On Thu, 11 Feb 2016 11:12:01 +0100, Paolo Abeni wrote:
> In case of UDP traffic with datagram length
> below MTU this give about 2% performance increase
The performance increase is not that great probably because of the
addition of the pointer to ip_tunnel_info, making it even fatter than
it is now.
> diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
> index d1bd4a4..f181186 100644
> --- a/net/openvswitch/flow_netlink.c
> +++ b/net/openvswitch/flow_netlink.c
> @@ -1698,6 +1698,7 @@ static void ovs_nla_free_set_action(const struct nlattr
> *a)
> case OVS_KEY_ATTR_TUNNEL_INFO:
> ovs_tun = nla_data(ovs_key);
> dst_release((struct dst_entry *)ovs_tun->tun_dst);
> + dst_cache_destroy(&ovs_tun->dst_cache);
We need a helper function for this, operating on ovs_tunnel_info.
> break;
> }
> }
> @@ -1928,6 +1929,7 @@ static int validate_and_copy_set_tun(const struct
> nlattr *attr,
> {
> struct sw_flow_match match;
> struct sw_flow_key key;
> + struct dst_cache dst_cache;
> struct metadata_dst *tun_dst;
> struct ip_tunnel_info *tun_info;
> struct ovs_tunnel_info *ovs_tun;
> @@ -1959,15 +1961,24 @@ static int validate_and_copy_set_tun(const struct
> nlattr *attr,
> if (!tun_dst)
> return -ENOMEM;
>
> + err = dst_cache_init(&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)) {
> dst_release((struct dst_entry *)tun_dst);
> + dst_cache_destroy(&dst_cache);
Make the local variable be of ovs_tunnel_info type and use the helper
function here.
> return PTR_ERR(a);
> }
>
> ovs_tun = nla_data(a);
> ovs_tun->tun_dst = tun_dst;
> + ovs_tun->dst_cache = dst_cache;
Why are you copying the data here? The cache should be initialized in
place in ovs_tun.
> + tun_dst->u.tun_info.dst_cache = &ovs_tun->dst_cache;
The absence of reference counting here will lead to use after free when
processing a packet referencing tun_dst while the corresponding
dst_cache memory is freed on flow deletion. Note that tun_dst is
reference counted (see execute_set_action).
Jiri
--
Jiri Benc
