diff options
| author |   Pengcheng Yang <yangpc@wangsu.com> | 2020-03-16 14:35:08 +0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2020-03-16 18:26:54 -0700 |
| commit | 5415e3c37a657f7b400ece28e73a6f6c6cc371c4 (patch) | |
| tree | f1ba3fe5fede1b2ead7306607cc7240d60ab6be7 /net/ipv4 | |
| parent | tcp: fix stretch ACK bugs in BIC (diff) | |
| download | linux-dev-5415e3c37a657f7b400ece28e73a6f6c6cc371c4.tar.xz linux-dev-5415e3c37a657f7b400ece28e73a6f6c6cc371c4.zip | |
tcp: fix stretch ACK bugs in Scalable
Change Scalable to properly handle stretch ACKs in additive
increase mode by passing in the count of ACKed packets to
tcp_cong_avoid_ai().
In addition, because we are now precisely accounting for
stretch ACKs, including delayed ACKs, we can now change
TCP_SCALABLE_AI_CNT to 100.
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_scalable.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c index 471571e1ab26..6cebf412d590 100644 --- a/net/ipv4/tcp_scalable.c +++ b/net/ipv4/tcp_scalable.c @@ -10,10 +10,9 @@ #include <net/tcp.h> /* These factors derived from the recommended values in the aer: - * .01 and and 7/8. We use 50 instead of 100 to account for - * delayed ack. + * .01 and and 7/8. */ -#define TCP_SCALABLE_AI_CNT 50U +#define TCP_SCALABLE_AI_CNT 100U #define TCP_SCALABLE_MD_SCALE 3 static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 acked) @@ -23,11 +22,13 @@ static void tcp_scalable_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); - else - tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT), - 1); + if (tcp_in_slow_start(tp)) { + acked = tcp_slow_start(tp, acked); + if (!acked) + return; + } + tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT), + acked); } static u32 tcp_scalable_ssthresh(struct sock *sk) |