net: txq_trans_update() helper

We would like to get rid of netdev->trans_start = jiffies; that about all net
drivers have to use in their start_xmit() function, and use txq->trans_start
instead.

This can be done generically in core network, as suggested by David.

Some devices, (particularly loopback) dont need trans_start update, because
they dont have transmit watchdog. We could add a new device flag, or rely
on fact that txq->tran_start can be updated is txq->xmit_lock_owner is
different than -1. Use a helper function to hide our choice.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2009-05-25 22:58:01 -07:00 committed by David S. Miller
parent 65ac885149
commit 08baf56108
5 changed files with 15 additions and 1 deletions

View File

@ -1674,6 +1674,12 @@ static inline void __netif_tx_unlock_bh(struct netdev_queue *txq)
spin_unlock_bh(&txq->_xmit_lock);
}
static inline void txq_trans_update(struct netdev_queue *txq)
{
if (txq->xmit_lock_owner != -1)
txq->trans_start = jiffies;
}
/**
* netif_tx_lock - grab network device transmit lock
* @dev: network device

View File

@ -1698,6 +1698,8 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
skb->dst = NULL;
}
rc = ops->ndo_start_xmit(skb, dev);
if (rc == 0)
txq_trans_update(txq);
/*
* TODO: if skb_orphan() was called by
* dev->hard_start_xmit() (for example, the unmodified
@ -1727,6 +1729,7 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
skb->next = nskb;
return rc;
}
txq_trans_update(txq);
if (unlikely(netif_tx_queue_stopped(txq) && skb->next))
return NETDEV_TX_BUSY;
} while (skb->next);

View File

@ -302,8 +302,11 @@ static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
tries > 0; --tries) {
if (__netif_tx_trylock(txq)) {
if (!netif_tx_queue_stopped(txq))
if (!netif_tx_queue_stopped(txq)) {
status = ops->ndo_start_xmit(skb, dev);
if (status == NETDEV_TX_OK)
txq_trans_update(txq);
}
__netif_tx_unlock(txq);
if (status == NETDEV_TX_OK)

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@ -3438,6 +3438,7 @@ static __inline__ void pktgen_xmit(struct pktgen_dev *pkt_dev)
retry_now:
ret = (*xmit)(pkt_dev->skb, odev);
if (likely(ret == NETDEV_TX_OK)) {
txq_trans_update(txq);
pkt_dev->last_ok = 1;
pkt_dev->sofar++;
pkt_dev->seq_num++;

View File

@ -308,6 +308,7 @@ static int teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
if (!netif_tx_queue_stopped(slave_txq) &&
!netif_tx_queue_frozen(slave_txq) &&
slave_ops->ndo_start_xmit(skb, slave) == 0) {
txq_trans_update(slave_txq);
__netif_tx_unlock(slave_txq);
master->slaves = NEXT_SLAVE(q);
netif_wake_queue(dev);