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Diffstat (limited to 'net/sched/sch_generic.c')
-rw-r--r--net/sched/sch_generic.c31
1 files changed, 5 insertions, 26 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index ff1c4557e5f..30b76aec723 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -653,7 +653,7 @@ static void dev_deactivate_queue(struct net_device *dev,
653 } 653 }
654} 654}
655 655
656static bool some_qdisc_is_busy(struct net_device *dev, int lock) 656static bool some_qdisc_is_busy(struct net_device *dev)
657{ 657{
658 unsigned int i; 658 unsigned int i;
659 659
@@ -667,14 +667,12 @@ static bool some_qdisc_is_busy(struct net_device *dev, int lock)
667 q = dev_queue->qdisc_sleeping; 667 q = dev_queue->qdisc_sleeping;
668 root_lock = qdisc_lock(q); 668 root_lock = qdisc_lock(q);
669 669
670 if (lock) 670 spin_lock_bh(root_lock);
671 spin_lock_bh(root_lock);
672 671
673 val = (test_bit(__QDISC_STATE_RUNNING, &q->state) || 672 val = (test_bit(__QDISC_STATE_RUNNING, &q->state) ||
674 test_bit(__QDISC_STATE_SCHED, &q->state)); 673 test_bit(__QDISC_STATE_SCHED, &q->state));
675 674
676 if (lock) 675 spin_unlock_bh(root_lock);
677 spin_unlock_bh(root_lock);
678 676
679 if (val) 677 if (val)
680 return true; 678 return true;
@@ -684,8 +682,6 @@ static bool some_qdisc_is_busy(struct net_device *dev, int lock)
684 682
685void dev_deactivate(struct net_device *dev) 683void dev_deactivate(struct net_device *dev)
686{ 684{
687 bool running;
688
689 netdev_for_each_tx_queue(dev, dev_deactivate_queue, &noop_qdisc); 685 netdev_for_each_tx_queue(dev, dev_deactivate_queue, &noop_qdisc);
690 dev_deactivate_queue(dev, &dev->rx_queue, &noop_qdisc); 686 dev_deactivate_queue(dev, &dev->rx_queue, &noop_qdisc);
691 687
@@ -695,25 +691,8 @@ void dev_deactivate(struct net_device *dev)
695 synchronize_rcu(); 691 synchronize_rcu();
696 692
697 /* Wait for outstanding qdisc_run calls. */ 693 /* Wait for outstanding qdisc_run calls. */
698 do { 694 while (some_qdisc_is_busy(dev))
699 while (some_qdisc_is_busy(dev, 0)) 695 yield();
700 yield();
701
702 /*
703 * Double-check inside queue lock to ensure that all effects
704 * of the queue run are visible when we return.
705 */
706 running = some_qdisc_is_busy(dev, 1);
707
708 /*
709 * The running flag should never be set at this point because
710 * we've already set dev->qdisc to noop_qdisc *inside* the same
711 * pair of spin locks. That is, if any qdisc_run starts after
712 * our initial test it should see the noop_qdisc and then
713 * clear the RUNNING bit before dropping the queue lock. So
714 * if it is set here then we've found a bug.
715 */
716 } while (WARN_ON_ONCE(running));
717} 696}
718 697
719static void dev_init_scheduler_queue(struct net_device *dev, 698static void dev_init_scheduler_queue(struct net_device *dev,