Send of0 packets from workqueue, to avoid recursive locking of ofN device.

[sliver-openvswitch.git] / datapath / dp_dev.c

diff --git a/datapath/dp_dev.c b/datapath/dp_dev.c
index 4601852..7817d0d 100644 (file)
--- a/datapath/dp_dev.c
+++ b/datapath/dp_dev.c
@@ -3,6 +3,7 @@
 #include <linux/etherdevice.h>
 #include <linux/rcupdate.h>
 #include <linux/skbuff.h>
+#include <linux/workqueue.h>
 
 #include "datapath.h"
 #include "forward.h"
@@ -10,8 +11,11 @@
 struct dp_dev {
        struct net_device_stats stats;
        struct datapath *dp;
+       struct sk_buff_head xmit_queue;
+       struct work_struct xmit_work;
 };
 
+
 static struct dp_dev *dp_dev_priv(struct net_device *netdev) 
 {
        return netdev_priv(netdev);
@@ -60,14 +64,37 @@ static int dp_dev_xmit(struct sk_buff *skb, struct net_device *netdev)
        dp_dev->stats.tx_packets++;
        dp_dev->stats.tx_bytes += skb->len;
 
-       skb_reset_mac_header(skb);
-       rcu_read_lock();
-       fwd_port_input(dp->chain, skb, OFPP_LOCAL);
-       rcu_read_unlock();
+       if (skb_queue_len(&dp_dev->xmit_queue) >= dp->netdev->tx_queue_len) {
+               /* Queue overflow.  Stop transmitter. */
+               netif_stop_queue(dp->netdev);
+
+               /* We won't see all dropped packets individually, so overrun
+                * error is appropriate. */
+               dp_dev->stats.tx_fifo_errors++;
+       }
+       skb_queue_tail(&dp_dev->xmit_queue, skb);
+       dp->netdev->trans_start = jiffies;
+
+       schedule_work(&dp_dev->xmit_work);
 
        return 0;
 }
 
+static void dp_dev_do_xmit(struct work_struct *work)
+{
+       struct dp_dev *dp_dev = container_of(work, struct dp_dev, xmit_work);
+       struct datapath *dp = dp_dev->dp;
+       struct sk_buff *skb;
+
+       while ((skb = skb_dequeue(&dp_dev->xmit_queue)) != NULL) {
+               skb_reset_mac_header(skb);
+               rcu_read_lock();
+               fwd_port_input(dp->chain, skb, OFPP_LOCAL);
+               rcu_read_unlock();
+       }
+       netif_wake_queue(dp->netdev);
+}
+
 static int dp_dev_open(struct net_device *netdev)
 {
        netif_start_queue(netdev);
@@ -89,7 +116,7 @@ do_setup(struct net_device *netdev)
        netdev->hard_start_xmit = dp_dev_xmit;
        netdev->open = dp_dev_open;
        netdev->stop = dp_dev_stop;
-       netdev->tx_queue_len = 0;
+       netdev->tx_queue_len = 100;
        netdev->set_mac_address = dp_dev_mac_addr;
 
        netdev->flags = IFF_BROADCAST | IFF_MULTICAST;
@@ -121,14 +148,19 @@ int dp_dev_setup(struct datapath *dp)
 
        dp_dev = dp_dev_priv(netdev);
        dp_dev->dp = dp;
+       skb_queue_head_init(&dp_dev->xmit_queue);
+       INIT_WORK(&dp_dev->xmit_work, dp_dev_do_xmit);
        dp->netdev = netdev;
        return 0;
 }
 
 void dp_dev_destroy(struct datapath *dp)
 {
+       struct dp_dev *dp_dev = dp_dev_priv(dp->netdev);
+
        netif_tx_disable(dp->netdev);
        synchronize_net();
+       skb_queue_purge(&dp_dev->xmit_queue);
        unregister_netdev(dp->netdev);
        free_netdev(dp->netdev);
 }