diff options
Diffstat (limited to 'net/atm')
| -rw-r--r-- | net/atm/br2684.c | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/net/atm/br2684.c b/net/atm/br2684.c index 4819d31533e0..8eb6fbe8d8dd 100644 --- a/net/atm/br2684.c +++ b/net/atm/br2684.c @@ -74,6 +74,7 @@ struct br2684_vcc { struct br2684_filter filter; #endif /* CONFIG_ATM_BR2684_IPFILTER */ unsigned int copies_needed, copies_failed; + atomic_t qspace; }; struct br2684_dev { @@ -181,18 +182,15 @@ static struct notifier_block atm_dev_notifier = { static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb) { struct br2684_vcc *brvcc = BR2684_VCC(vcc); - struct net_device *net_dev = skb->dev; - pr_debug("(vcc %p ; net_dev %p )\n", vcc, net_dev); + pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device); brvcc->old_pop(vcc, skb); - if (!net_dev) - return; - - if (atm_may_send(vcc, 0)) - netif_wake_queue(net_dev); - + /* If the queue space just went up from zero, wake */ + if (atomic_inc_return(&brvcc->qspace) == 1) + netif_wake_queue(brvcc->device); } + /* * Send a packet out a particular vcc. Not to useful right now, but paves * the way for multiple vcc's per itf. Returns true if we can send, @@ -256,16 +254,19 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev, ATM_SKB(skb)->atm_options = atmvcc->atm_options; dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; - atmvcc->send(atmvcc, skb); - if (!atm_may_send(atmvcc, 0)) { + if (atomic_dec_return(&brvcc->qspace) < 1) { + /* No more please! */ netif_stop_queue(brvcc->device); - /*check for race with br2684_pop*/ - if (atm_may_send(atmvcc, 0)) - netif_start_queue(brvcc->device); + /* We might have raced with br2684_pop() */ + if (unlikely(atomic_read(&brvcc->qspace) > 0)) + netif_wake_queue(brvcc->device); } - return 1; + /* If this fails immediately, the skb will be freed and br2684_pop() + will wake the queue if appropriate. Just return an error so that + the stats are updated correctly */ + return !atmvcc->send(atmvcc, skb); } static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb, @@ -504,6 +505,13 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg) brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL); if (!brvcc) return -ENOMEM; + /* + * Allow two packets in the ATM queue. One actually being sent, and one + * for the ATM 'TX done' handler to send. It shouldn't take long to get + * the next one from the netdev queue, when we need it. More than that + * would be bufferbloat. + */ + atomic_set(&brvcc->qspace, 2); write_lock_irq(&devs_lock); net_dev = br2684_find_dev(&be.ifspec); if (net_dev == NULL) { |