diff options
| author | Florian Westphal <fw@strlen.de> | 2014-09-26 22:37:34 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-09-29 00:13:10 -0400 |
| commit | 7354c8c389d18719dd71cc810da70b0921d66694 (patch) | |
| tree | 776fa6ce824557d0c8bbf4271ad3b08a4832a66f /net/ipv4/tcp_input.c | |
| parent | 30e502a34b8b21fae2c789da102bd9f6e99fef83 (diff) | |
| download | lwn-7354c8c389d18719dd71cc810da70b0921d66694.tar.gz lwn-7354c8c389d18719dd71cc810da70b0921d66694.zip | |
net: tcp: split ack slow/fast events from cwnd_event
The congestion control ops "cwnd_event" currently supports
CA_EVENT_FAST_ACK and CA_EVENT_SLOW_ACK events (among others).
Both FAST and SLOW_ACK are only used by Westwood congestion
control algorithm.
This removes both flags from cwnd_event and adds a new
in_ack_event callback for this. The goal is to be able to
provide more detailed information about ACKs, such as whether
ECE flag was set, or whether the ACK resulted in a window
update.
It is required for DataCenter TCP (DCTCP) congestion control
algorithm as it makes a different choice depending on ECE being
set or not.
Joint work with Daniel Borkmann and Glenn Judd.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
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 | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index fb0fe97e1c54..8a38774cc66e 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3362,6 +3362,14 @@ static void tcp_process_tlp_ack(struct sock *sk, u32 ack, int flag) } } +static inline void tcp_in_ack_event(struct sock *sk, u32 flags) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + if (icsk->icsk_ca_ops->in_ack_event) + icsk->icsk_ca_ops->in_ack_event(sk, flags); +} + /* This routine deals with incoming acks, but not outgoing ones. */ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) { @@ -3421,7 +3429,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) tp->snd_una = ack; flag |= FLAG_WIN_UPDATE; - tcp_ca_event(sk, CA_EVENT_FAST_ACK); + tcp_in_ack_event(sk, 0); NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPHPACKS); } else { @@ -3439,7 +3447,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) if (TCP_ECN_rcv_ecn_echo(tp, tcp_hdr(skb))) flag |= FLAG_ECE; - tcp_ca_event(sk, CA_EVENT_SLOW_ACK); + tcp_in_ack_event(sk, CA_ACK_SLOWPATH); } /* We passed data and got it acked, remove any soft error |