tcp: retire FACK loss detection
FACK loss detection has been disabled by default and the
successor RACK subsumed FACK and can handle reordering better.
This patch removes FACK to simplify TCP loss recovery.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Priyaranjan Jha <priyarjha@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 2f2c69a..ed71511 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -384,7 +384,6 @@ void tcp_update_metrics(struct sock *sk);
void tcp_init_metrics(struct sock *sk);
void tcp_metrics_init(void);
bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst);
-void tcp_disable_fack(struct tcp_sock *tp);
void tcp_close(struct sock *sk, long timeout);
void tcp_init_sock(struct sock *sk);
void tcp_init_transfer(struct sock *sk, int bpf_op);
@@ -776,7 +775,7 @@ struct tcp_skb_cb {
};
__u8 tcp_flags; /* TCP header flags. (tcp[13]) */
- __u8 sacked; /* State flags for SACK/FACK. */
+ __u8 sacked; /* State flags for SACK. */
#define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
#define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
#define TCPCB_LOST 0x04 /* SKB is lost */
@@ -1066,7 +1065,6 @@ void tcp_rate_check_app_limited(struct sock *sk);
*
* tcp_is_sack - SACK enabled
* tcp_is_reno - No SACK
- * tcp_is_fack - FACK enabled, implies SACK enabled
*/
static inline int tcp_is_sack(const struct tcp_sock *tp)
{
@@ -1078,16 +1076,6 @@ static inline bool tcp_is_reno(const struct tcp_sock *tp)
return !tcp_is_sack(tp);
}
-static inline bool tcp_is_fack(const struct tcp_sock *tp)
-{
- return tp->rx_opt.sack_ok & TCP_FACK_ENABLED;
-}
-
-static inline void tcp_enable_fack(struct tcp_sock *tp)
-{
- tp->rx_opt.sack_ok |= TCP_FACK_ENABLED;
-}
-
static inline unsigned int tcp_left_out(const struct tcp_sock *tp)
{
return tp->sacked_out + tp->lost_out;