1// SPDX-License-Identifier: GPL-2.0 2// Test of slow start when not application-limited, so that 3// the cwnd continues to grow. 4// In this variant, the receiver sends one ACK per 4 packets. 5 6// Set up config. To keep things simple, disable the 7// mechanism that defers sending in order to send bigger TSO packets. 8`./defaults.sh 9sysctl -q net.ipv4.tcp_tso_win_divisor=100` 10 11 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 12 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 13 +0 bind(3, ..., ...) = 0 14 +0 listen(3, 1) = 0 15 16 +.1 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> 17 +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8> 18 +.1 < . 1:1(0) ack 1 win 257 19 +0 accept(3, ..., ...) = 4 20 +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0 21 22 +0 write(4, ..., 30000) = 30000 23 +0 > P. 1:10001(10000) ack 1 24 +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% 25 26 +.11 < . 1:1(0) ack 4001 win 257 27 +0 > P. 10001:18001(8000) ack 1 28 29 +.01 < . 1:1(0) ack 8001 win 257 30 +0 > P. 18001:26001(8000) ack 1 31 32+.005 < . 1:1(0) ack 10001 win 257 33 +0 > P. 26001:30001(4000) ack 1 34 35 +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }% 36