tunnel: eliminate recursion field

It seems recursion field from "struct ip_tunnel" is not anymore needed.
recursion prevention is done at the upper level (in dev_queue_xmit()),
since we use HARD_TX_LOCK protection for tunnels.

This avoids a cache line ping pong on "struct ip_tunnel" : This structure
should be now mostly read on xmit and receive paths.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 0 insertions, 15 deletions

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 7d25bbe..c595bbe 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1043,11 +1043,6 @@ ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct net_device_stats *stats = &t->dev->stats;
 	int ret;
 
-	if (t->recursion++) {
-		stats->collisions++;
-		goto tx_err;
-	}
-
 	switch (skb->protocol) {
 	case htons(ETH_P_IP):
 		ret = ip4ip6_tnl_xmit(skb, dev);
@@ -1062,14 +1057,12 @@ ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (ret < 0)
 		goto tx_err;
 
-	t->recursion--;
 	return NETDEV_TX_OK;
 
 tx_err:
 	stats->tx_errors++;
 	stats->tx_dropped++;
 	kfree_skb(skb);
-	t->recursion--;
 	return NETDEV_TX_OK;
 }
 
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 0ae4f64..fcb5396 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -626,11 +626,6 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 	struct in6_addr *addr6;
 	int addr_type;
 
-	if (tunnel->recursion++) {
-		stats->collisions++;
-		goto tx_error;
-	}
-
 	if (skb->protocol != htons(ETH_P_IPV6))
 		goto tx_error;
 
@@ -753,7 +748,6 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 			ip_rt_put(rt);
 			stats->tx_dropped++;
 			dev_kfree_skb(skb);
-			tunnel->recursion--;
 			return NETDEV_TX_OK;
 		}
 		if (skb->sk)
@@ -794,7 +788,6 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 	nf_reset(skb);
 
 	IPTUNNEL_XMIT();
-	tunnel->recursion--;
 	return NETDEV_TX_OK;
 
 tx_error_icmp:
@@ -802,7 +795,6 @@ tx_error_icmp:
 tx_error:
 	stats->tx_errors++;
 	dev_kfree_skb(skb);
-	tunnel->recursion--;
 	return NETDEV_TX_OK;
 }