From: Eric Dumazet Date: Wed, 23 Sep 2009 10:28:33 +0000 (+0000) Subject: tunnel: eliminate recursion field X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a43912ab1925788765208da5cd664b6f8e011d08;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git 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 Signed-off-by: David S. Miller --- diff --git a/include/net/ipip.h b/include/net/ipip.h index 5d3036fa1511..76e3ea6e2fe5 100644 --- a/include/net/ipip.h +++ b/include/net/ipip.h @@ -12,7 +12,6 @@ struct ip_tunnel struct ip_tunnel *next; struct net_device *dev; - int recursion; /* Depth of hard_start_xmit recursion */ int err_count; /* Number of arrived ICMP errors */ unsigned long err_time; /* Time when the last ICMP error arrived */ diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index d9645c94a067..41ada9904d31 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 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev __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 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev ip_rt_put(rt); stats->tx_dropped++; dev_kfree_skb(skb); - tunnel->recursion--; return NETDEV_TX_OK; } if (skb->sk) @@ -888,7 +879,6 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev nf_reset(skb); IPTUNNEL_XMIT(); - tunnel->recursion--; return NETDEV_TX_OK; tx_error_icmp: @@ -897,7 +887,6 @@ tx_error_icmp: tx_error: stats->tx_errors++; dev_kfree_skb(skb); - tunnel->recursion--; return NETDEV_TX_OK; } diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c index 62548cb0923c..08ccd344de7a 100644 --- a/net/ipv4/ipip.c +++ b/net/ipv4/ipip.c @@ -402,11 +402,6 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) __be32 dst = tiph->daddr; int mtu; - if (tunnel->recursion++) { - stats->collisions++; - goto tx_error; - } - if (skb->protocol != htons(ETH_P_IP)) goto tx_error; @@ -485,7 +480,6 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) ip_rt_put(rt); stats->tx_dropped++; dev_kfree_skb(skb); - tunnel->recursion--; return NETDEV_TX_OK; } if (skb->sk) @@ -523,7 +517,6 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) nf_reset(skb); IPTUNNEL_XMIT(); - tunnel->recursion--; return NETDEV_TX_OK; tx_error_icmp: @@ -531,7 +524,6 @@ tx_error_icmp: tx_error: stats->tx_errors++; dev_kfree_skb(skb); - tunnel->recursion--; return NETDEV_TX_OK; } diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 7d25bbe32110..c595bbe1ed99 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 0ae4f6448187..fcb539628847 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; }