intelrdt: change parseCpuInfoFile to return struct

Signed-off-by: Paweł Szulik <pawel.szulik@intel.com>

libcontainer/intelrdt/intelrdt.go

@@ -191,8 +191,7 @@ type intelRdtData struct {
 // Check if Intel RDT sub-features are enabled in init()
 func init() {
 	// 1. Check if hardware and kernel support Intel RDT sub-features
-	// "cat_l3" flag for CAT and "mba" flag for MBA
-	isCatFlagSet, isMbaFlagSet, err := parseCpuInfoFile("/proc/cpuinfo")
+	flagsSet, err := parseCpuInfoFile("/proc/cpuinfo")
 	if err != nil {
 		return
 	}
@@ -207,7 +206,7 @@ func init() {
 	// "resource control" filesystem. Intel RDT sub-features can be
 	// selectively disabled or enabled by kernel command line
 	// (e.g., rdt=!l3cat,mba) in 4.14 and newer kernel
-	if isCatFlagSet {
+	if flagsSet.CAT {
 		if _, err := os.Stat(filepath.Join(intelRdtRoot, "info", "L3")); err == nil {
 			isCatEnabled = true
 		}
@@ -217,7 +216,7 @@ func init() {
 		// MBA should be enabled because MBA Software Controller
 		// depends on MBA
 		isMbaEnabled = true
-	} else if isMbaFlagSet {
+	} else if flagsSet.MBA {
 		if _, err := os.Stat(filepath.Join(intelRdtRoot, "info", "MB")); err == nil {
 			isMbaEnabled = true
 		}
@@ -298,13 +297,17 @@ func isIntelRdtMounted() bool {
 	return true
 }
 
-func parseCpuInfoFile(path string) (bool, bool, error) {
-	isCatFlagSet := false
-	isMbaFlagSet := false
+type cpuInfoFlags struct {
+	CAT bool // Cache Allocation Technology
+	MBA bool // Memory Bandwidth Allocation
+}
+
+func parseCpuInfoFile(path string) (cpuInfoFlags, error) {
+	infoFlags := cpuInfoFlags{}
 
 	f, err := os.Open(path)
 	if err != nil {
-		return false, false, err
+		return infoFlags, err
 	}
 	defer f.Close()
 
@@ -319,19 +322,19 @@ func parseCpuInfoFile(path string) (bool, bool, error) {
 			for _, flag := range flags {
 				switch flag {
 				case "cat_l3":
-					isCatFlagSet = true
+					infoFlags.CAT = true
 				case "mba":
-					isMbaFlagSet = true
+					infoFlags.MBA = true
 				}
 			}
-			return isCatFlagSet, isMbaFlagSet, nil
+			return infoFlags, nil
 		}
 	}
 	if err := s.Err(); err != nil {
-		return false, false, err
+		return infoFlags, err
 	}
 
-	return isCatFlagSet, isMbaFlagSet, nil
+	return infoFlags, nil
 }
 
 func parseUint(s string, base, bitSize int) (uint64, error) {