1// SPDX-License-Identifier: GPL-2.0 2// Test of slow start after idle 3// This test expects tso size to be at least initial cwnd * mss 4 5`./defaults.sh 6./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) = 3 10 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 11 +0 bind(3, ..., ...) = 0 12 +0 listen(3, 1) = 0 13 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 511 17 +0 accept(3, ..., ...) = 4 18 +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0 19 20 +0 write(4, ..., 26000) = 26000 21 +0 > P. 1:5001(5000) ack 1 22 +0 > P. 5001:10001(5000) ack 1 23 +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% 24 25 +.1 < . 1:1(0) ack 10001 win 511 26 +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }% 27 +0 > P. 10001:20001(10000) ack 1 28 +0 > P. 20001:26001(6000) ack 1 29 30 +.1 < . 1:1(0) ack 26001 win 511 31 +0 %{ assert tcpi_snd_cwnd == 36, tcpi_snd_cwnd }% 32 33 +2 write(4, ..., 20000) = 20000 34// If slow start after idle works properly, we should send 5 MSS here (cwnd/2) 35 +0 > P. 26001:31001(5000) ack 1 36 +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% 37 38// Reset sysctls 39`/tmp/sysctl_restore_${PPID}.sh` 40