Fix bug:getTopology will be failed on Arm platform

machine/machine.go

@@ -16,12 +16,13 @@
 package machine
 
 import (
+	"bytes"
 	"fmt"
 	"io/ioutil"
+	"path/filepath"
 	"regexp"
 	"strconv"
 	"strings"
-
 	// s390/s390x changes
 	"runtime"
 
@@ -36,16 +37,18 @@ import (
 )
 
 var (
-	cpuRegExp  = regexp.MustCompile(`^processor\s*:\s*([0-9]+)$`)
-	coreRegExp = regexp.MustCompile(`^core id\s*:\s*([0-9]+)$`)
-	nodeRegExp = regexp.MustCompile(`^physical id\s*:\s*([0-9]+)$`)
+	cpuRegExp     = regexp.MustCompile(`^processor\s*:\s*([0-9]+)$`)
+	coreRegExp    = regexp.MustCompile(`^core id\s*:\s*([0-9]+)$`)
+	nodeRegExp    = regexp.MustCompile(`^physical id\s*:\s*([0-9]+)$`)
+	nodeBusRegExp = regexp.MustCompile(`^node([0-9]+)$`)
 	// Power systems have a different format so cater for both
 	cpuClockSpeedMHz     = regexp.MustCompile(`(?:cpu MHz|clock)\s*:\s*([0-9]+\.[0-9]+)(?:MHz)?`)
 	memoryCapacityRegexp = regexp.MustCompile(`MemTotal:\s*([0-9]+) kB`)
 	swapCapacityRegexp   = regexp.MustCompile(`SwapTotal:\s*([0-9]+) kB`)
 )
 
 const maxFreqFile = "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq"
+const cpuBusPath = "/sys/bus/cpu/devices/"
 
 // GetClockSpeed returns the CPU clock speed, given a []byte formatted as the /proc/cpuinfo file.
 func GetClockSpeed(procInfo []byte) (uint64, error) {
@@ -127,6 +130,67 @@ func parseCapacity(b []byte, r *regexp.Regexp) (uint64, error) {
 	return m * 1024, err
 }
 
+/* look for sysfs cpu path containing core_id */
+/* such as: sys/bus/cpu/devices/cpu0/topology/core_id */
+func getCoreIdFromCpuBus(cpuBusPath string, threadId int) (int, error) {
+	path := filepath.Join(cpuBusPath, fmt.Sprintf("cpu%d/topology", threadId))
+	file := filepath.Join(path, "core_id")
+
+	num, err := ioutil.ReadFile(file)
+	if err != nil {
+		return threadId, err
+	}
+
+	coreId, err := strconv.ParseInt(string(bytes.TrimSpace(num)), 10, 32)
+	if err != nil {
+		return threadId, err
+	}
+
+	if coreId < 0 {
+		// report threadId if found coreId < 0
+		coreId = int64(threadId)
+	}
+
+	return int(coreId), nil
+}
+
+/* look for sysfs cpu path containing node id */
+/* such as: /sys/bus/cpu/devices/cpu0/node%d */
+func getNodeIdFromCpuBus(cpuBusPath string, threadId int) (int, error) {
+	path := filepath.Join(cpuBusPath, fmt.Sprintf("cpu%d", threadId))
+
+	files, err := ioutil.ReadDir(path)
+	if err != nil {
+		return 0, err
+	}
+
+	nodeId := 0
+	for _, file := range files {
+		filename := file.Name()
+
+		isNode, error := regexp.MatchString("^node([0-9]+)$", filename)
+		if error != nil {
+			continue
+		}
+		if !isNode {
+			continue
+		}
+
+		ok, val, _ := extractValue(filename, nodeBusRegExp)
+		if err != nil {
+			continue
+		}
+		if ok {
+			if val < 0 {
+				continue
+			}
+			nodeId = val
+		}
+	}
+
+	return nodeId, nil
+}
+
 func GetTopology(sysFs sysfs.SysFs, cpuinfo string) ([]info.Node, int, error) {
 	nodes := []info.Node{}
 
@@ -161,8 +225,34 @@ func GetTopology(sysFs sysfs.SysFs, cpuinfo string) ([]info.Node, int, error) {
 				lastNode = -1
 			}
 			lastThread = thread
+
+			/* On Arm platform, no 'core id' and 'physical id' in '/proc/cpuinfo'. */
+			/* So we search sysfs cpu path directly. */
+			/* This method can also be used on other platforms, such as x86, ppc64le... */
+			/* /sys/bus/cpu/devices/cpu%d contains the information of 'core_id' & 'node_id'. */
+			/* Such as: /sys/bus/cpu/devices/cpu0/topology/core_id */
+			/* Such as:  /sys/bus/cpu/devices/cpu0/node0 */
+			if isAArch64() {
+				val, err = getCoreIdFromCpuBus(cpuBusPath, lastThread)
+				if err != nil {
+					return nil, -1, fmt.Errorf("could not parse core info from %q: %v", cpuBusPath, err)
+				}
+				lastCore = val
+
+				val, err = getNodeIdFromCpuBus(cpuBusPath, lastThread)
+				if err != nil {
+					return nil, -1, fmt.Errorf("could not parse node info from %q: %v", cpuBusPath, err)
+				}
+				lastNode = val
+			}
 			continue
 		}
+
+		if isAArch64() {
+			/* On Arm platform, no 'core id' and 'physical id' in '/proc/cpuinfo'. */
+			continue
+		}
+
 		ok, val, err = extractValue(line, coreRegExp)
 		if err != nil {
 			return nil, -1, fmt.Errorf("could not parse core info from %q: %v", line, err)
@@ -171,6 +261,7 @@ func GetTopology(sysFs sysfs.SysFs, cpuinfo string) ([]info.Node, int, error) {
 			lastCore = val
 			continue
 		}
+
 		ok, val, err = extractValue(line, nodeRegExp)
 		if err != nil {
 			return nil, -1, fmt.Errorf("could not parse node info from %q: %v", line, err)
@@ -180,6 +271,7 @@ func GetTopology(sysFs sysfs.SysFs, cpuinfo string) ([]info.Node, int, error) {
 			continue
 		}
 	}
+
 	nodeIdx, err := addNode(&nodes, lastNode)
 	if err != nil {
 		return nil, -1, fmt.Errorf("failed to add node %d: %v", lastNode, err)

machine/testdata/cpu0/topology/core_id

@@ -0,0 +1 @@
+0

machine/testdata/cpu9999/topology/core_id

@@ -0,0 +1 @@
+8888

machine/topology_test.go

@@ -115,3 +115,27 @@ func TestTopologyEmptyCpuinfo(t *testing.T) {
 		t.Errorf("Expected empty cpuinfo to fail.")
 	}
 }
+
+func TestTopologyCoreId(t *testing.T) {
+	val, _ := getCoreIdFromCpuBus("./testdata", 0)
+	if val != 0 {
+		t.Errorf("Expected core 0, found %d", val)
+	}
+
+	val, _ = getCoreIdFromCpuBus("./testdata", 9999)
+	if val != 8888 {
+		t.Errorf("Expected core 8888, found %d", val)
+	}
+}
+
+func TestTopologyNodeId(t *testing.T) {
+	val, _ := getNodeIdFromCpuBus("./testdata", 0)
+	if val != 0 {
+		t.Errorf("Expected core 0, found %d", val)
+	}
+
+	val, _ = getNodeIdFromCpuBus("./testdata", 9999)
+	if val != 1234 {
+		t.Errorf("Expected core 1234 , found %d", val)
+	}
+}