tcp: Refactor pingpong code

Instead of using pingpong as a single bit information, we refactor the
code to treat it as a counter. When interactive session is detected,
we set pingpong count to TCP_PINGPONG_THRESH. And when pingpong count
is >= TCP_PINGPONG_THRESH, we consider the session in pingpong mode.

This patch is a pure refactor and sets foundation for the next patch.
This patch itself does not change any pingpong logic.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wei Wang 2019-01-25 10:53:19 -08:00 committed by David S. Miller
parent fb1b699991
commit 31954cd8bb
9 changed files with 35 additions and 18 deletions

View File

@ -314,4 +314,21 @@ int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, unsigned int optlen);
struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
#define TCP_PINGPONG_THRESH 1
static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
{
inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
}
static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
{
inet_csk(sk)->icsk_ack.pingpong = 0;
}
static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
{
return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
}
#endif /* _INET_CONNECTION_SOCK_H */

View File

@ -480,7 +480,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
}
if (sk->sk_write_pending || icsk->icsk_ack.pingpong ||
if (sk->sk_write_pending || inet_csk_in_pingpong_mode(sk) ||
icsk->icsk_accept_queue.rskq_defer_accept) {
/* Save one ACK. Data will be ready after
* several ticks, if write_pending is set.

View File

@ -199,7 +199,7 @@ static void dccp_delack_timer(struct timer_list *t)
icsk->icsk_ack.pending &= ~ICSK_ACK_TIMER;
if (inet_csk_ack_scheduled(sk)) {
if (!icsk->icsk_ack.pingpong) {
if (!inet_csk_in_pingpong_mode(sk)) {
/* Delayed ACK missed: inflate ATO. */
icsk->icsk_ack.ato = min(icsk->icsk_ack.ato << 1,
icsk->icsk_rto);
@ -207,7 +207,7 @@ static void dccp_delack_timer(struct timer_list *t)
/* Delayed ACK missed: leave pingpong mode and
* deflate ATO.
*/
icsk->icsk_ack.pingpong = 0;
inet_csk_exit_pingpong_mode(sk);
icsk->icsk_ack.ato = TCP_ATO_MIN;
}
dccp_send_ack(sk);

View File

@ -1551,7 +1551,7 @@ static void tcp_cleanup_rbuf(struct sock *sk, int copied)
(copied > 0 &&
((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
!icsk->icsk_ack.pingpong)) &&
!inet_csk_in_pingpong_mode(sk))) &&
!atomic_read(&sk->sk_rmem_alloc)))
time_to_ack = true;
}
@ -2984,16 +2984,16 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
case TCP_QUICKACK:
if (!val) {
icsk->icsk_ack.pingpong = 1;
inet_csk_enter_pingpong_mode(sk);
} else {
icsk->icsk_ack.pingpong = 0;
inet_csk_exit_pingpong_mode(sk);
if ((1 << sk->sk_state) &
(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
inet_csk_ack_scheduled(sk)) {
icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
tcp_cleanup_rbuf(sk, 1);
if (!(val & 1))
icsk->icsk_ack.pingpong = 1;
inet_csk_enter_pingpong_mode(sk);
}
}
break;
@ -3407,7 +3407,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
return 0;
}
case TCP_QUICKACK:
val = !icsk->icsk_ack.pingpong;
val = !inet_csk_in_pingpong_mode(sk);
break;
case TCP_CONGESTION:

View File

@ -221,7 +221,7 @@ void tcp_enter_quickack_mode(struct sock *sk, unsigned int max_quickacks)
struct inet_connection_sock *icsk = inet_csk(sk);
tcp_incr_quickack(sk, max_quickacks);
icsk->icsk_ack.pingpong = 0;
inet_csk_exit_pingpong_mode(sk);
icsk->icsk_ack.ato = TCP_ATO_MIN;
}
EXPORT_SYMBOL(tcp_enter_quickack_mode);
@ -236,7 +236,7 @@ static bool tcp_in_quickack_mode(struct sock *sk)
const struct dst_entry *dst = __sk_dst_get(sk);
return (dst && dst_metric(dst, RTAX_QUICKACK)) ||
(icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);
(icsk->icsk_ack.quick && !inet_csk_in_pingpong_mode(sk));
}
static void tcp_ecn_queue_cwr(struct tcp_sock *tp)
@ -4094,7 +4094,7 @@ void tcp_fin(struct sock *sk)
case TCP_ESTABLISHED:
/* Move to CLOSE_WAIT */
tcp_set_state(sk, TCP_CLOSE_WAIT);
inet_csk(sk)->icsk_ack.pingpong = 1;
inet_csk_enter_pingpong_mode(sk);
break;
case TCP_CLOSE_WAIT:
@ -5889,7 +5889,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
return -1;
if (sk->sk_write_pending ||
icsk->icsk_accept_queue.rskq_defer_accept ||
icsk->icsk_ack.pingpong) {
inet_csk_in_pingpong_mode(sk)) {
/* Save one ACK. Data will be ready after
* several ticks, if write_pending is set.
*

View File

@ -2437,7 +2437,7 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
refcount_read(&sk->sk_refcnt), sk,
jiffies_to_clock_t(icsk->icsk_rto),
jiffies_to_clock_t(icsk->icsk_ack.ato),
(icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
(icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sk),
tp->snd_cwnd,
state == TCP_LISTEN ?
fastopenq->max_qlen :

View File

@ -171,7 +171,7 @@ static void tcp_event_data_sent(struct tcp_sock *tp,
* packet, enter pingpong mode.
*/
if ((u32)(now - icsk->icsk_ack.lrcvtime) < icsk->icsk_ack.ato)
icsk->icsk_ack.pingpong = 1;
inet_csk_enter_pingpong_mode(sk);
}
/* Account for an ACK we sent. */
@ -3569,7 +3569,7 @@ void tcp_send_delayed_ack(struct sock *sk)
const struct tcp_sock *tp = tcp_sk(sk);
int max_ato = HZ / 2;
if (icsk->icsk_ack.pingpong ||
if (inet_csk_in_pingpong_mode(sk) ||
(icsk->icsk_ack.pending & ICSK_ACK_PUSHED))
max_ato = TCP_DELACK_MAX;

View File

@ -277,14 +277,14 @@ void tcp_delack_timer_handler(struct sock *sk)
icsk->icsk_ack.pending &= ~ICSK_ACK_TIMER;
if (inet_csk_ack_scheduled(sk)) {
if (!icsk->icsk_ack.pingpong) {
if (!inet_csk_in_pingpong_mode(sk)) {
/* Delayed ACK missed: inflate ATO. */
icsk->icsk_ack.ato = min(icsk->icsk_ack.ato << 1, icsk->icsk_rto);
} else {
/* Delayed ACK missed: leave pingpong mode and
* deflate ATO.
*/
icsk->icsk_ack.pingpong = 0;
inet_csk_exit_pingpong_mode(sk);
icsk->icsk_ack.ato = TCP_ATO_MIN;
}
tcp_mstamp_refresh(tcp_sk(sk));

View File

@ -1864,7 +1864,7 @@ static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
refcount_read(&sp->sk_refcnt), sp,
jiffies_to_clock_t(icsk->icsk_rto),
jiffies_to_clock_t(icsk->icsk_ack.ato),
(icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
(icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
tp->snd_cwnd,
state == TCP_LISTEN ?
fastopenq->max_qlen :