netpoll retry cleanup
The netpoll beast was still not happy. If the beast got
clogged pipes, it tended to stare blankly off in space
for a long time.
The problem couldn't be completely fixed because the
beast talked with irq's disabled. But it could be made
less painful and shorter.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 93cb828..6b34c39 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -34,12 +34,12 @@
#define MAX_UDP_CHUNK 1460
#define MAX_SKBS 32
#define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
-#define MAX_RETRIES 20000
static struct sk_buff_head skb_pool;
static atomic_t trapped;
+#define USEC_PER_POLL 50
#define NETPOLL_RX_ENABLED 1
#define NETPOLL_RX_DROP 2
@@ -72,6 +72,7 @@
schedule_delayed_work(&npinfo->tx_work, HZ/10);
return;
}
+
netif_tx_unlock_bh(dev);
}
}
@@ -244,50 +245,44 @@
static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
{
- int status;
- struct netpoll_info *npinfo;
+ int status = NETDEV_TX_BUSY;
+ unsigned long tries;
+ struct net_device *dev = np->dev;
+ struct netpoll_info *npinfo = np->dev->npinfo;
- if (!np || !np->dev || !netif_running(np->dev)) {
- __kfree_skb(skb);
- return;
+ if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
+ __kfree_skb(skb);
+ return;
+ }
+
+ /* don't get messages out of order, and no recursion */
+ if ( !(np->drop == netpoll_queue && skb_queue_len(&npinfo->txq))
+ && 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);
+
+ if (status == NETDEV_TX_OK)
+ break;
+
+ /* tickle device maybe there is some cleanup */
+ netpoll_poll(np);
+
+ udelay(USEC_PER_POLL);
+ }
+ netif_tx_unlock(dev);
}
- npinfo = np->dev->npinfo;
-
- /* avoid recursion */
- if (npinfo->poll_owner == smp_processor_id() ||
- np->dev->xmit_lock_owner == smp_processor_id()) {
+ if (status != NETDEV_TX_OK) {
+ /* requeue for later */
if (np->drop)
np->drop(skb);
else
__kfree_skb(skb);
- return;
}
-
- do {
- npinfo->tries--;
- netif_tx_lock(np->dev);
-
- /*
- * network drivers do not expect to be called if the queue is
- * stopped.
- */
- status = NETDEV_TX_BUSY;
- if (!netif_queue_stopped(np->dev))
- status = np->dev->hard_start_xmit(skb, np->dev);
-
- netif_tx_unlock(np->dev);
-
- /* success */
- if(!status) {
- npinfo->tries = MAX_RETRIES; /* reset */
- return;
- }
-
- /* transmit busy */
- netpoll_poll(np);
- udelay(50);
- } while (npinfo->tries > 0);
}
void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
@@ -649,7 +644,7 @@
npinfo->rx_np = NULL;
spin_lock_init(&npinfo->poll_lock);
npinfo->poll_owner = -1;
- npinfo->tries = MAX_RETRIES;
+
spin_lock_init(&npinfo->rx_lock);
skb_queue_head_init(&npinfo->arp_tx);
skb_queue_head_init(&npinfo->txq);