tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
tcp: fix stretch ACK bugs in Yeah
Change Yeah to properly handle stretch ACKs in additive
increase mode by passing in the count of ACKed packets
to tcp_cong_avoid_ai().
In addition, we re-implemented the scalable path using
tcp_cong_avoid_ai() and removed the pkts_acked variable.
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
authored by
Pengcheng Yang
and committed by
David S. Miller
fa4cb9eb
ca04f5d4
+11
-30
+11
-30
net/ipv4/tcp_yeah.c
+11
-30
net/ipv4/tcp_yeah.c
···
36
36
37
37
u32 reno_count;
38
38
u32 fast_count;
39
-
40
-
u32 pkts_acked;
41
39
};
42
40
43
41
static void tcp_yeah_init(struct sock *sk)
···
55
57
tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
56
58
}
57
59
58
-
static void tcp_yeah_pkts_acked(struct sock *sk,
59
-
const struct ack_sample *sample)
60
-
{
61
-
const struct inet_connection_sock *icsk = inet_csk(sk);
62
-
struct yeah *yeah = inet_csk_ca(sk);
63
-
64
-
if (icsk->icsk_ca_state == TCP_CA_Open)
65
-
yeah->pkts_acked = sample->pkts_acked;
66
-
67
-
tcp_vegas_pkts_acked(sk, sample);
68
-
}
69
-
70
60
static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 acked)
71
61
{
72
62
struct tcp_sock *tp = tcp_sk(sk);
···
63
77
if (!tcp_is_cwnd_limited(sk))
64
78
return;
65
79
66
-
if (tcp_in_slow_start(tp))
67
-
tcp_slow_start(tp, acked);
80
+
if (tcp_in_slow_start(tp)) {
81
+
acked = tcp_slow_start(tp, acked);
82
+
if (!acked)
83
+
goto do_vegas;
84
+
}
68
85
69
-
else if (!yeah->doing_reno_now) {
86
+
if (!yeah->doing_reno_now) {
70
87
/* Scalable */
71
-
72
-
tp->snd_cwnd_cnt += yeah->pkts_acked;
73
-
if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)) {
74
-
if (tp->snd_cwnd < tp->snd_cwnd_clamp)
75
-
tp->snd_cwnd++;
76
-
tp->snd_cwnd_cnt = 0;
77
-
}
78
-
79
-
yeah->pkts_acked = 1;
80
-
88
+
tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT),
89
+
acked);
81
90
} else {
82
91
/* Reno */
83
-
tcp_cong_avoid_ai(tp, tp->snd_cwnd, 1);
92
+
tcp_cong_avoid_ai(tp, tp->snd_cwnd, acked);
84
93
}
85
94
86
95
/* The key players are v_vegas.beg_snd_una and v_beg_snd_nxt.
···
99
118
* of bytes we send in an RTT is often less than our cwnd will allow.
100
119
* So we keep track of our cwnd separately, in v_beg_snd_cwnd.
101
120
*/
102
-
121
+
do_vegas:
103
122
if (after(ack, yeah->vegas.beg_snd_nxt)) {
104
123
/* We do the Vegas calculations only if we got enough RTT
105
124
* samples that we can be reasonably sure that we got
···
213
232
.set_state = tcp_vegas_state,
214
233
.cwnd_event = tcp_vegas_cwnd_event,
215
234
.get_info = tcp_vegas_get_info,
216
-
.pkts_acked = tcp_yeah_pkts_acked,
235
+
.pkts_acked = tcp_vegas_pkts_acked,
217
236
218
237
.owner = THIS_MODULE,
219
238
.name = "yeah",