tcp: remove unused min_cwnd member of tcp_congestion_ops

Commit 684bad110757 "tcp: use PRR to reduce cwin in CWR state" removed all
calls to min_cwnd, so we can safely remove it.
Also, remove tcp_reno_min_cwnd because it was only used for min_cwnd.

Signed-off-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/networking/tcp.txt b/Documentation/networking/tcp.txt
index 7d11bb5..bdc4c0d 100644 (file)
--- a/Documentation/networking/tcp.txt
+++ b/Documentation/networking/tcp.txt
@@ -30,7 +30,7 @@ A congestion control mechanism can be registered through functions in
 tcp_cong.c. The functions used by the congestion control mechanism are
 registered via passing a tcp_congestion_ops struct to
 tcp_register_congestion_control. As a minimum name, ssthresh,
-cong_avoid, min_cwnd must be valid.
+cong_avoid must be valid.
 
 Private data for a congestion control mechanism is stored in tp->ca_priv.
 tcp_ca(tp) returns a pointer to this space.  This is preallocated space - it

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 56fc366..1f82053 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -791,8 +791,6 @@ struct tcp_congestion_ops {
 
        /* return slow start threshold (required) */
        u32 (*ssthresh)(struct sock *sk);
-       /* lower bound for congestion window (optional) */
-       u32 (*min_cwnd)(const struct sock *sk);
        /* do new cwnd calculation (required) */
        void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked, u32 in_flight);
        /* call before changing ca_state (optional) */
@@ -827,7 +825,6 @@ void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w);
 extern struct tcp_congestion_ops tcp_init_congestion_ops;
 u32 tcp_reno_ssthresh(struct sock *sk);
 void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked, u32 in_flight);
-u32 tcp_reno_min_cwnd(const struct sock *sk);
 extern struct tcp_congestion_ops tcp_reno;
 
 static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state)

diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index ad37bf1..f49351e 100644 (file)
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -362,21 +362,12 @@ u32 tcp_reno_ssthresh(struct sock *sk)
 }
 EXPORT_SYMBOL_GPL(tcp_reno_ssthresh);
 
-/* Lower bound on congestion window with halving. */
-u32 tcp_reno_min_cwnd(const struct sock *sk)
-{
-       const struct tcp_sock *tp = tcp_sk(sk);
-       return tp->snd_ssthresh/2;
-}
-EXPORT_SYMBOL_GPL(tcp_reno_min_cwnd);
-
 struct tcp_congestion_ops tcp_reno = {
        .flags          = TCP_CONG_NON_RESTRICTED,
        .name           = "reno",
        .owner          = THIS_MODULE,
        .ssthresh       = tcp_reno_ssthresh,
        .cong_avoid     = tcp_reno_cong_avoid,
-       .min_cwnd       = tcp_reno_min_cwnd,
 };
 
 /* Initial congestion control used (until SYN)
@@ -388,6 +379,5 @@ struct tcp_congestion_ops tcp_init_congestion_ops  = {
        .owner          = THIS_MODULE,
        .ssthresh       = tcp_reno_ssthresh,
        .cong_avoid     = tcp_reno_cong_avoid,
-       .min_cwnd       = tcp_reno_min_cwnd,
 };
 EXPORT_SYMBOL_GPL(tcp_init_congestion_ops);

diff --git a/net/ipv4/tcp_highspeed.c b/net/ipv4/tcp_highspeed.c
index 8ed9305..8b9e7ba 100644 (file)
--- a/net/ipv4/tcp_highspeed.c
+++ b/net/ipv4/tcp_highspeed.c
@@ -162,7 +162,6 @@ static struct tcp_congestion_ops tcp_highspeed __read_mostly = {
        .init           = hstcp_init,
        .ssthresh       = hstcp_ssthresh,
        .cong_avoid     = hstcp_cong_avoid,
-       .min_cwnd       = tcp_reno_min_cwnd,
 
        .owner          = THIS_MODULE,
        .name           = "highspeed"

diff --git a/net/ipv4/tcp_hybla.c b/net/ipv4/tcp_hybla.c
index 478fe82..2a1a9e2 100644 (file)
--- a/net/ipv4/tcp_hybla.c
+++ b/net/ipv4/tcp_hybla.c
@@ -166,7 +166,6 @@ static void hybla_cong_avoid(struct sock *sk, u32 ack, u32 acked,
 static struct tcp_congestion_ops tcp_hybla __read_mostly = {
        .init           = hybla_init,
        .ssthresh       = tcp_reno_ssthresh,
-       .min_cwnd       = tcp_reno_min_cwnd,
        .cong_avoid     = hybla_cong_avoid,
        .set_state      = hybla_state,
 

diff --git a/net/ipv4/tcp_illinois.c b/net/ipv4/tcp_illinois.c
index e498a62..be047c6 100644 (file)
--- a/net/ipv4/tcp_illinois.c
+++ b/net/ipv4/tcp_illinois.c
@@ -328,7 +328,6 @@ static struct tcp_congestion_ops tcp_illinois __read_mostly = {
        .flags          = TCP_CONG_RTT_STAMP,
        .init           = tcp_illinois_init,
        .ssthresh       = tcp_illinois_ssthresh,
-       .min_cwnd       = tcp_reno_min_cwnd,
        .cong_avoid     = tcp_illinois_cong_avoid,
        .set_state      = tcp_illinois_state,
        .get_info       = tcp_illinois_info,

diff --git a/net/ipv4/tcp_lp.c b/net/ipv4/tcp_lp.c
index 991d62a..503798f 100644 (file)
--- a/net/ipv4/tcp_lp.c
+++ b/net/ipv4/tcp_lp.c
@@ -319,7 +319,6 @@ static struct tcp_congestion_ops tcp_lp __read_mostly = {
        .init = tcp_lp_init,
        .ssthresh = tcp_reno_ssthresh,
        .cong_avoid = tcp_lp_cong_avoid,
-       .min_cwnd = tcp_reno_min_cwnd,
        .pkts_acked = tcp_lp_pkts_acked,
 
        .owner = THIS_MODULE,

diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c
index 19ea6c2..0ac5083 100644 (file)
--- a/net/ipv4/tcp_scalable.c
+++ b/net/ipv4/tcp_scalable.c
@@ -39,7 +39,6 @@ static u32 tcp_scalable_ssthresh(struct sock *sk)
 static struct tcp_congestion_ops tcp_scalable __read_mostly = {
        .ssthresh       = tcp_scalable_ssthresh,
        .cong_avoid     = tcp_scalable_cong_avoid,
-       .min_cwnd       = tcp_reno_min_cwnd,
 
        .owner          = THIS_MODULE,
        .name           = "scalable",

diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c
index 06cae62..a022c17 100644 (file)
--- a/net/ipv4/tcp_vegas.c
+++ b/net/ipv4/tcp_vegas.c
@@ -310,7 +310,6 @@ static struct tcp_congestion_ops tcp_vegas __read_mostly = {
        .init           = tcp_vegas_init,
        .ssthresh       = tcp_reno_ssthresh,
        .cong_avoid     = tcp_vegas_cong_avoid,
-       .min_cwnd       = tcp_reno_min_cwnd,
        .pkts_acked     = tcp_vegas_pkts_acked,
        .set_state      = tcp_vegas_state,
        .cwnd_event     = tcp_vegas_cwnd_event,

diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c
index 76a1e23..b94a04a 100644 (file)
--- a/net/ipv4/tcp_westwood.c
+++ b/net/ipv4/tcp_westwood.c
@@ -276,7 +276,6 @@ static struct tcp_congestion_ops tcp_westwood __read_mostly = {
        .init           = tcp_westwood_init,
        .ssthresh       = tcp_reno_ssthresh,
        .cong_avoid     = tcp_reno_cong_avoid,
-       .min_cwnd       = tcp_westwood_bw_rttmin,
        .cwnd_event     = tcp_westwood_event,
        .get_info       = tcp_westwood_info,
        .pkts_acked     = tcp_westwood_pkts_acked,

diff --git a/net/ipv4/tcp_yeah.c b/net/ipv4/tcp_yeah.c
index 1a8d271..8eab020 100644 (file)
--- a/net/ipv4/tcp_yeah.c
+++ b/net/ipv4/tcp_yeah.c
@@ -231,7 +231,6 @@ static struct tcp_congestion_ops tcp_yeah __read_mostly = {
        .init           = tcp_yeah_init,
        .ssthresh       = tcp_yeah_ssthresh,
        .cong_avoid     = tcp_yeah_cong_avoid,
-       .min_cwnd       = tcp_reno_min_cwnd,
        .set_state      = tcp_vegas_state,
        .cwnd_event     = tcp_vegas_cwnd_event,
        .get_info       = tcp_vegas_get_info,