diff options
| author | Stephen Hemminger <shemminger@linux-foundation.org> | 2007-03-16 14:01:30 -0700 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2007-04-28 11:01:00 -0400 |
| commit | 992c9623b148ba939e9cdba0d668eedd3af1a5d2 (patch) | |
| tree | 4593ab3e61d2f58023d4af4397a0b23fefe65abc /drivers/net/skge.c | |
| parent | 7e0038a414c38085dfbf352f21006bcca4cd308b (diff) | |
skge: transmit locking improvements
Don't need to lock when processing transmit complete unless queue fills.
Modeled after tg3.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/net/skge.c')
| -rw-r--r-- | drivers/net/skge.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/drivers/net/skge.c b/drivers/net/skge.c index f1a0e6c0fbd..bc531fdfc8e 100644 --- a/drivers/net/skge.c +++ b/drivers/net/skge.c @@ -2621,6 +2621,7 @@ static int skge_down(struct net_device *dev) static inline int skge_avail(const struct skge_ring *ring) { + smp_mb(); return ((ring->to_clean > ring->to_use) ? 0 : ring->count) + (ring->to_clean - ring->to_use) - 1; } @@ -2709,6 +2710,8 @@ static int skge_xmit_frame(struct sk_buff *skb, struct net_device *dev) dev->name, e - skge->tx_ring.start, skb->len); skge->tx_ring.to_use = e->next; + smp_wmb(); + if (skge_avail(&skge->tx_ring) <= TX_LOW_WATER) { pr_debug("%s: transmit queue full\n", dev->name); netif_stop_queue(dev); @@ -2726,8 +2729,6 @@ static void skge_tx_free(struct skge_port *skge, struct skge_element *e, { struct pci_dev *pdev = skge->hw->pdev; - BUG_ON(!e->skb); - /* skb header vs. fragment */ if (control & BMU_STF) pci_unmap_single(pdev, pci_unmap_addr(e, mapaddr), @@ -2745,7 +2746,6 @@ static void skge_tx_free(struct skge_port *skge, struct skge_element *e, dev_kfree_skb(e->skb); } - e->skb = NULL; } /* Free all buffers in transmit ring */ @@ -3017,21 +3017,29 @@ static void skge_tx_done(struct net_device *dev) skge_write8(skge->hw, Q_ADDR(txqaddr[skge->port], Q_CSR), CSR_IRQ_CL_F); - netif_tx_lock(dev); for (e = ring->to_clean; e != ring->to_use; e = e->next) { - struct skge_tx_desc *td = e->desc; + u32 control = ((const struct skge_tx_desc *) e->desc)->control; - if (td->control & BMU_OWN) + if (control & BMU_OWN) break; - skge_tx_free(skge, e, td->control); + skge_tx_free(skge, e, control); } skge->tx_ring.to_clean = e; - if (skge_avail(&skge->tx_ring) > TX_LOW_WATER) - netif_wake_queue(dev); + /* Can run lockless until we need to synchronize to restart queue. */ + smp_mb(); + + if (unlikely(netif_queue_stopped(dev) && + skge_avail(&skge->tx_ring) > TX_LOW_WATER)) { + netif_tx_lock(dev); + if (unlikely(netif_queue_stopped(dev) && + skge_avail(&skge->tx_ring) > TX_LOW_WATER)) { + netif_wake_queue(dev); - netif_tx_unlock(dev); + } + netif_tx_unlock(dev); + } } static int skge_poll(struct net_device *dev, int *budget) |