@@ -89,12 +89,6 @@ func (s *statsCollector) run() {

 	var pairs []publishersPair

 	for range time.Tick(s.interval) {

-		systemUsage, err := s.getSystemCPUUsage()

-		if err != nil {

-			logrus.Errorf("collecting system cpu usage: %v", err)

-			continue

-		}

-

 		// it does not make sense in the first iteration,

 		// but saves allocations in further iterations

 		pairs = pairs[:0]

@@ -105,6 +99,15 @@ func (s *statsCollector) run() {

 			pairs = append(pairs, publishersPair{container, publisher})

 		}

 		s.m.Unlock()

+		if len(pairs) == 0 {

+			continue

+		}

+

+		systemUsage, err := s.getSystemCPUUsage()

+		if err != nil {

+			logrus.Errorf("collecting system cpu usage: %v", err)

+			continue

+		}

 		for _, pair := range pairs {

 			stats, err := pair.container.stats()