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authorEric Dumazet <edumazet@google.com>2014-10-05 18:38:35 -0700
committerDavid S. Miller <davem@davemloft.net>2014-10-07 13:22:11 -0400
commit0287587884b15041203b3a362d485e1ab1f24445 (patch)
tree675ae57663c1ba3ee8768e65e7fb0e6d0259e04c /net/ipv6
parentfe971b95c22578456ff7198537827841c726d3f7 (diff)
net: better IFF_XMIT_DST_RELEASE support
Testing xmit_more support with netperf and connected UDP sockets, I found strange dst refcount false sharing. Current handling of IFF_XMIT_DST_RELEASE is not optimal. Dropping dst in validate_xmit_skb() is certainly too late in case packet was queued by cpu X but dequeued by cpu Y The logical point to take care of drop/force is in __dev_queue_xmit() before even taking qdisc lock. As Julian Anastasov pointed out, need for skb_dst() might come from some packet schedulers or classifiers. This patch adds new helper to cleanly express needs of various drivers or qdiscs/classifiers. Drivers that need skb_dst() in their ndo_start_xmit() should call following helper in their setup instead of the prior : dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; -> netif_keep_dst(dev); Instead of using a single bit, we use two bits, one being eventually rebuilt in bonding/team drivers. The other one, is permanent and blocks IFF_XMIT_DST_RELEASE being rebuilt in bonding/team. Eventually, we could add something smarter later. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/ip6_gre.c2
-rw-r--r--net/ipv6/ip6_tunnel.c2
-rw-r--r--net/ipv6/ip6_vti.c2
-rw-r--r--net/ipv6/sit.c2
4 files changed, 4 insertions, 4 deletions
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 74b677916a70..de3b1c86b8d3 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1242,7 +1242,7 @@ static void ip6gre_tunnel_setup(struct net_device *dev)
dev->flags |= IFF_NOARP;
dev->iflink = 0;
dev->addr_len = sizeof(struct in6_addr);
- dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
+ netif_keep_dst(dev);
}
static int ip6gre_tunnel_init(struct net_device *dev)
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index d3e8888ad611..9409887fb664 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1493,7 +1493,7 @@ static void ip6_tnl_dev_setup(struct net_device *dev)
dev->mtu -= 8;
dev->flags |= IFF_NOARP;
dev->addr_len = sizeof(struct in6_addr);
- dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
+ netif_keep_dst(dev);
/* This perm addr will be used as interface identifier by IPv6 */
dev->addr_assign_type = NET_ADDR_RANDOM;
eth_random_addr(dev->perm_addr);
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 5833a2244467..d440bb585524 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -807,7 +807,7 @@ static void vti6_dev_setup(struct net_device *dev)
dev->mtu = ETH_DATA_LEN;
dev->flags |= IFF_NOARP;
dev->addr_len = sizeof(struct in6_addr);
- dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
+ netif_keep_dst(dev);
}
/**
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 0d4e27466f82..6eab37cf5345 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -1364,7 +1364,7 @@ static void ipip6_tunnel_setup(struct net_device *dev)
dev->hard_header_len = LL_MAX_HEADER + t_hlen;
dev->mtu = ETH_DATA_LEN - t_hlen;
dev->flags = IFF_NOARP;
- dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
+ netif_keep_dst(dev);
dev->iflink = 0;
dev->addr_len = 4;
dev->features |= NETIF_F_LLTX;