From d138b59aa23df198584e56535f60e0b2047ff76a Mon Sep 17 00:00:00 2001
From: "sewon.oh" <sewon.oh@samsung.com>
Date: Tue, 3 Sep 2019 13:49:23 +0900
Subject: [PATCH] Add hugepage info to v1 node structure

Signed-off-by: sewon.oh <sewon.oh@samsung.com>
---
 info/v1/machine.go       |  7 +++---
 machine/machine.go       | 49 ++++++++++++++++++++++++++++++++++++++++
 machine/topology_test.go |  4 ++++
 3 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/info/v1/machine.go b/info/v1/machine.go
index cf5e828d..cb25501c 100644
--- a/info/v1/machine.go
+++ b/info/v1/machine.go
@@ -38,9 +38,10 @@ type FsInfo struct {
 type Node struct {
 	Id int `json:"node_id"`
 	// Per-node memory
-	Memory uint64  `json:"memory"`
-	Cores  []Core  `json:"cores"`
-	Caches []Cache `json:"caches"`
+	Memory    uint64          `json:"memory"`
+	HugePages []HugePagesInfo `json:"huge_pages"`
+	Cores     []Core          `json:"cores"`
+	Caches    []Cache         `json:"caches"`
 }
 
 type Core struct {
diff --git a/machine/machine.go b/machine/machine.go
index d85e38f1..f1aad5e8 100644
--- a/machine/machine.go
+++ b/machine/machine.go
@@ -23,6 +23,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+
 	// s390/s390x changes
 	"runtime"
 
@@ -45,10 +46,12 @@ var (
 	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`)
+	hugePageSizeRegexp   = regexp.MustCompile(`hugepages-\s*([0-9]+)kB`)
 )
 
 const maxFreqFile = "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq"
 const cpuBusPath = "/sys/bus/cpu/devices/"
+const nodePath = "/sys/devices/system/node"
 
 // GetClockSpeed returns the CPU clock speed, given a []byte formatted as the /proc/cpuinfo file.
 func GetClockSpeed(procInfo []byte) (uint64, error) {
@@ -191,6 +194,45 @@ func getNodeIdFromCpuBus(cpuBusPath string, threadId int) (int, error) {
 	return nodeId, nil
 }
 
+/* Look for per-node hugepages info using node id */
+/* Such as: /sys/devices/system/node/node%d/hugepages */
+func getHugePagesInfoFromNode(nodePath string, nodeIndex int) ([]info.HugePagesInfo, error) {
+	hugePagesInfo := []info.HugePagesInfo{}
+	path := filepath.Join(nodePath, fmt.Sprintf("node%d/hugepages", nodeIndex))
+	files, err := ioutil.ReadDir(path)
+	// Ignore if per-node info is not available.
+	if err != nil {
+		klog.Errorf("failed to get hugepages information for node %d: %v", nodeIndex, err)
+		return nil, nil
+	}
+
+	for _, file := range files {
+		fileName := file.Name()
+		pageSize, err := parseCapacity([]byte(fileName), hugePageSizeRegexp)
+		if err != nil {
+			return nil, err
+		}
+
+		file := filepath.Join(path, fileName, "nr_hugepages")
+		num, err := ioutil.ReadFile(file)
+		if err != nil {
+			return nil, err
+		}
+
+		pageNum, err := strconv.ParseUint(string(bytes.TrimSpace(num)), 10, 64)
+		if err != nil {
+			return nil, err
+		}
+
+		hugePagesInfo = append(hugePagesInfo, info.HugePagesInfo{
+			PageSize: pageSize / 1024, // Convert to kB.
+			NumPages: pageNum,
+		})
+	}
+
+	return hugePagesInfo, nil
+}
+
 func GetTopology(sysFs sysfs.SysFs, cpuinfo string) ([]info.Node, int, error) {
 	nodes := []info.Node{}
 
@@ -305,6 +347,13 @@ func GetTopology(sysFs sysfs.SysFs, cpuinfo string) ([]info.Node, int, error) {
 			}
 			// Ignore unknown caches.
 		}
+
+		// Add a node-level huge pages info.
+		hugePagesInfo, err := getHugePagesInfoFromNode(nodePath, node.Id)
+		if err != nil {
+			return nil, -1, err
+		}
+		nodes[idx].HugePages = hugePagesInfo
 	}
 	return nodes, numCores, nil
 }
diff --git a/machine/topology_test.go b/machine/topology_test.go
index ca25ef7d..5144daf0 100644
--- a/machine/topology_test.go
+++ b/machine/topology_test.go
@@ -59,6 +59,8 @@ func TestTopology(t *testing.T) {
 		node := info.Node{Id: i}
 		// Copy over Memory from result. TODO(rjnagal): Use memory from fake.
 		node.Memory = topology[i].Memory
+		// Copy over HugePagesInfo from result. TODO(ohsewon): Use HugePagesInfo from fake.
+		node.HugePages = topology[i].HugePages
 		for j := 0; j < numCoresPerNode; j++ {
 			core := info.Core{Id: i*numCoresPerNode + j}
 			core.Caches = append(core.Caches, cache)
@@ -100,6 +102,8 @@ func TestTopologyWithSimpleCpuinfo(t *testing.T) {
 	node.Cores = append(node.Cores, core)
 	// Copy over Memory from result. TODO(rjnagal): Use memory from fake.
 	node.Memory = topology[0].Memory
+	// Copy over HugePagesInfo from result. TODO(ohsewon): Use HugePagesInfo from fake.
+	node.HugePages = topology[0].HugePages
 	expected := []info.Node{node}
 	if !reflect.DeepEqual(topology, expected) {
 		t.Errorf("Expected topology %+v, got %+v", expected, topology)