Merge branch 'unified-tunnel-dst-caching'

Paolo Abeni says:

====================
net: unify dst caching for tunnel devices

This patch series try to unify the dst cache implementations currently
present in the kernel, namely in ip_tunnel.c and ip6_tunnel.c, introducing a
new generic implementation, replacing the existing ones, and then using
the new implementation in other tunnel devices which currently lack it.

The new dst implementation is compiled, as built-in, only if any device using
it is enabled.

Caching the dst for the tunnel remote address gives small, but measurable,
performance improvement when tunneling over ipv4 (in the 2%-4% range) and
significant ones when tunneling over ipv6 (roughly 60% when no
fragmentation/segmentation take place and the tunnel local address
is not specified).

v2:
- move the vxlan dst_cache usage inside the device lookup functions
- fix usage after free for lwt tunnel moving the dst cache storage inside
  the dst_metadata,
- sparse codying style cleanup
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 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;