diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/dev.c | 48 | ||||
| -rw-r--r-- | net/sched/sch_generic.c | 93 |
2 files changed, 92 insertions, 49 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index f01a9c41f112..a0bc087616a4 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1786,6 +1786,40 @@ static struct netdev_queue *dev_pick_tx(struct net_device *dev, return netdev_get_tx_queue(dev, queue_index); } +static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, + struct net_device *dev, + struct netdev_queue *txq) +{ + spinlock_t *root_lock = qdisc_lock(q); + int rc; + + spin_lock(root_lock); + if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) { + kfree_skb(skb); + rc = NET_XMIT_DROP; + } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) && + !test_and_set_bit(__QDISC_STATE_RUNNING, &q->state)) { + /* + * This is a work-conserving queue; there are no old skbs + * waiting to be sent out; and the qdisc is not running - + * xmit the skb directly. + */ + __qdisc_update_bstats(q, skb->len); + if (sch_direct_xmit(skb, q, dev, txq, root_lock)) + __qdisc_run(q); + else + clear_bit(__QDISC_STATE_RUNNING, &q->state); + + rc = NET_XMIT_SUCCESS; + } else { + rc = qdisc_enqueue_root(skb, q); + qdisc_run(q); + } + spin_unlock(root_lock); + + return rc; +} + /** * dev_queue_xmit - transmit a buffer * @skb: buffer to transmit @@ -1859,19 +1893,7 @@ gso: skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_EGRESS); #endif if (q->enqueue) { - spinlock_t *root_lock = qdisc_lock(q); - - spin_lock(root_lock); - - if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) { - kfree_skb(skb); - rc = NET_XMIT_DROP; - } else { - rc = qdisc_enqueue_root(skb, q); - qdisc_run(q); - } - spin_unlock(root_lock); - + rc = __dev_xmit_skb(skb, q, dev, txq); goto out; } diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 27d03816ec3e..693df7ae33d8 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -37,15 +37,11 @@ * - updates to tree and tree walking are only done under the rtnl mutex. */ -static inline int qdisc_qlen(struct Qdisc *q) -{ - return q->q.qlen; -} - static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q) { q->gso_skb = skb; q->qstats.requeues++; + q->q.qlen++; /* it's still part of the queue */ __netif_schedule(q); return 0; @@ -61,9 +57,11 @@ static inline struct sk_buff *dequeue_skb(struct Qdisc *q) /* 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)) + if (!netif_tx_queue_stopped(txq) && + !netif_tx_queue_frozen(txq)) { q->gso_skb = NULL; - else + q->q.qlen--; + } else skb = NULL; } else { skb = q->dequeue(q); @@ -103,44 +101,23 @@ static inline int handle_dev_cpu_collision(struct sk_buff *skb, } /* - * NOTE: Called under qdisc_lock(q) with locally disabled BH. - * - * __QDISC_STATE_RUNNING guarantees only one CPU can process - * this qdisc at a time. qdisc_lock(q) serializes queue accesses for - * this queue. - * - * netif_tx_lock serializes accesses to device driver. - * - * qdisc_lock(q) and netif_tx_lock are mutually exclusive, - * if one is grabbed, another must be free. - * - * Note, that this procedure can be called by a watchdog timer + * Transmit one skb, and handle the return status as required. Holding the + * __QDISC_STATE_RUNNING bit guarantees that only one CPU can execute this + * function. * * Returns to the caller: * 0 - queue is empty or throttled. * >0 - queue is not empty. - * */ -static inline int qdisc_restart(struct Qdisc *q) +int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, + struct net_device *dev, struct netdev_queue *txq, + spinlock_t *root_lock) { - struct netdev_queue *txq; int ret = NETDEV_TX_BUSY; - struct net_device *dev; - spinlock_t *root_lock; - struct sk_buff *skb; - - /* Dequeue packet */ - if (unlikely((skb = dequeue_skb(q)) == NULL)) - return 0; - - root_lock = qdisc_lock(q); /* And release qdisc */ spin_unlock(root_lock); - dev = qdisc_dev(q); - txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); - HARD_TX_LOCK(dev, txq, smp_processor_id()); if (!netif_tx_queue_stopped(txq) && !netif_tx_queue_frozen(txq)) @@ -177,6 +154,44 @@ static inline int qdisc_restart(struct Qdisc *q) return ret; } +/* + * NOTE: Called under qdisc_lock(q) with locally disabled BH. + * + * __QDISC_STATE_RUNNING guarantees only one CPU can process + * this qdisc at a time. qdisc_lock(q) serializes queue accesses for + * this queue. + * + * netif_tx_lock serializes accesses to device driver. + * + * qdisc_lock(q) and netif_tx_lock are mutually exclusive, + * if one is grabbed, another must be free. + * + * Note, that this procedure can be called by a watchdog timer + * + * Returns to the caller: + * 0 - queue is empty or throttled. + * >0 - queue is not empty. + * + */ +static inline int qdisc_restart(struct Qdisc *q) +{ + struct netdev_queue *txq; + struct net_device *dev; + spinlock_t *root_lock; + struct sk_buff *skb; + + /* Dequeue packet */ + skb = dequeue_skb(q); + if (unlikely(!skb)) + return 0; + + root_lock = qdisc_lock(q); + dev = qdisc_dev(q); + txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); + + return sch_direct_xmit(skb, q, dev, txq, root_lock); +} + void __qdisc_run(struct Qdisc *q) { unsigned long start_time = jiffies; @@ -547,8 +562,11 @@ void qdisc_reset(struct Qdisc *qdisc) if (ops->reset) ops->reset(qdisc); - kfree_skb(qdisc->gso_skb); - qdisc->gso_skb = NULL; + if (qdisc->gso_skb) { + kfree_skb(qdisc->gso_skb); + qdisc->gso_skb = NULL; + qdisc->q.qlen = 0; + } } EXPORT_SYMBOL(qdisc_reset); @@ -605,6 +623,9 @@ static void attach_one_default_qdisc(struct net_device *dev, printk(KERN_INFO "%s: activation failed\n", dev->name); return; } + + /* Can by-pass the queue discipline for default qdisc */ + qdisc->flags |= TCQ_F_CAN_BYPASS; } else { qdisc = &noqueue_qdisc; } |