net: add dst_cache to ovs vxlan lwtunnel

In case of UDP traffic with datagram length
below MTU this give about 2% performance increase
when tunneling over ipv4 and about 60% when tunneling
over ipv6

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>

3 files changed, 16 insertions, 1 deletions

diff --git a/net/core/dst.c b/net/core/dst.c
index a1656e3b8d72..b5cbbe07f786 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -265,7 +265,7 @@ again:
         lwtstate_put(dst->lwtstate);
 
         if (dst->flags & DST_METADATA)
-                kfree(dst);
+                metadata_dst_free((struct metadata_dst *)dst);
         else
                 kmem_cache_free(dst->ops->kmem_cachep, dst);
 
@@ -395,6 +395,14 @@ struct metadata_dst *metadata_dst_alloc(u8 optslen, gfp_t flags)
 }
 EXPORT_SYMBOL_GPL(metadata_dst_alloc);
 
+void metadata_dst_free(struct metadata_dst *md_dst)
+{
+#ifdef CONFIG_DST_CACHE
+        dst_cache_destroy(&md_dst->u.tun_info.dst_cache);
+#endif
+        kfree(md_dst);
+}
+
 struct metadata_dst __percpu *metadata_dst_alloc_percpu(u8 optslen, gfp_t flags)
 {
         int cpu;
diff --git a/net/openvswitch/Kconfig b/net/openvswitch/Kconfig
index d143aa9f6654..cd5fd9d728a7 100644
--- a/net/openvswitch/Kconfig
+++ b/net/openvswitch/Kconfig
@@ -10,6 +10,7 @@ config OPENVSWITCH
         select LIBCRC32C
         select MPLS
         select NET_MPLS_GSO
+        select DST_CACHE
         ---help---
           Open vSwitch is a multilayer Ethernet switch targeted at virtualized
           environments.  In addition to supporting a variety of features
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index d1bd4a45ca2d..58b8efc23668 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -1959,6 +1959,12 @@ static int validate_and_copy_set_tun(const struct nlattr *attr,
         if (!tun_dst)
                 return -ENOMEM;
 
+        err = dst_cache_init(&tun_dst->u.tun_info.dst_cache, GFP_KERNEL);
+        if (err) {
+                dst_release((struct dst_entry *)tun_dst);
+                return err;
+        }
+
         a = __add_action(sfa, OVS_KEY_ATTR_TUNNEL_INFO, NULL,
                          sizeof(*ovs_tun), log);
         if (IS_ERR(a)) {