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IPoIB: Use netif_tx_lock() and get rid of private tx_lock, LLTX

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Currently, IPoIB is an LLTX driver that uses its own IRQ-disabling
tx_lock.  Not only do we want to get rid of LLTX, this actually causes
problems because of the skb_orphan() done with this tx_lock held: some
skb destructors expect to be run with interrupts enabled.

The simplest fix for this is to get rid of the driver-private tx_lock
and stop using LLTX.  We kill off priv->tx_lock and use
netif_tx_lock[_bh]() instead; the patch to do this is a tiny bit
tricky because we need to update places that take priv->lock inside
the tx_lock to disable IRQs, rather than relying on tx_lock having
already disabled IRQs.

Also, there are a couple of places where we need to disable BHs to
make sure we have a consistent context to call netif_tx_lock() (since
we no longer can use _irqsave() variants), and we also have to change
ipoib_send_comp_handler() to call drain_tx_cq() through a timer rather
than directly, because ipoib_send_comp_handler() runs in interrupt
context and drain_tx_cq() must run in BH context so it can call
netif_tx_lock().

Signed-off-by: Roland Dreier <rolandd@cisco.com>
This commit is contained in:
Roland Dreier
2008-09-30 10:36:21 -07:00
parent c9da4bad5b
commit 943c246e9b
5 changed files with 118 additions and 107 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
drivers/infiniband/ulp/ipoib/ipoib_multicast.c
View File

@ -69,14 +69,13 @@ static void ipoib_mcast_free(struct ipoib_mcast *mcast)
struct net_device *dev = mcast->dev;
struct ipoib_dev_priv *priv = netdev_priv(dev);
struct ipoib_neigh *neigh, *tmp;
unsigned long flags;
int tx_dropped = 0;
ipoib_dbg_mcast(netdev_priv(dev),
"deleting multicast group " IPOIB_GID_FMT "\n",
IPOIB_GID_ARG(mcast->mcmember.mgid));
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irq(&priv->lock);
list_for_each_entry_safe(neigh, tmp, &mcast->neigh_list, list) {
/*
@ -90,7 +89,7 @@ static void ipoib_mcast_free(struct ipoib_mcast *mcast)
ipoib_neigh_free(dev, neigh);
}
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irq(&priv->lock);
if (mcast->ah)
ipoib_put_ah(mcast->ah);
@ -100,9 +99,9 @@ static void ipoib_mcast_free(struct ipoib_mcast *mcast)
dev_kfree_skb_any(skb_dequeue(&mcast->pkt_queue));
}
spin_lock_irqsave(&priv->tx_lock, flags);
netif_tx_lock_bh(dev);
dev->stats.tx_dropped += tx_dropped;
spin_unlock_irqrestore(&priv->tx_lock, flags);
netif_tx_unlock_bh(dev);
kfree(mcast);
}
@ -259,10 +258,10 @@ static int ipoib_mcast_join_finish(struct ipoib_mcast *mcast,
}
/* actually send any queued packets */
spin_lock_irq(&priv->tx_lock);
netif_tx_lock_bh(dev);
while (!skb_queue_empty(&mcast->pkt_queue)) {
struct sk_buff *skb = skb_dequeue(&mcast->pkt_queue);
spin_unlock_irq(&priv->tx_lock);
netif_tx_unlock_bh(dev);
skb->dev = dev;
@ -273,9 +272,9 @@ static int ipoib_mcast_join_finish(struct ipoib_mcast *mcast,
if (dev_queue_xmit(skb))
ipoib_warn(priv, "dev_queue_xmit failed to requeue packet\n");
spin_lock_irq(&priv->tx_lock);
netif_tx_lock_bh(dev);
}
spin_unlock_irq(&priv->tx_lock);
netif_tx_unlock_bh(dev);
return 0;
}
@ -286,7 +285,6 @@ ipoib_mcast_sendonly_join_complete(int status,
{
struct ipoib_mcast *mcast = multicast->context;
struct net_device *dev = mcast->dev;
struct ipoib_dev_priv *priv = netdev_priv(dev);
/* We trap for port events ourselves. */
if (status == -ENETRESET)
@ -302,12 +300,12 @@ ipoib_mcast_sendonly_join_complete(int status,
IPOIB_GID_ARG(mcast->mcmember.mgid), status);
/* Flush out any queued packets */
spin_lock_irq(&priv->tx_lock);
netif_tx_lock_bh(dev);
while (!skb_queue_empty(&mcast->pkt_queue)) {
++dev->stats.tx_dropped;
dev_kfree_skb_any(skb_dequeue(&mcast->pkt_queue));
}
spin_unlock_irq(&priv->tx_lock);
netif_tx_unlock_bh(dev);
/* Clear the busy flag so we try again */
status = test_and_clear_bit(IPOIB_MCAST_FLAG_BUSY,
@ -662,12 +660,9 @@ void ipoib_mcast_send(struct net_device *dev, void *mgid, struct sk_buff *skb)
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
struct ipoib_mcast *mcast;
unsigned long flags;
/*
* We can only be called from ipoib_start_xmit, so we're
* inside tx_lock -- no need to save/restore flags.
*/
spin_lock(&priv->lock);
spin_lock_irqsave(&priv->lock, flags);
if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags) ||
!priv->broadcast ||
@ -738,7 +733,7 @@ out:
}
unlock:
spin_unlock(&priv->lock);
spin_unlock_irqrestore(&priv->lock, flags);
}
void ipoib_mcast_dev_flush(struct net_device *dev)