// SPDX-License-Identifier: GPL-2.0 // Test of slow start when not application-limited, so that // the cwnd continues to grow. // In this variant, the receiver sends one ACK per 4 packets. // Set up config. To keep things simple, disable the // mechanism that defers sending in order to send bigger TSO packets. `./defaults.sh sysctl -q net.ipv4.tcp_tso_win_divisor=100` 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1) = 0 +.1 < S 0:0(0) win 32792 +0 > S. 0:0(0) ack 1 +.1 < . 1:1(0) ack 1 win 257 +0 accept(3, ..., ...) = 4 +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0 +0 write(4, ..., 30000) = 30000 +0 > P. 1:10001(10000) ack 1 +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% +.11 < . 1:1(0) ack 4001 win 257 +0 > P. 10001:18001(8000) ack 1 +.01 < . 1:1(0) ack 8001 win 257 +0 > P. 18001:26001(8000) ack 1 +.005 < . 1:1(0) ack 10001 win 257 +0 > P. 26001:30001(4000) ack 1 +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }%