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1// SPDX-License-Identifier: GPL-2.02// Test of slow start after idle3// This test expects tso size to be at least initial cwnd * mss4 5`./defaults.sh6./set_sysctls.py /proc/sys/net/ipv4/tcp_slow_start_after_idle=1 \7 /proc/sys/net/ipv4/tcp_min_tso_segs=10`8 9 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 310 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 011 +0 bind(3, ..., ...) = 012 +0 listen(3, 1) = 013 14 +0 < S 0:0(0) win 65535 <mss 1000,sackOK,nop,nop,nop,wscale 7>15 +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>16 +.1 < . 1:1(0) ack 1 win 51117 +0 accept(3, ..., ...) = 418 +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 019 20 +0 write(4, ..., 26000) = 2600021 +0 > P. 1:5001(5000) ack 122 +0 > P. 5001:10001(5000) ack 123 +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }%24 25 +.1 < . 1:1(0) ack 10001 win 51126 +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }%27 +0 > P. 10001:20001(10000) ack 128 +0 > P. 20001:26001(6000) ack 129 30 +.1 < . 1:1(0) ack 26001 win 51131 +0 %{ assert tcpi_snd_cwnd == 36, tcpi_snd_cwnd }%32 33 +2 write(4, ..., 20000) = 2000034// If slow start after idle works properly, we should send 5 MSS here (cwnd/2)35 +0 > P. 26001:31001(5000) ack 136 +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }%37 38// Reset sysctls39`/tmp/sysctl_restore_${PPID}.sh`40