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>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index d9645c9..41ada99 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -66,10 +66,7 @@
solution, but it supposes maintaing new variable in ALL
skb, even if no tunneling is used.
- Current solution: t->recursion lock breaks dead loops. It looks
- like dev->tbusy flag, but I preferred new variable, because
- the semantics is different. One day, when hard_start_xmit
- will be multithreaded we will have to use skb->encapsulation.
+ Current solution: HARD_TX_LOCK lock breaks dead loops.
@@ -678,11 +675,6 @@
__be32 dst;
int mtu;
- if (tunnel->recursion++) {
- stats->collisions++;
- goto tx_error;
- }
-
if (dev->type == ARPHRD_ETHER)
IPCB(skb)->flags = 0;
@@ -820,7 +812,6 @@
ip_rt_put(rt);
stats->tx_dropped++;
dev_kfree_skb(skb);
- tunnel->recursion--;
return NETDEV_TX_OK;
}
if (skb->sk)
@@ -888,7 +879,6 @@
nf_reset(skb);
IPTUNNEL_XMIT();
- tunnel->recursion--;
return NETDEV_TX_OK;
tx_error_icmp:
@@ -897,7 +887,6 @@
tx_error:
stats->tx_errors++;
dev_kfree_skb(skb);
- tunnel->recursion--;
return NETDEV_TX_OK;
}