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| author | Jarek Poplawski <jarkao2@gmail.com> | 2008-09-22 22:16:23 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-09-22 22:16:23 -0700 |
| commit | ebf059821ed8a36acd706484b719d14d212ada32 (patch) | |
| tree | 44b2ee2887113ea5d90b35f4c4ae1a376f38e94f /net/sched/sch_generic.c | |
| parent | f0876520b0b721bedafd9cec3b1b0624ae566eee (diff) | |
| download | lwn-ebf059821ed8a36acd706484b719d14d212ada32.tar.gz lwn-ebf059821ed8a36acd706484b719d14d212ada32.zip | |
pkt_sched: Check the state of tx_queue in dequeue_skb()
Check in dequeue_skb() the state of tx_queue for requeued skb to save
on locking and re-requeuing, and possibly remove the current check in
qdisc_run(). Based on the idea of Alexander Duyck.
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_generic.c')
| -rw-r--r-- | net/sched/sch_generic.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 1b508bd1c06c..5e7e0bd38fe8 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -52,11 +52,21 @@ static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q) static inline struct sk_buff *dequeue_skb(struct Qdisc *q) { - struct sk_buff *skb; - - skb = __skb_dequeue(&q->requeue); - if (!skb) + struct sk_buff *skb = skb_peek(&q->requeue); + + 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)) + __skb_unlink(skb, &q->requeue); + else + skb = NULL; + } else { skb = q->dequeue(q); + } return skb; } |