diff options
| author | David S. Miller <davem@davemloft.net> | 2008-07-15 03:03:33 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-07-17 19:21:10 -0700 |
| commit | eae792b722fef08dcf3aee88266ee7def9710757 (patch) | |
| tree | a864c90974a8e998d56ee9f04801eb3f81a6bacf | |
| parent | e3c50d5d25ac09efd9acbe2b2a3e365466de84ed (diff) | |
netdev: Add netdev->select_queue() method.
Devices or device layers can set this to control the queue selection
performed by dev_pick_tx().
This function runs under RCU protection, which allows overriding
functions to have some way of synchronizing with things like dynamic
->real_num_tx_queues adjustments.
This makes the spinlock prefetch in dev_queue_xmit() a little bit
less effective, but that's the price right now for correctness.
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/netdevice.h | 3 | ||||
| -rw-r--r-- | net/core/dev.c | 9 |
2 files changed, 9 insertions, 3 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index fdac1159253..9464e645296 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -724,6 +724,9 @@ struct net_device void (*poll_controller)(struct net_device *dev); #endif + u16 (*select_queue)(struct net_device *dev, + struct sk_buff *skb); + #ifdef CONFIG_NET_NS /* Network namespace this network device is inside */ struct net *nd_net; diff --git a/net/core/dev.c b/net/core/dev.c index f027a1ac4fb..7ca9564d2f4 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1670,6 +1670,9 @@ static struct netdev_queue *dev_pick_tx(struct net_device *dev, { u16 queue_index = 0; + if (dev->select_queue) + queue_index = dev->select_queue(dev, skb); + skb_set_queue_mapping(skb, queue_index); return netdev_get_tx_queue(dev, queue_index); } @@ -1710,14 +1713,14 @@ int dev_queue_xmit(struct sk_buff *skb) } gso: - txq = dev_pick_tx(dev, skb); - spin_lock_prefetch(&txq->lock); - /* Disable soft irqs for various locks below. Also * stops preemption for RCU. */ rcu_read_lock_bh(); + txq = dev_pick_tx(dev, skb); + spin_lock_prefetch(&txq->lock); + /* Updates of qdisc are serialized by queue->lock. * The struct Qdisc which is pointed to by qdisc is now a * rcu structure - it may be accessed without acquiring |