diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-04-28 00:13:20 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-04-28 00:13:20 +0200 |
| commit | c377411f2494a931ff7facdbb3a6839b1266bcf6 (patch) | |
| tree | 6846cdcec913f50839e3916856f78f7e059ff5fb /net/core | |
| parent | net: batch skb dequeueing from softnet input_pkt_queue (diff) | |
| download | linux-c377411f2494a931ff7facdbb3a6839b1266bcf6.tar.xz linux-c377411f2494a931ff7facdbb3a6839b1266bcf6.zip | |
net: sk_add_backlog() take rmem_alloc into account
Current socket backlog limit is not enough to really stop DDOS attacks,
because user thread spend many time to process a full backlog each
round, and user might crazy spin on socket lock.
We should add backlog size and receive_queue size (aka rmem_alloc) to
pace writers, and let user run without being slow down too much.
Introduce a sk_rcvqueues_full() helper, to avoid taking socket lock in
stress situations.
Under huge stress from a multiqueue/RPS enabled NIC, a single flow udp
receiver can now process ~200.000 pps (instead of ~100 pps before the
patch) on a 8 core machine.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/sock.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index 58ebd146ce5a..51041759517e 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -327,6 +327,10 @@ int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested) skb->dev = NULL; + if (sk_rcvqueues_full(sk, skb)) { + atomic_inc(&sk->sk_drops); + goto discard_and_relse; + } if (nested) bh_lock_sock_nested(sk); else @@ -1885,7 +1889,6 @@ void sock_init_data(struct socket *sock, struct sock *sk) sk->sk_allocation = GFP_KERNEL; sk->sk_rcvbuf = sysctl_rmem_default; sk->sk_sndbuf = sysctl_wmem_default; - sk->sk_backlog.limit = sk->sk_rcvbuf << 1; sk->sk_state = TCP_CLOSE; sk_set_socket(sk, sock); |