diff --git a/libcontainer/intelrdt/intelrdt.go b/libcontainer/intelrdt/intelrdt.go
index 8b6bf3ef0..07e4e1fd9 100644
--- a/libcontainer/intelrdt/intelrdt.go
+++ b/libcontainer/intelrdt/intelrdt.go
@@ -276,35 +276,30 @@ func findIntelRdtMountpointDir(f io.Reader) (string, error) {
 
 // For Root() use only.
 var (
-	intelRdtRoot string
-	rootMu       sync.Mutex
+	intelRdtRoot    string
+	intelRdtRootErr error
+	rootOnce        sync.Once
 )
 
 // Root returns the Intel RDT "resource control" filesystem mount point.
 func Root() (string, error) {
-	rootMu.Lock()
-	defer rootMu.Unlock()
+	rootOnce.Do(func() {
+		f, err := os.Open("/proc/self/mountinfo")
+		if err != nil {
+			intelRdtRootErr = err
+			return
+		}
+		root, err := findIntelRdtMountpointDir(f)
+		f.Close()
+		if err != nil {
+			intelRdtRootErr = err
+			return
+		}
 
-	if intelRdtRoot != "" {
-		return intelRdtRoot, nil
-	}
+		intelRdtRoot = root
+	})
 
-	f, err := os.Open("/proc/self/mountinfo")
-	if err != nil {
-		return "", err
-	}
-	root, err := findIntelRdtMountpointDir(f)
-	f.Close()
-	if err != nil {
-		return "", err
-	}
-
-	if _, err := os.Stat(root); err != nil {
-		return "", err
-	}
-
-	intelRdtRoot = root
-	return intelRdtRoot, nil
+	return intelRdtRoot, intelRdtRootErr
 }
 
 type cpuInfoFlags struct {
diff --git a/libcontainer/intelrdt/util_test.go b/libcontainer/intelrdt/util_test.go
index f1b4244e2..b29d685e9 100644
--- a/libcontainer/intelrdt/util_test.go
+++ b/libcontainer/intelrdt/util_test.go
@@ -26,7 +26,12 @@ func NewIntelRdtTestUtil(t *testing.T) *intelRdtTestUtil {
 	config := &configs.Config{
 		IntelRdt: &configs.IntelRdt{},
 	}
+
+	// Assign fake intelRtdRoot value, returned by Root().
 	intelRdtRoot = t.TempDir()
+	// Make sure Root() won't even try to parse mountinfo.
+	rootOnce.Do(func() {})
+
 	testIntelRdtPath := filepath.Join(intelRdtRoot, "resctrl")
 
 	// Ensure the full mock Intel RDT "resource control" filesystem path exists