diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2017-06-12 11:23:42 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-06-12 10:01:29 -0400 |
| commit | 0a463c78d25b9464b77311d9dda297550a2d6aa5 (patch) | |
| tree | 87152851619730150299fe4acf3a7a0eff8a6f4b /net/ipv4 | |
| parent | 3889a803e1da9bd7cd10d6504bf281ee7e55dfd6 (diff) | |
| download | linux-0a463c78d25b9464b77311d9dda297550a2d6aa5.tar.bz2 | |
udp: avoid a cache miss on dequeue
Since UDP no more uses sk->destructor, we can clear completely
the skb head state before enqueuing. Amend and use
skb_release_head_state() for that.
All head states share a single cacheline, which is not
normally used/accesses on dequeue. We can avoid entirely accessing
such cacheline implementing and using in the UDP code a specialized
skb free helper which ignores the skb head state.
This saves a cacheline miss at skb deallocation time.
v1 -> v2:
replaced secpath_reset() with skb_release_head_state()
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/udp.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index fdcb7437cc15..d8b265f1a33b 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1359,7 +1359,8 @@ void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) sk_peek_offset_bwd(sk, len); unlock_sock_fast(sk, slow); } - consume_skb(skb); + + consume_stateless_skb(skb); } EXPORT_SYMBOL_GPL(skb_consume_udp); @@ -1739,6 +1740,9 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) sk_mark_napi_id_once(sk, skb); } + /* clear all pending head states while they are hot in the cache */ + skb_release_head_state(skb); + rc = __udp_enqueue_schedule_skb(sk, skb); if (rc < 0) { int is_udplite = IS_UDPLITE(sk); |