@@ -76,22 +76,42 @@ func (s *statsCollector) unsubscribe(c *Container, ch chan interface{}) {

 }

 func (s *statsCollector) run() {

+	type publishersPair struct {

+		container *Container

+		publisher *pubsub.Publisher

+	}

+	// we cannot determine the capacity here.

+	// it will grow enough in first iteration

+	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]

+

+		s.m.Lock()

 		for container, publisher := range s.publishers {

-			systemUsage, err := s.getSystemCpuUsage()

-			if err != nil {

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

-				continue

-			}

-			stats, err := container.Stats()

+			// copy pointers here to release the lock ASAP

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

+		}

+		s.m.Unlock()

+

+		for _, pair := range pairs {

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

 			if err != nil {

 				if err != execdriver.ErrNotRunning {

-					logrus.Errorf("collecting stats for %s: %v", container.ID, err)

+					logrus.Errorf("collecting stats for %s: %v", pair.container.ID, err)

 				}

 				continue

 			}

 			stats.SystemUsage = systemUsage

-			publisher.Publish(stats)

+			pair.publisher.Publish(stats)

 		}

 	}

 }