Fix cgroup hugetlb size prefix for kB

libcontainer/cgroups/utils.go

@@ -22,6 +22,13 @@ const (
 	CgroupProcesses  = "cgroup.procs"
 )
 
+// HugePageSizeUnitList is a list of the units used by the linux kernel when
+// naming the HugePage control files.
+// https://www.kernel.org/doc/Documentation/cgroup-v1/hugetlb.txt
+// TODO Since the kernel only use KB, MB and GB; TB and PB should be removed,
+// depends on https://github.com/docker/go-units/commit/a09cd47f892041a4fac473133d181f5aea6fa393
+var HugePageSizeUnitList = []string{"B", "KB", "MB", "GB", "TB", "PB"}
+
 // https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt
 func FindCgroupMountpoint(cgroupPath, subsystem string) (string, error) {
 	mnt, _, err := FindCgroupMountpointAndRoot(cgroupPath, subsystem)
@@ -409,19 +416,26 @@ func RemovePaths(paths map[string]string) (err error) {
 }
 
 func GetHugePageSize() ([]string, error) {
-	var pageSizes []string
-	sizeList := []string{"B", "kB", "MB", "GB", "TB", "PB"}
 	files, err := ioutil.ReadDir("/sys/kernel/mm/hugepages")
 	if err != nil {
-		return pageSizes, err
+		return []string{}, err
 	}
+	var fileNames []string
 	for _, st := range files {
-		nameArray := strings.Split(st.Name(), "-")
+		fileNames = append(fileNames, st.Name())
+	}
+	return getHugePageSizeFromFilenames(fileNames)
+}
+
+func getHugePageSizeFromFilenames(fileNames []string) ([]string, error) {
+	var pageSizes []string
+	for _, fileName := range fileNames {
+		nameArray := strings.Split(fileName, "-")
 		pageSize, err := units.RAMInBytes(nameArray[1])
 		if err != nil {
 			return []string{}, err
 		}
-		sizeString := units.CustomSize("%g%s", float64(pageSize), 1024.0, sizeList)
+		sizeString := units.CustomSize("%g%s", float64(pageSize), 1024.0, HugePageSizeUnitList)
 		pageSizes = append(pageSizes, sizeString)
 	}
 

libcontainer/cgroups/utils_test.go

@@ -4,6 +4,7 @@ package cgroups
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"reflect"
 	"strings"
@@ -421,3 +422,38 @@ func TestFindCgroupMountpointAndRoot(t *testing.T) {
 		}
 	}
 }
+
+func TestGetHugePageSizeImpl(t *testing.T) {
+
+	testCases := []struct {
+		inputFiles      []string
+		outputPageSizes []string
+		err             error
+	}{
+		{
+			inputFiles:      []string{"hugepages-1048576kB", "hugepages-2048kB", "hugepages-32768kB", "hugepages-64kB"},
+			outputPageSizes: []string{"1GB", "2MB", "32MB", "64KB"},
+			err:             nil,
+		},
+		{
+			inputFiles:      []string{},
+			outputPageSizes: []string{},
+			err:             nil,
+		},
+		{
+			inputFiles:      []string{"hugepages-a"},
+			outputPageSizes: []string{},
+			err:             errors.New("invalid size: 'a'"),
+		},
+	}
+
+	for _, c := range testCases {
+		pageSizes, err := getHugePageSizeFromFilenames(c.inputFiles)
+		if len(pageSizes) != 0 && len(c.outputPageSizes) != 0 && !reflect.DeepEqual(pageSizes, c.outputPageSizes) {
+			t.Errorf("expected %s, got %s", c.outputPageSizes, pageSizes)
+		}
+		if err != nil && err.Error() != c.err.Error() {
+			t.Errorf("expected error %s, got %s", c.err, err)
+		}
+	}
+}