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1// SPDX-License-Identifier: GPL-2.02// Test of slow start when not application-limited, so that3// the cwnd continues to grow.4// In this variant, the receiver ACKs every other packet,5// approximating standard delayed ACKs.6 7// Set up config. To keep things simple, disable the8// mechanism that defers sending in order to send bigger TSO packets.9`./defaults.sh10sysctl -q net.ipv4.tcp_tso_win_divisor=100`11 12 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 313 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 014 +0 bind(3, ..., ...) = 015 +0 listen(3, 1) = 016 17 +.1 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>18 +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>19 +.1 < . 1:1(0) ack 1 win 25720 +0 accept(3, ..., ...) = 421 +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 022 23 +0 write(4, ..., 30000) = 3000024 +0 > P. 1:10001(10000) ack 125 +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }%26 27+.105 < . 1:1(0) ack 2001 win 25728 +0 > P. 10001:14001(4000) ack 129 30+.005 < . 1:1(0) ack 4001 win 25731 +0 > P. 14001:18001(4000) ack 132 33+.005 < . 1:1(0) ack 6001 win 25734 +0 > P. 18001:22001(4000) ack 135 36+.005 < . 1:1(0) ack 8001 win 25737 +0 > P. 22001:26001(4000) ack 138 39+.005 < . 1:1(0) ack 10001 win 25740 +0 > P. 26001:30001(4000) ack 141 42 +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }%43