path: root/net/ipv4/udp_diag.c
diff options
authorEric Dumazet <edumazet@google.com>2016-04-01 08:52:13 -0700
committerDavid S. Miller <davem@davemloft.net>2016-04-04 22:11:19 -0400
commitca065d0cf80fa547724440a8bf37f1e674d917c0 (patch)
tree6384df2fda5ff249da39464de7e7b9a079a794e6 /net/ipv4/udp_diag.c
parentnet: add SOCK_RCU_FREE socket flag (diff)
udp: no longer use SLAB_DESTROY_BY_RCU
Tom Herbert would like not touching UDP socket refcnt for encapsulated traffic. For this to happen, we need to use normal RCU rules, with a grace period before freeing a socket. UDP sockets are not short lived in the high usage case, so the added cost of call_rcu() should not be a concern. This actually removes a lot of complexity in UDP stack. Multicast receives no longer need to hold a bucket spinlock. Note that ip early demux still needs to take a reference on the socket. Same remark for functions used by xt_socket and xt_PROXY netfilter modules, but this might be changed later. Performance for a single UDP socket receiving flood traffic from many RX queues/cpus. Simple udp_rx using simple recvfrom() loop : 438 kpps instead of 374 kpps : 17 % increase of the peak rate. v2: Addressed Willem de Bruijn feedback in multicast handling - keep early demux break in __udp4_lib_demux_lookup() Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <tom@herbertland.com> Cc: Willem de Bruijn <willemb@google.com> Tested-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 9 insertions, 9 deletions
diff --git a/net/ipv4/udp_diag.c b/net/ipv4/udp_diag.c
index df1966f3b6ec..3d5ccf4b1412 100644
--- a/net/ipv4/udp_diag.c
+++ b/net/ipv4/udp_diag.c
@@ -36,10 +36,11 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
const struct inet_diag_req_v2 *req)
int err = -EINVAL;
- struct sock *sk;
+ struct sock *sk = NULL;
struct sk_buff *rep;
struct net *net = sock_net(in_skb->sk);
+ rcu_read_lock();
if (req->sdiag_family == AF_INET)
sk = __udp4_lib_lookup(net,
req->id.idiag_src[0], req->id.idiag_sport,
@@ -54,9 +55,9 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
req->id.idiag_if, tbl, NULL);
- else
- goto out_nosk;
+ if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
+ sk = NULL;
+ rcu_read_unlock();
err = -ENOENT;
if (!sk)
goto out_nosk;
@@ -96,24 +97,23 @@ static void udp_dump(struct udp_table *table, struct sk_buff *skb,
struct netlink_callback *cb,
const struct inet_diag_req_v2 *r, struct nlattr *bc)
- int num, s_num, slot, s_slot;
struct net *net = sock_net(skb->sk);
+ int num, s_num, slot, s_slot;
s_slot = cb->args[0];
num = s_num = cb->args[1];
for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
- struct sock *sk;
- struct hlist_nulls_node *node;
struct udp_hslot *hslot = &table->hash[slot];
+ struct sock *sk;
num = 0;
- if (hlist_nulls_empty(&hslot->head))
+ if (hlist_empty(&hslot->head))
- sk_nulls_for_each(sk, node, &hslot->head) {
+ sk_for_each(sk, &hslot->head) {
struct inet_sock *inet = inet_sk(sk);
if (!net_eq(sock_net(sk), net))