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| author |   David S. Miller <davem@davemloft.net> | 2016-04-15 16:45:45 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-15 16:45:45 -0400 |
| commit | 125c8d1233b7dd4688f14dd992d724c20d055dee (patch) | |
| tree | fd1010fca7c152ca547f02d80a02dc9d1b9d7b20 /net/ipv4/tcp_input.c | |
| parent | qlge: Replace create_singlethread_workqueue with alloc_ordered_workqueue (diff) | |
| parent | tcp: remove false sharing in tcp_rcv_state_process() (diff) | |
| download | linux-dev-125c8d1233b7dd4688f14dd992d724c20d055dee.tar.xz linux-dev-125c8d1233b7dd4688f14dd992d724c20d055dee.zip | |
Merge branch 'tcp-synflood-perf'
Eric Dumazet says:
====================
tcp: final work on SYNFLOOD behavior
In the first patch, I remove the costly association of SYNACK+COOKIES
to a listener. I believe other parts of the stack should be ready.
The second patch removes a useless write into listener socket
in tcp_rcv_state_process(), incurring false sharing in
tcp_conn_request()
Performance under SYNFLOOD goes from 3.2 Mpps to 6 Mpps.
Test was using a single TCP listener, on a host with 8 RX queues
on the NIC, and 24 cores (48 ht)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 983f04c11177..90e0d9256b74 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5796,8 +5796,6 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) int queued = 0; bool acceptable; - tp->rx_opt.saw_tstamp = 0; - switch (sk->sk_state) { case TCP_CLOSE: goto discard; @@ -5838,6 +5836,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) goto discard; case TCP_SYN_SENT: + tp->rx_opt.saw_tstamp = 0; queued = tcp_rcv_synsent_state_process(sk, skb, th); if (queued >= 0) return queued; @@ -5849,6 +5848,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) return 0; } + tp->rx_opt.saw_tstamp = 0; req = tp->fastopen_rsk; if (req) { WARN_ON_ONCE(sk->sk_state != TCP_SYN_RECV && @@ -6327,7 +6327,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, } if (fastopen_sk) { af_ops->send_synack(fastopen_sk, dst, &fl, req, - &foc, false); + &foc, TCP_SYNACK_FASTOPEN); /* Add the child socket directly into the accept queue */ inet_csk_reqsk_queue_add(sk, req, fastopen_sk); sk->sk_data_ready(sk); @@ -6337,8 +6337,9 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, tcp_rsk(req)->tfo_listener = false; if (!want_cookie) inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); - af_ops->send_synack(sk, dst, &fl, req, - &foc, !want_cookie); + af_ops->send_synack(sk, dst, &fl, req, &foc, + !want_cookie ? TCP_SYNACK_NORMAL : + TCP_SYNACK_COOKIE); if (want_cookie) { reqsk_free(req); return 0; |