tcp: move tcp_update_cwnd_in_recovery
To prepare replacing rate halving with PRR algorithm in CWR state.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3ab0c75..38589e4 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2700,6 +2700,38 @@
return false;
}
+/* This function implements the PRR algorithm, specifcally the PRR-SSRB
+ * (proportional rate reduction with slow start reduction bound) as described in
+ * http://www.ietf.org/id/draft-mathis-tcpm-proportional-rate-reduction-01.txt.
+ * It computes the number of packets to send (sndcnt) based on packets newly
+ * delivered:
+ * 1) If the packets in flight is larger than ssthresh, PRR spreads the
+ * cwnd reductions across a full RTT.
+ * 2) If packets in flight is lower than ssthresh (such as due to excess
+ * losses and/or application stalls), do not perform any further cwnd
+ * reductions, but instead slow start up to ssthresh.
+ */
+static void tcp_update_cwnd_in_recovery(struct sock *sk, int newly_acked_sacked,
+ int fast_rexmit, int flag)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ int sndcnt = 0;
+ int delta = tp->snd_ssthresh - tcp_packets_in_flight(tp);
+
+ if (tcp_packets_in_flight(tp) > tp->snd_ssthresh) {
+ u64 dividend = (u64)tp->snd_ssthresh * tp->prr_delivered +
+ tp->prior_cwnd - 1;
+ sndcnt = div_u64(dividend, tp->prior_cwnd) - tp->prr_out;
+ } else {
+ sndcnt = min_t(int, delta,
+ max_t(int, tp->prr_delivered - tp->prr_out,
+ newly_acked_sacked) + 1);
+ }
+
+ sndcnt = max(sndcnt, (fast_rexmit ? 1 : 0));
+ tp->snd_cwnd = tcp_packets_in_flight(tp) + sndcnt;
+}
+
static inline void tcp_complete_cwr(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
@@ -2854,38 +2886,6 @@
}
EXPORT_SYMBOL(tcp_simple_retransmit);
-/* This function implements the PRR algorithm, specifcally the PRR-SSRB
- * (proportional rate reduction with slow start reduction bound) as described in
- * http://www.ietf.org/id/draft-mathis-tcpm-proportional-rate-reduction-01.txt.
- * It computes the number of packets to send (sndcnt) based on packets newly
- * delivered:
- * 1) If the packets in flight is larger than ssthresh, PRR spreads the
- * cwnd reductions across a full RTT.
- * 2) If packets in flight is lower than ssthresh (such as due to excess
- * losses and/or application stalls), do not perform any further cwnd
- * reductions, but instead slow start up to ssthresh.
- */
-static void tcp_update_cwnd_in_recovery(struct sock *sk, int newly_acked_sacked,
- int fast_rexmit, int flag)
-{
- struct tcp_sock *tp = tcp_sk(sk);
- int sndcnt = 0;
- int delta = tp->snd_ssthresh - tcp_packets_in_flight(tp);
-
- if (tcp_packets_in_flight(tp) > tp->snd_ssthresh) {
- u64 dividend = (u64)tp->snd_ssthresh * tp->prr_delivered +
- tp->prior_cwnd - 1;
- sndcnt = div_u64(dividend, tp->prior_cwnd) - tp->prr_out;
- } else {
- sndcnt = min_t(int, delta,
- max_t(int, tp->prr_delivered - tp->prr_out,
- newly_acked_sacked) + 1);
- }
-
- sndcnt = max(sndcnt, (fast_rexmit ? 1 : 0));
- tp->snd_cwnd = tcp_packets_in_flight(tp) + sndcnt;
-}
-
static void tcp_enter_recovery(struct sock *sk, bool ece_ack)
{
struct tcp_sock *tp = tcp_sk(sk);