tcp: Revert "tcp: remove CA_ACK_SLOWPATH"
This change was a followup to the header prediction removal,
so first revert this as a prerequisite to back out hp removal.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c
index e5de843..bec9caf 100644
--- a/net/ipv4/tcp_westwood.c
+++ b/net/ipv4/tcp_westwood.c
@@ -154,6 +154,24 @@ static inline void update_rtt_min(struct westwood *w)
}
/*
+ * @westwood_fast_bw
+ * It is called when we are in fast path. In particular it is called when
+ * header prediction is successful. In such case in fact update is
+ * straight forward and doesn't need any particular care.
+ */
+static inline void westwood_fast_bw(struct sock *sk)
+{
+ const struct tcp_sock *tp = tcp_sk(sk);
+ struct westwood *w = inet_csk_ca(sk);
+
+ westwood_update_window(sk);
+
+ w->bk += tp->snd_una - w->snd_una;
+ w->snd_una = tp->snd_una;
+ update_rtt_min(w);
+}
+
+/*
* @westwood_acked_count
* This function evaluates cumul_ack for evaluating bk in case of
* delayed or partial acks.
@@ -205,12 +223,17 @@ static u32 tcp_westwood_bw_rttmin(const struct sock *sk)
static void tcp_westwood_ack(struct sock *sk, u32 ack_flags)
{
- struct westwood *w = inet_csk_ca(sk);
+ if (ack_flags & CA_ACK_SLOWPATH) {
+ struct westwood *w = inet_csk_ca(sk);
- westwood_update_window(sk);
- w->bk += westwood_acked_count(sk);
+ westwood_update_window(sk);
+ w->bk += westwood_acked_count(sk);
- update_rtt_min(w);
+ update_rtt_min(w);
+ return;
+ }
+
+ westwood_fast_bw(sk);
}
static void tcp_westwood_event(struct sock *sk, enum tcp_ca_event event)