Commit 66ac08a7 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'tcp_delack_max' 



Eric Dumazet says:

====================
tcp: add tcp_delack_max()

First patches are adding const qualifiers to four existing helpers.

Third patch adds a much needed companion feature to RTAX_RTO_MIN.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 236f3873 bbf80d71

include/net/sock.h

+2 −2
Original line number Diff line number Diff line
@@ -2141,14 +2141,14 @@ static inline bool sk_rethink_txhash(struct sock *sk) 
}



static inline struct dst_entry *

__sk_dst_get(struct sock *sk)

__sk_dst_get(const struct sock *sk)

{

	return rcu_dereference_check(sk->sk_dst_cache,

				     lockdep_sock_is_held(sk));

}



static inline struct dst_entry *

sk_dst_get(struct sock *sk)

sk_dst_get(const struct sock *sk)

{

	struct dst_entry *dst;

include/net/tcp.h

+4 −2
Original line number Diff line number Diff line
@@ -718,8 +718,10 @@ static inline void tcp_fast_path_check(struct sock *sk) 
		tcp_fast_path_on(tp);

}



u32 tcp_delack_max(const struct sock *sk);



/* Compute the actual rto_min value */

static inline u32 tcp_rto_min(struct sock *sk)

static inline u32 tcp_rto_min(const struct sock *sk)

{

	const struct dst_entry *dst = __sk_dst_get(sk);

	u32 rto_min = inet_csk(sk)->icsk_rto_min;
@@ -729,7 +731,7 @@ static inline u32 tcp_rto_min(struct sock *sk) 
	return rto_min;

}



static inline u32 tcp_rto_min_us(struct sock *sk)

static inline u32 tcp_rto_min_us(const struct sock *sk)

{

	return jiffies_to_usecs(tcp_rto_min(sk));

}

net/ipv4/tcp.c

+2 −1
Original line number Diff line number Diff line
@@ -3762,7 +3762,8 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) 
		info->tcpi_options |= TCPI_OPT_SYN_DATA;



	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);

	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);

	info->tcpi_ato = jiffies_to_usecs(min(icsk->icsk_ack.ato,

					      tcp_delack_max(sk)));

	info->tcpi_snd_mss = tp->mss_cache;

	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;

net/ipv4/tcp_output.c

+15 −1
Original line number Diff line number Diff line
@@ -3977,6 +3977,20 @@ int tcp_connect(struct sock *sk) 
}

EXPORT_SYMBOL(tcp_connect);



u32 tcp_delack_max(const struct sock *sk)

{

	const struct dst_entry *dst = __sk_dst_get(sk);

	u32 delack_max = inet_csk(sk)->icsk_delack_max;



	if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) {

		u32 rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN);

		u32 delack_from_rto_min = max_t(int, 1, rto_min - 1);



		delack_max = min_t(u32, delack_max, delack_from_rto_min);

	}

	return delack_max;

}



/* Send out a delayed ack, the caller does the policy checking

 * to see if we should even be here.  See tcp_input.c:tcp_ack_snd_check()

 * for details.
@@ -4012,7 +4026,7 @@ void tcp_send_delayed_ack(struct sock *sk) 
		ato = min(ato, max_ato);

	}



	ato = min_t(u32, ato, inet_csk(sk)->icsk_delack_max);

	ato = min_t(u32, ato, tcp_delack_max(sk));



	/* Stay within the limit we were given */

	timeout = jiffies + ato;