HugePagesSurp = &v
+			m.HugePagesSurp = &val
 		case "Hugepagesize:":
-			m.Hugepagesize = &v
+			m.Hugepagesize = &val
+			m.HugepagesizeBytes = &valBytes
 		case "DirectMap4k:":
-			m.DirectMap4k = &v
+			m.DirectMap4k = &val
+			m.DirectMap4kBytes = &valBytes
 		case "DirectMap2M:":
-			m.DirectMap2M = &v
+			m.DirectMap2M = &val
+			m.DirectMap2MBytes = &valBytes
 		case "DirectMap1G:":
-			m.DirectMap1G = &v
+			m.DirectMap1G = &val
+			m.DirectMap1GBytes = &valBytes
 		}
 	}
 

meminfo_test.go

@@ -62,6 +62,45 @@ func TestMeminfo(t *testing.T) {
 		Hugepagesize:      newuint64(2048),
 		DirectMap4k:       newuint64(91136),
 		DirectMap2M:       newuint64(16039936),
+
+		MemTotalBytes:          newuint64(16042172416),
+		MemFreeBytes:           newuint64(450891776),
+		BuffersBytes:           newuint64(1044611072),
+		CachedBytes:            newuint64(12295823360),
+		SwapCachedBytes:        newuint64(0),
+		ActiveBytes:            newuint64(6923546624),
+		InactiveBytes:          newuint64(6689492992),
+		ActiveAnonBytes:        newuint64(273670144),
+		InactiveAnonBytes:      newuint64(274432),
+		ActiveFileBytes:        newuint64(6649876480),
+		InactiveFileBytes:      newuint64(6689218560),
+		UnevictableBytes:       newuint64(0),
+		MlockedBytes:           newuint64(0),
+		SwapTotalBytes:         newuint64(0),
+		SwapFreeBytes:          newuint64(0),
+		DirtyBytes:             newuint64(786432),
+		WritebackBytes:         newuint64(0),
+		AnonPagesBytes:         newuint64(272605184),
+		MappedBytes:            newuint64(45264896),
+		ShmemBytes:             newuint64(1339392),
+		SlabBytes:              newuint64(1850638336),
+		SReclaimableBytes:      newuint64(1779838976),
+		SUnreclaimBytes:        newuint64(70799360),
+		KernelStackBytes:       newuint64(1654784),
+		PageTablesBytes:        newuint64(5414912),
+		NFSUnstableBytes:       newuint64(0),
+		BounceBytes:            newuint64(0),
+		WritebackTmpBytes:      newuint64(0),
+		CommitLimitBytes:       newuint64(8021086208),
+		CommittedASBytes:       newuint64(543584256),
+		VmallocTotalBytes:      newuint64(35184372087808),
+		VmallocUsedBytes:       newuint64(37474304),
+		VmallocChunkBytes:      newuint64(35184269148160),
+		HardwareCorruptedBytes: newuint64(0),
+		AnonHugePagesBytes:     newuint64(12582912),
+		HugepagesizeBytes:      newuint64(2097152),
+		DirectMap4kBytes:       newuint64(93323264),
+		DirectMap2MBytes:       newuint64(16424894464),
 	}
 
 	have, err := getProcFixtures(t).Meminfo()