From: Pengcheng Yang <yangpc@wangsu.com>
To: edumazet@google.com, ncardwell@google.com, davem@davemloft.net
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Pengcheng Yang <yangpc@wangsu.com>
Subject: [PATCH RESEND net-next v2 5/5] tcp: fix stretch ACK bugs in Yeah
Date: Mon, 16 Mar 2020 14:35:11 +0800 [thread overview]
Message-ID: <1584340511-9870-6-git-send-email-yangpc@wangsu.com> (raw)
In-Reply-To: <1584340511-9870-1-git-send-email-yangpc@wangsu.com>
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>
---
net/ipv4/tcp_yeah.c | 41 +++++++++++------------------------------
1 file changed, 11 insertions(+), 30 deletions(-)
diff --git a/net/ipv4/tcp_yeah.c b/net/ipv4/tcp_yeah.c
index e00570d..3bb4487 100644
--- a/net/ipv4/tcp_yeah.c
+++ b/net/ipv4/tcp_yeah.c
@@ -36,8 +36,6 @@ struct yeah {
u32 reno_count;
u32 fast_count;
-
- u32 pkts_acked;
};
static void tcp_yeah_init(struct sock *sk)
@@ -57,18 +55,6 @@ static void tcp_yeah_init(struct sock *sk)
tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
}
-static void tcp_yeah_pkts_acked(struct sock *sk,
- const struct ack_sample *sample)
-{
- const struct inet_connection_sock *icsk = inet_csk(sk);
- struct yeah *yeah = inet_csk_ca(sk);
-
- if (icsk->icsk_ca_state == TCP_CA_Open)
- yeah->pkts_acked = sample->pkts_acked;
-
- tcp_vegas_pkts_acked(sk, sample);
-}
-
static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 acked)
{
struct tcp_sock *tp = tcp_sk(sk);
@@ -77,24 +63,19 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 acked)
if (!tcp_is_cwnd_limited(sk))
return;
- if (tcp_in_slow_start(tp))
- tcp_slow_start(tp, acked);
+ if (tcp_in_slow_start(tp)) {
+ acked = tcp_slow_start(tp, acked);
+ if (!acked)
+ goto do_vegas;
+ }
- else if (!yeah->doing_reno_now) {
+ if (!yeah->doing_reno_now) {
/* Scalable */
-
- tp->snd_cwnd_cnt += yeah->pkts_acked;
- if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)) {
- if (tp->snd_cwnd < tp->snd_cwnd_clamp)
- tp->snd_cwnd++;
- tp->snd_cwnd_cnt = 0;
- }
-
- yeah->pkts_acked = 1;
-
+ tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT),
+ acked);
} else {
/* Reno */
- tcp_cong_avoid_ai(tp, tp->snd_cwnd, 1);
+ tcp_cong_avoid_ai(tp, tp->snd_cwnd, acked);
}
/* The key players are v_vegas.beg_snd_una and v_beg_snd_nxt.
@@ -118,7 +99,7 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 acked)
* of bytes we send in an RTT is often less than our cwnd will allow.
* So we keep track of our cwnd separately, in v_beg_snd_cwnd.
*/
-
+do_vegas:
if (after(ack, yeah->vegas.beg_snd_nxt)) {
/* We do the Vegas calculations only if we got enough RTT
* samples that we can be reasonably sure that we got
@@ -232,7 +213,7 @@ static u32 tcp_yeah_ssthresh(struct sock *sk)
.set_state = tcp_vegas_state,
.cwnd_event = tcp_vegas_cwnd_event,
.get_info = tcp_vegas_get_info,
- .pkts_acked = tcp_yeah_pkts_acked,
+ .pkts_acked = tcp_vegas_pkts_acked,
.owner = THIS_MODULE,
.name = "yeah",
--
1.8.3.1
next prev parent reply other threads:[~2020-03-16 6:49 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-16 6:35 [PATCH RESEND net-next v2 0/5] tcp: fix stretch ACK bugs in congestion control modules Pengcheng Yang
2020-03-16 6:35 ` [PATCH RESEND net-next v2 1/5] tcp: fix stretch ACK bugs in BIC Pengcheng Yang
2020-03-16 21:19 ` Neal Cardwell
2020-03-16 6:35 ` [PATCH RESEND net-next v2 2/5] tcp: fix stretch ACK bugs in Scalable Pengcheng Yang
2020-03-16 21:25 ` Neal Cardwell
2020-03-16 6:35 ` [PATCH RESEND net-next v2 3/5] tcp: stretch ACK fixes in Veno prep Pengcheng Yang
2020-03-16 21:42 ` Neal Cardwell
2020-03-16 6:35 ` [PATCH RESEND net-next v2 4/5] tcp: fix stretch ACK bugs in Veno Pengcheng Yang
2020-03-16 21:46 ` Neal Cardwell
2020-03-16 6:35 ` Pengcheng Yang [this message]
2020-03-17 1:27 ` [PATCH RESEND net-next v2 0/5] tcp: fix stretch ACK bugs in congestion control modules David Miller
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