Revert "datapath: Don't orphan packets in dp_dev transmit path."

This reverts commit 0858ad2b9d2f594f99bb11fc9b331ce8b1de953d.
Although that commit partially fixed a performance regression
relative to the Linux bridge, it introduced other problems that
were not apparent in the performance testing (e.g.
WARN_ON_ONCE(skb->destructor) now triggers in dp_process_received_packet()).
The fix is not completely obvious, so reverting now to ensure stability
while investigating the problem.

diff --git a/datapath/dp_dev.c b/datapath/dp_dev.c
index 3902a8c..5aa32f0 100644 (file)
--- a/datapath/dp_dev.c
+++ b/datapath/dp_dev.c
@@ -86,6 +86,12 @@ static int dp_dev_xmit(struct sk_buff *skb, struct net_device *netdev)
        struct dp_dev *dp_dev = dp_dev_priv(netdev);
        struct pcpu_lstats *lb_stats;
 
+       /* By orphaning 'skb' we will screw up socket accounting slightly, but
+        * the effect is limited to the device queue length.  If we don't
+        * do this, then the sk_buff will be destructed eventually, but it is
+        * harder to predict when. */
+       skb_orphan(skb);
+
        /* dp_process_received_packet() needs its own clone. */
        skb = skb_share_check(skb, GFP_ATOMIC);
        if (!skb)