diff options
Diffstat (limited to 'net/sched/sch_generic.c')
-rw-r--r-- | net/sched/sch_generic.c | 108 |
1 files changed, 44 insertions, 64 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 7cf83b37459..7b5572d6beb 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -44,23 +44,30 @@ static inline int qdisc_qlen(struct Qdisc *q) static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q) { - if (unlikely(skb->next)) - q->gso_skb = skb; - else - q->ops->requeue(skb, q); - + q->gso_skb = skb; + q->qstats.requeues++; __netif_schedule(q); + return 0; } static inline struct sk_buff *dequeue_skb(struct Qdisc *q) { - struct sk_buff *skb; + struct sk_buff *skb = q->gso_skb; - if ((skb = q->gso_skb)) - q->gso_skb = NULL; - else + if (unlikely(skb)) { + struct net_device *dev = qdisc_dev(q); + struct netdev_queue *txq; + + /* check the reason of requeuing without tx lock first */ + txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); + if (!netif_tx_queue_stopped(txq) && !netif_tx_queue_frozen(txq)) + q->gso_skb = NULL; + else + skb = NULL; + } else { skb = q->dequeue(q); + } return skb; } @@ -215,10 +222,9 @@ static void dev_watchdog(unsigned long arg) time_after(jiffies, (dev->trans_start + dev->watchdog_timeo))) { char drivername[64]; - printk(KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit timed out\n", + WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit timed out\n", dev->name, netdev_drivername(dev, drivername, 64)); dev->tx_timeout(dev); - WARN_ON_ONCE(1); } if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + @@ -328,6 +334,7 @@ struct Qdisc noop_qdisc = { .flags = TCQ_F_BUILTIN, .ops = &noop_qdisc_ops, .list = LIST_HEAD_INIT(noop_qdisc.list), + .requeue.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock), .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock), .dev_queue = &noop_netdev_queue, }; @@ -353,6 +360,7 @@ static struct Qdisc noqueue_qdisc = { .flags = TCQ_F_BUILTIN, .ops = &noqueue_qdisc_ops, .list = LIST_HEAD_INIT(noqueue_qdisc.list), + .requeue.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock), .q.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock), .dev_queue = &noqueue_netdev_queue, }; @@ -473,6 +481,7 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, sch->padded = (char *) sch - (char *) p; INIT_LIST_HEAD(&sch->list); + skb_queue_head_init(&sch->requeue); skb_queue_head_init(&sch->q); sch->ops = ops; sch->enqueue = ops->enqueue; @@ -518,15 +527,17 @@ void qdisc_reset(struct Qdisc *qdisc) } EXPORT_SYMBOL(qdisc_reset); -/* this is the rcu callback function to clean up a qdisc when there - * are no further references to it */ - -static void __qdisc_destroy(struct rcu_head *head) +void qdisc_destroy(struct Qdisc *qdisc) { - struct Qdisc *qdisc = container_of(head, struct Qdisc, q_rcu); const struct Qdisc_ops *ops = qdisc->ops; + if (qdisc->flags & TCQ_F_BUILTIN || + !atomic_dec_and_test(&qdisc->refcnt)) + return; + #ifdef CONFIG_NET_SCHED + qdisc_list_del(qdisc); + qdisc_put_stab(qdisc->stab); #endif gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est); @@ -539,23 +550,10 @@ static void __qdisc_destroy(struct rcu_head *head) dev_put(qdisc_dev(qdisc)); kfree_skb(qdisc->gso_skb); + __skb_queue_purge(&qdisc->requeue); kfree((char *) qdisc - qdisc->padded); } - -/* Under qdisc_lock(qdisc) and BH! */ - -void qdisc_destroy(struct Qdisc *qdisc) -{ - if (qdisc->flags & TCQ_F_BUILTIN || - !atomic_dec_and_test(&qdisc->refcnt)) - return; - - if (qdisc->parent) - list_del(&qdisc->list); - - call_rcu(&qdisc->q_rcu, __qdisc_destroy); -} EXPORT_SYMBOL(qdisc_destroy); static bool dev_all_qdisc_sleeping_noop(struct net_device *dev) @@ -597,6 +595,9 @@ static void transition_one_qdisc(struct net_device *dev, struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping; int *need_watchdog_p = _need_watchdog; + if (!(new_qdisc->flags & TCQ_F_BUILTIN)) + clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state); + rcu_assign_pointer(dev_queue->qdisc, new_qdisc); if (need_watchdog_p && new_qdisc != &noqueue_qdisc) *need_watchdog_p = 1; @@ -640,14 +641,17 @@ static void dev_deactivate_queue(struct net_device *dev, if (qdisc) { spin_lock_bh(qdisc_lock(qdisc)); - dev_queue->qdisc = qdisc_default; + if (!(qdisc->flags & TCQ_F_BUILTIN)) + set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); + + rcu_assign_pointer(dev_queue->qdisc, qdisc_default); qdisc_reset(qdisc); spin_unlock_bh(qdisc_lock(qdisc)); } } -static bool some_qdisc_is_running(struct net_device *dev, int lock) +static bool some_qdisc_is_busy(struct net_device *dev) { unsigned int i; @@ -658,16 +662,15 @@ static bool some_qdisc_is_running(struct net_device *dev, int lock) int val; dev_queue = netdev_get_tx_queue(dev, i); - q = dev_queue->qdisc; + q = dev_queue->qdisc_sleeping; root_lock = qdisc_lock(q); - if (lock) - spin_lock_bh(root_lock); + spin_lock_bh(root_lock); - val = test_bit(__QDISC_STATE_RUNNING, &q->state); + val = (test_bit(__QDISC_STATE_RUNNING, &q->state) || + test_bit(__QDISC_STATE_SCHED, &q->state)); - if (lock) - spin_unlock_bh(root_lock); + spin_unlock_bh(root_lock); if (val) return true; @@ -677,8 +680,6 @@ static bool some_qdisc_is_running(struct net_device *dev, int lock) void dev_deactivate(struct net_device *dev) { - bool running; - netdev_for_each_tx_queue(dev, dev_deactivate_queue, &noop_qdisc); dev_deactivate_queue(dev, &dev->rx_queue, &noop_qdisc); @@ -688,25 +689,8 @@ void dev_deactivate(struct net_device *dev) synchronize_rcu(); /* Wait for outstanding qdisc_run calls. */ - do { - while (some_qdisc_is_running(dev, 0)) - yield(); - - /* - * Double-check inside queue lock to ensure that all effects - * of the queue run are visible when we return. - */ - running = some_qdisc_is_running(dev, 1); - - /* - * The running flag should never be set at this point because - * we've already set dev->qdisc to noop_qdisc *inside* the same - * pair of spin locks. That is, if any qdisc_run starts after - * our initial test it should see the noop_qdisc and then - * clear the RUNNING bit before dropping the queue lock. So - * if it is set here then we've found a bug. - */ - } while (WARN_ON_ONCE(running)); + while (some_qdisc_is_busy(dev)) + yield(); } static void dev_init_scheduler_queue(struct net_device *dev, @@ -735,14 +719,10 @@ static void shutdown_scheduler_queue(struct net_device *dev, struct Qdisc *qdisc_default = _qdisc_default; if (qdisc) { - spinlock_t *root_lock = qdisc_lock(qdisc); - - dev_queue->qdisc = qdisc_default; + rcu_assign_pointer(dev_queue->qdisc, qdisc_default); dev_queue->qdisc_sleeping = qdisc_default; - spin_lock_bh(root_lock); qdisc_destroy(qdisc); - spin_unlock_bh(root_lock); } } |