libct/cg/fs2: Fix statHugeTlb error when rsvd usage is present

Signed-off-by: Gavin Lam <[email protected]>

Author: gavinkflam

fs2/hugetlb.go

@@ -45,8 +45,8 @@ func statHugeTlb(dirPath string, stats *cgroups.Stats) error {
 	rsvd := ".rsvd"
 	for _, pagesize := range cgroups.HugePageSizes() {
 	again:
-		prefix := "hugetlb." + pagesize + rsvd
-		value, err := fscommon.GetCgroupParamUint(dirPath, prefix+".current")
+		prefix := "hugetlb." + pagesize
+		value, err := fscommon.GetCgroupParamUint(dirPath, prefix+rsvd+".current")
 		if err != nil {
 			if rsvd != "" && errors.Is(err, os.ErrNotExist) {
 				rsvd = ""

fs2/hugetlb_test.go

@@ -0,0 +1,139 @@
+package fs2
+
+import (
+	"fmt"
+	"strconv"
+	"testing"
+
+	"github.com/opencontainers/cgroups"
+	"github.com/opencontainers/cgroups/fscommon"
+)
+
+const (
+	hugetlbUsageContents = "128"
+	hugetlbFailcnt       = "max 100"
+)
+
+const (
+	usage   = "hugetlb.%s.current"
+	limit   = "hugetlb.%s.max"
+	failcnt = "hugetlb.%s.events"
+
+	rsvdUsage = "hugetlb.%s.rsvd.current"
+	rsvdLimit = "hugetlb.%s.rsvd.max"
+)
+
+func TestSetHugetlb(t *testing.T) {
+	path := t.TempDir()
+
+	const (
+		hugetlbBefore = 256
+		hugetlbAfter  = 512
+	)
+
+	for _, pageSize := range cgroups.HugePageSizes() {
+		writeFileContents(t, path, map[string]string{
+			fmt.Sprintf(limit, pageSize): strconv.Itoa(hugetlbBefore),
+		})
+	}
+
+	r := &cgroups.Resources{}
+	for _, pageSize := range cgroups.HugePageSizes() {
+		r.HugetlbLimit = []*cgroups.HugepageLimit{
+			{
+				Pagesize: pageSize,
+				Limit:    hugetlbAfter,
+			},
+		}
+		if err := setHugeTlb(path, r); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	for _, pageSize := range cgroups.HugePageSizes() {
+		for _, f := range []string{limit, rsvdLimit} {
+			limit := fmt.Sprintf(f, pageSize)
+			value, err := fscommon.GetCgroupParamUint(path, limit)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if value != hugetlbAfter {
+				t.Fatalf("Set %s failed. Expected: %v, Got: %v", limit, hugetlbAfter, value)
+			}
+		}
+	}
+}
+
+func TestStatHugetlb(t *testing.T) {
+	path := t.TempDir()
+	for _, pageSize := range cgroups.HugePageSizes() {
+		writeFileContents(t, path, map[string]string{
+			fmt.Sprintf(rsvdUsage, pageSize): hugetlbUsageContents,
+			fmt.Sprintf(failcnt, pageSize):   hugetlbFailcnt,
+		})
+	}
+
+	actualStats := *cgroups.NewStats()
+	err := statHugeTlb(path, &actualStats)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expectedStats := cgroups.HugetlbStats{Usage: 128, Failcnt: 100}
+	for _, pageSize := range cgroups.HugePageSizes() {
+		if expectedStats != actualStats.HugetlbStats[pageSize] {
+			t.Errorf("Expected hugetlb stats: %v, actual: %v", expectedStats, actualStats.HugetlbStats[pageSize])
+		}
+	}
+}
+
+func TestStatHugetlbWithNoRsvdUsage(t *testing.T) {
+	path := t.TempDir()
+	for _, pageSize := range cgroups.HugePageSizes() {
+		writeFileContents(t, path, map[string]string{
+			fmt.Sprintf(usage, pageSize):   hugetlbUsageContents,
+			fmt.Sprintf(failcnt, pageSize): hugetlbFailcnt,
+		})
+	}
+
+	actualStats := *cgroups.NewStats()
+	err := statHugeTlb(path, &actualStats)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expectedStats := cgroups.HugetlbStats{Usage: 128, Failcnt: 100}
+	for _, pageSize := range cgroups.HugePageSizes() {
+		if expectedStats != actualStats.HugetlbStats[pageSize] {
+			t.Errorf("Expected hugetlb stats: %v, actual: %v", expectedStats, actualStats.HugetlbStats[pageSize])
+		}
+	}
+}
+
+func TestStatHugetlbNoUsageFile(t *testing.T) {
+	path := t.TempDir()
+	for _, pageSize := range cgroups.HugePageSizes() {
+		writeFileContents(t, path, map[string]string{
+			fmt.Sprintf(failcnt, pageSize): hugetlbFailcnt,
+		})
+	}
+
+	actualStats := *cgroups.NewStats()
+	err := statHugeTlb(path, &actualStats)
+	if err == nil {
+		t.Fatal("Expected failure")
+	}
+}
+
+func TestStatHugetlbBadUsageFile(t *testing.T) {
+	path := t.TempDir()
+	for _, pageSize := range cgroups.HugePageSizes() {
+		writeFileContents(t, path, map[string]string{
+			fmt.Sprintf(usage, pageSize): "bad",
+		})
+	}
+
+	actualStats := *cgroups.NewStats()
+	err := statHugeTlb(path, &actualStats)
+	if err == nil {
+		t.Fatal("Expected failure")
+	}
+}

fs2/utils_test.go

@@ -0,0 +1,22 @@
+package fs2
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/opencontainers/cgroups"
+)
+
+func init() {
+	cgroups.TestMode = true
+}
+
+func writeFileContents(t testing.TB, path string, fileContents map[string]string) {
+	for file, contents := range fileContents {
+		statPath := filepath.Join(path, file)
+		if err := os.WriteFile(statPath, []byte(contents), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+}