geneve: add dst caching support

use generic dst implementation for both plain geneve devices and
lwtunnels.

In case of UDP traffic with datagram length below MTU this give
about 2% performance increase for plain geneve tunnel over ipv4,
about 65% performance increase for ipv6 tunnel.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Suggested-and-Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 0b14ac3..6f20813 100644 (file)
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -72,6 +72,7 @@ struct geneve_dev {
        bool               collect_md;
        struct gro_cells   gro_cells;
        u32                flags;
+       struct dst_cache   dst_cache;
 };
 
 /* Geneve device flags */
@@ -297,6 +298,13 @@ static int geneve_init(struct net_device *dev)
                return err;
        }
 
+       err = dst_cache_init(&geneve->dst_cache, GFP_KERNEL);
+       if (err) {
+               free_percpu(dev->tstats);
+               gro_cells_destroy(&geneve->gro_cells);
+               return err;
+       }
+
        return 0;
 }
 
@@ -304,6 +312,7 @@ static void geneve_uninit(struct net_device *dev)
 {
        struct geneve_dev *geneve = netdev_priv(dev);
 
+       dst_cache_destroy(&geneve->dst_cache);
        gro_cells_destroy(&geneve->gro_cells);
        free_percpu(dev->tstats);
 }
@@ -753,7 +762,9 @@ static struct rtable *geneve_get_v4_rt(struct sk_buff *skb,
                                       struct ip_tunnel_info *info)
 {
        struct geneve_dev *geneve = netdev_priv(dev);
+       struct dst_cache *dst_cache;
        struct rtable *rt = NULL;
+       bool use_cache = true;
        __u8 tos;
 
        memset(fl4, 0, sizeof(*fl4));
@@ -764,16 +775,26 @@ static struct rtable *geneve_get_v4_rt(struct sk_buff *skb,
                fl4->daddr = info->key.u.ipv4.dst;
                fl4->saddr = info->key.u.ipv4.src;
                fl4->flowi4_tos = RT_TOS(info->key.tos);
+               dst_cache = &info->dst_cache;
        } else {
                tos = geneve->tos;
                if (tos == 1) {
                        const struct iphdr *iip = ip_hdr(skb);
 
                        tos = ip_tunnel_get_dsfield(iip, skb);
+                       use_cache = false;
                }
 
                fl4->flowi4_tos = RT_TOS(tos);
                fl4->daddr = geneve->remote.sin.sin_addr.s_addr;
+               dst_cache = &geneve->dst_cache;
+       }
+
+       use_cache = use_cache && !skb->mark;
+       if (use_cache) {
+               rt = dst_cache_get_ip4(dst_cache, &fl4->saddr);
+               if (rt)
+                       return rt;
        }
 
        rt = ip_route_output_key(geneve->net, fl4);
@@ -786,6 +807,8 @@ static struct rtable *geneve_get_v4_rt(struct sk_buff *skb,
                ip_rt_put(rt);
                return ERR_PTR(-ELOOP);
        }
+       if (use_cache)
+               dst_cache_set_ip4(dst_cache, &rt->dst, fl4->saddr);
        return rt;
 }
 
@@ -798,6 +821,8 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
        struct geneve_dev *geneve = netdev_priv(dev);
        struct geneve_sock *gs6 = geneve->sock6;
        struct dst_entry *dst = NULL;
+       struct dst_cache *dst_cache;
+       bool use_cache = true;
        __u8 prio;
 
        memset(fl6, 0, sizeof(*fl6));
@@ -808,16 +833,26 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
                fl6->daddr = info->key.u.ipv6.dst;
                fl6->saddr = info->key.u.ipv6.src;
                fl6->flowi6_tos = RT_TOS(info->key.tos);
+               dst_cache = &info->dst_cache;
        } else {
                prio = geneve->tos;
                if (prio == 1) {
                        const struct iphdr *iip = ip_hdr(skb);
 
                        prio = ip_tunnel_get_dsfield(iip, skb);
+                       use_cache = false;
                }
 
                fl6->flowi6_tos = RT_TOS(prio);
                fl6->daddr = geneve->remote.sin6.sin6_addr;
+               dst_cache = &geneve->dst_cache;
+       }
+
+       use_cache = use_cache && !skb->mark;
+       if (use_cache) {
+               dst = dst_cache_get_ip6(dst_cache, &fl6->saddr);
+               if (dst)
+                       return dst;
        }
 
        if (ipv6_stub->ipv6_dst_lookup(geneve->net, gs6->sock->sk, &dst, fl6)) {
@@ -830,6 +865,8 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
                return ERR_PTR(-ELOOP);
        }
 
+       if (use_cache)
+               dst_cache_set_ip6(dst_cache, dst, &fl6->saddr);
        return dst;
 }
 #endif
@@ -1272,6 +1309,8 @@ static int geneve_configure(struct net *net, struct net_device *dev,
                        return -EPERM;
        }
 
+       dst_cache_reset(&geneve->dst_cache);
+
        err = register_netdevice(dev);
        if (err)
                return err;