Subject: [patch] netpoll: fix netpoll lockups
From: Ingo Molnar <[email protected]>
current -git doesnt boot on my laptop due to the following netpoll
breakages:
- unlock the tx lock in the else branch too ...
- use irq-safe locking instead of bh-safe locking, netpoll is
often called from irq context.
with this patch -git boots fine with lockdep enabled and there are no
locking complaints and everything works fine. (The netpoll_send_skb()
portion of this patch was based on Andrew's bh-locking based netpoll
patch in -mm.)
Signed-off-by: Ingo Molnar <[email protected]>
---
net/core/netpoll.c | 39 ++++++++++++++++++++++++---------------
1 file changed, 24 insertions(+), 15 deletions(-)
Index: linux-hres-timers.q/net/core/netpoll.c
===================================================================
--- linux-hres-timers.q.orig/net/core/netpoll.c
+++ linux-hres-timers.q/net/core/netpoll.c
@@ -55,6 +55,7 @@ static void queue_process(struct work_st
struct netpoll_info *npinfo =
container_of(work, struct netpoll_info, tx_work.work);
struct sk_buff *skb;
+ unsigned long flags;
while ((skb = skb_dequeue(&npinfo->txq))) {
struct net_device *dev = skb->dev;
@@ -64,15 +65,19 @@ static void queue_process(struct work_st
continue;
}
- netif_tx_lock_bh(dev);
+ local_irq_save(flags);
+ netif_tx_lock(dev);
if (netif_queue_stopped(dev) ||
dev->hard_start_xmit(skb, dev) != NETDEV_TX_OK) {
skb_queue_head(&npinfo->txq, skb);
- netif_tx_unlock_bh(dev);
+ netif_tx_unlock(dev);
+ local_irq_restore(flags);
schedule_delayed_work(&npinfo->tx_work, HZ/10);
return;
}
+ netif_tx_unlock(dev);
+ local_irq_restore(flags);
}
}
@@ -231,7 +236,7 @@ repeat:
static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
{
int status = NETDEV_TX_BUSY;
- unsigned long tries;
+ unsigned long tries, flags;
struct net_device *dev = np->dev;
struct netpoll_info *npinfo = np->dev->npinfo;
@@ -242,22 +247,26 @@ static void netpoll_send_skb(struct netp
/* don't get messages out of order, and no recursion */
if (skb_queue_len(&npinfo->txq) == 0 &&
- npinfo->poll_owner != smp_processor_id() &&
- netif_tx_trylock(dev)) {
- /* try until next clock tick */
- for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; tries > 0; --tries) {
- if (!netif_queue_stopped(dev))
- status = dev->hard_start_xmit(skb, dev);
+ npinfo->poll_owner != smp_processor_id()) {
+ local_irq_save(flags); /* Where's netif_tx_trylock_irqsave()? */
+ if (netif_tx_trylock(dev)) {
+ /* try until next clock tick */
+ for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
+ tries > 0; --tries) {
+ if (!netif_queue_stopped(dev))
+ status = dev->hard_start_xmit(skb, dev);
- if (status == NETDEV_TX_OK)
- break;
+ if (status == NETDEV_TX_OK)
+ break;
- /* tickle device maybe there is some cleanup */
- netpoll_poll(np);
+ /* tickle device maybe there is some cleanup */
+ netpoll_poll(np);
- udelay(USEC_PER_POLL);
+ udelay(USEC_PER_POLL);
+ }
+ netif_tx_unlock(dev);
}
- netif_tx_unlock(dev);
+ local_irq_restore(flags);
}
if (status != NETDEV_TX_OK) {
-
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