tjh.dev / kernel
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
fork atom

selftests/net: packetdrill: import tcp/slow_start

Same import process as previous tests.

Also add CONFIG_NET_SCH_FQ to config, as one test uses that.

Same test process as previous tests. Both with and without debug mode.
Recording the steps once:

make mrproper
vng --build \
--config tools/testing/selftests/net/packetdrill/config \
--config kernel/configs/debug.config
vng -v --run . --user root --cpus 4 -- \
make -C tools/testing/selftests TARGETS=net/packetdrill run_tests

Link: https://github.com/linux-netdev/nipa/wiki/How-to-run-netdev-selftests-CI-style#how-to-build
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20240912005317.1253001-4-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

authored by

Willem de Bruijn and committed by
Jakub Kicinski e874be27 1e42f73f

+427
+1
tools/testing/selftests/net/packetdrill/config
··· 3 3 CONFIG_HZ=1000 4 4 CONFIG_NET_NS=y 5 5 CONFIG_NET_SCH_FIFO=y 6 + CONFIG_NET_SCH_FQ=y 6 7 CONFIG_PROC_SYSCTL=y 7 8 CONFIG_SYN_COOKIES=y 8 9 CONFIG_TCP_CONG_CUBIC=y
+56
tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-ack-per-1pkt.pkt
··· 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 ACKs every packet. 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 9 + sysctl -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 + +.105 < . 1:1(0) ack 1001 win 257 27 + +0 > P. 10001:12001(2000) ack 1 28 + 29 + +0 < . 1:1(0) ack 2001 win 257 30 + +0 > P. 12001:14001(2000) ack 1 31 + 32 + +.005 < . 1:1(0) ack 3001 win 257 33 + +0 > P. 14001:16001(2000) ack 1 34 + 35 + +0 < . 1:1(0) ack 4001 win 257 36 + +0 > P. 16001:18001(2000) ack 1 37 + 38 + +.005 < . 1:1(0) ack 5001 win 257 39 + +0 > P. 18001:20001(2000) ack 1 40 + 41 + +0 < . 1:1(0) ack 6001 win 257 42 + +0 > P. 20001:22001(2000) ack 1 43 + 44 + +.005 < . 1:1(0) ack 7001 win 257 45 + +0 > P. 22001:24001(2000) ack 1 46 + 47 + +0 < . 1:1(0) ack 8001 win 257 48 + +0 > P. 24001:26001(2000) ack 1 49 + 50 + +.005 < . 1:1(0) ack 9001 win 257 51 + +0 > P. 26001:28001(2000) ack 1 52 + 53 + +0 < . 1:1(0) ack 10001 win 257 54 + +0 > P. 28001:30001(2000) ack 1 55 + 56 + +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }%
+33
tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-ack-per-2pkt-send-5pkt.pkt
··· 1 + // SPDX-License-Identifier: GPL-2.0 2 + // Test of slow start when an outstanding flight of packets is 3 + // less than the current cwnd, and not big enough to bump up cwnd. 4 + // 5 + // In this variant, the receiver ACKs every other packet, 6 + // approximating standard delayed ACKs. 7 + 8 + // Set up config. 9 + `./defaults.sh` 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 + +0 < 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 + +0 < . 1:1(0) ack 1 win 257 19 + +0 accept(3, ..., ...) = 4 20 + 21 + // Only send 5 packets. 22 + +0 write(4, ..., 5000) = 5000 23 + +0 > P. 1:5001(5000) ack 1 24 + +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% 25 + 26 + +0 < . 1:1(0) ack 2001 win 257 27 + +0 %{ assert tcpi_snd_cwnd == 10, 'cwnd=%d' % tcpi_snd_cwnd }% 28 + 29 + +0 < . 1:1(0) ack 4001 win 257 30 + +0 %{ assert tcpi_snd_cwnd == 10, 'cwnd=%d' % tcpi_snd_cwnd }% 31 + 32 + +0 < . 1:1(0) ack 5001 win 257 33 + +0 %{ assert tcpi_snd_cwnd == 10, 'cwnd=%d' % tcpi_snd_cwnd }%
+34
tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-ack-per-2pkt-send-6pkt.pkt
··· 1 + // SPDX-License-Identifier: GPL-2.0 2 + // Test of slow start when an outstanding flight of packets is 3 + // less than the current cwnd, but still big enough that in slow 4 + // start we want to increase our cwnd a little. 5 + // 6 + // In this variant, the receiver ACKs every other packet, 7 + // approximating standard delayed ACKs. 8 + 9 + // Set up config. 10 + `./defaults.sh` 11 + 12 + 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 13 + +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 14 + +0 bind(3, ..., ...) = 0 15 + +0 listen(3, 1) = 0 16 + 17 + +0 < 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 + +0 < . 1:1(0) ack 1 win 257 20 + +0 accept(3, ..., ...) = 4 21 + 22 + // Only send 6 packets. 23 + +0 write(4, ..., 6000) = 6000 24 + +0 > P. 1:6001(6000) ack 1 25 + +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% 26 + 27 + +0 < . 1:1(0) ack 2001 win 257 28 + +0 %{ assert tcpi_snd_cwnd == 12, 'cwnd=%d' % tcpi_snd_cwnd }% 29 + 30 + +0 < . 1:1(0) ack 4001 win 257 31 + +0 %{ assert tcpi_snd_cwnd == 12, 'cwnd=%d' % tcpi_snd_cwnd }% 32 + 33 + +0 < . 1:1(0) ack 6001 win 257 34 + +0 %{ assert tcpi_snd_cwnd == 12, 'cwnd=%d' % tcpi_snd_cwnd }%
+42
tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-ack-per-2pkt.pkt
··· 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 ACKs every other packet, 5 + // approximating standard delayed ACKs. 6 + 7 + // Set up config. To keep things simple, disable the 8 + // mechanism that defers sending in order to send bigger TSO packets. 9 + `./defaults.sh 10 + sysctl -q net.ipv4.tcp_tso_win_divisor=100` 11 + 12 + 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 13 + +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 14 + +0 bind(3, ..., ...) = 0 15 + +0 listen(3, 1) = 0 16 + 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 257 20 + +0 accept(3, ..., ...) = 4 21 + +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0 22 + 23 + +0 write(4, ..., 30000) = 30000 24 + +0 > P. 1:10001(10000) ack 1 25 + +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% 26 + 27 + +.105 < . 1:1(0) ack 2001 win 257 28 + +0 > P. 10001:14001(4000) ack 1 29 + 30 + +.005 < . 1:1(0) ack 4001 win 257 31 + +0 > P. 14001:18001(4000) ack 1 32 + 33 + +.005 < . 1:1(0) ack 6001 win 257 34 + +0 > P. 18001:22001(4000) ack 1 35 + 36 + +.005 < . 1:1(0) ack 8001 win 257 37 + +0 > P. 22001:26001(4000) ack 1 38 + 39 + +.005 < . 1:1(0) ack 10001 win 257 40 + +0 > P. 26001:30001(4000) ack 1 41 + 42 + +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }%
+35
tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-ack-per-4pkt.pkt
··· 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 9 + sysctl -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 }%
+39
tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-after-idle.pkt
··· 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_${PPID}.sh`
+50
tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-after-win-update.pkt
··· 1 + // SPDX-License-Identifier: GPL-2.0 2 + // Test of slow start after window update 3 + // This test expects tso size to be at least initial cwnd * mss 4 + 5 + `./defaults.sh 6 + ./set_sysctls.py /proc/sys/net/ipv4/tcp_slow_start_after_idle=1 \ 7 + /proc/sys/net/ipv4/tcp_min_tso_segs=10` 8 + 9 + 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 10 + +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 11 + +0 bind(3, ..., ...) = 0 12 + +0 listen(3, 1) = 0 13 + 14 + +0 < S 0:0(0) win 65535 <mss 1000,sackOK,nop,nop,nop,wscale 7> 15 + +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8> 16 + +.1 < . 1:1(0) ack 1 win 511 17 + +0 accept(3, ..., ...) = 4 18 + +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0 19 + 20 + +0 write(4, ..., 26000) = 26000 21 + +0 > P. 1:5001(5000) ack 1 22 + +0 > P. 5001:10001(5000) ack 1 23 + +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% 24 + 25 + +.1 < . 1:1(0) ack 10001 win 511 26 + +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }% 27 + +0 > P. 10001:20001(10000) ack 1 28 + +0 > P. 20001:26001(6000) ack 1 29 + 30 + +.1 < . 1:1(0) ack 26001 win 0 31 + +0 %{ assert tcpi_snd_cwnd == 36, tcpi_snd_cwnd }% 32 + 33 + +0 write(4, ..., 20000) = 20000 34 + // 1st win0 probe 35 + +.3~+.310 > . 26000:26000(0) ack 1 36 + +0 %{ assert tcpi_snd_cwnd == 36, tcpi_snd_cwnd }% 37 + 38 + // 2nd win0 probe 39 + +.6~+.620 > . 26000:26000(0) ack 1 40 + +0 %{ assert tcpi_snd_cwnd == 36, tcpi_snd_cwnd }% 41 + 42 + // 3rd win0 probe 43 + +1.2~+1.240 > . 26000:26000(0) ack 1 44 + +0 %{ assert tcpi_snd_cwnd == 36, tcpi_snd_cwnd }% 45 + 46 + +.9 < . 1:1(0) ack 26001 win 511 47 + +0 > P. 26001:31001(5000) ack 1 48 + 49 + // Reset sysctls 50 + `/tmp/sysctl_restore_${PPID}.sh`
+38
tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-app-limited-9-packets-out.pkt
··· 1 + // SPDX-License-Identifier: GPL-2.0 2 + // Test of slow start when application-limited: in this case, 3 + // with IW10, if we don't fully use our cwnd but instead 4 + // send just 9 packets, then cwnd should grow to twice that 5 + // value, or 18 packets. 6 + 7 + // Set up config. 8 + `./defaults.sh` 9 + 10 + 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 11 + +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 12 + +0 bind(3, ..., ...) = 0 13 + +0 listen(3, 1) = 0 14 + 15 + +.1 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> 16 + +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8> 17 + +.1 < . 1:1(0) ack 1 win 257 18 + +0 accept(3, ..., ...) = 4 19 + +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0 20 + 21 + +0 write(4, ..., 9000) = 9000 22 + +0 > P. 1:9001(9000) ack 1 23 + +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% 24 + 25 + +.105 < . 1:1(0) ack 2001 win 257 26 + +0 %{ assert tcpi_snd_cwnd == 12, tcpi_snd_cwnd }% 27 + 28 + +.005 < . 1:1(0) ack 4001 win 257 29 + +0 %{ assert tcpi_snd_cwnd == 14, tcpi_snd_cwnd }% 30 + 31 + +.005 < . 1:1(0) ack 6001 win 257 32 + +0 %{ assert tcpi_snd_cwnd == 16, tcpi_snd_cwnd }% 33 + 34 + +.005 < . 1:1(0) ack 8001 win 257 35 + +0 %{ assert tcpi_snd_cwnd == 18, tcpi_snd_cwnd }% 36 + 37 + +.005 < . 1:1(0) ack 9001 win 257 38 + +0 %{ assert tcpi_snd_cwnd == 18, tcpi_snd_cwnd }%
+36
tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-app-limited.pkt
··· 1 + // SPDX-License-Identifier: GPL-2.0 2 + // Test of slow start when application-limited: in this case, 3 + // with IW10, if we send exactly 10 packets then cwnd should grow to 20. 4 + 5 + // Set up config. 6 + `./defaults.sh` 7 + 8 + 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 9 + +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 10 + +0 bind(3, ..., ...) = 0 11 + +0 listen(3, 1) = 0 12 + 13 + +.1 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> 14 + +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8> 15 + +.1 < . 1:1(0) ack 1 win 257 16 + +0 accept(3, ..., ...) = 4 17 + +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0 18 + 19 + +0 write(4, ..., 10000) = 10000 20 + +0 > P. 1:10001(10000) ack 1 21 + +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% 22 + 23 + +.105 < . 1:1(0) ack 2001 win 257 24 + +0 %{ assert tcpi_snd_cwnd == 12, tcpi_snd_cwnd }% 25 + 26 + +.005 < . 1:1(0) ack 4001 win 257 27 + +0 %{ assert tcpi_snd_cwnd == 14, tcpi_snd_cwnd }% 28 + 29 + +.005 < . 1:1(0) ack 6001 win 257 30 + +0 %{ assert tcpi_snd_cwnd == 16, tcpi_snd_cwnd }% 31 + 32 + +.005 < . 1:1(0) ack 8001 win 257 33 + +0 %{ assert tcpi_snd_cwnd == 18, tcpi_snd_cwnd }% 34 + 35 + +.005 < . 1:1(0) ack 10001 win 257 36 + +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }%
+63
tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-fq-ack-per-2pkt.pkt
··· 1 + // SPDX-License-Identifier: GPL-2.0 2 + // Test of slow start when not application-limited, so that 3 + // the cwnd continues to grow, even if TSQ triggers. 4 + // In this variant, the receiver ACKs every other packet, 5 + // approximating standard delayed ACKs. 6 + 7 + // Note we use FQ/pacing to check if TCP Small Queues is not hurting 8 + 9 + `./defaults.sh 10 + tc qdisc replace dev tun0 root fq 11 + sysctl -q net/ipv4/tcp_pacing_ss_ratio=200 12 + sysctl -e -q net.ipv4.tcp_min_tso_segs=2` 13 + 14 + 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 15 + +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 16 + +0 bind(3, ..., ...) = 0 17 + +0 listen(3, 1) = 0 18 + 19 + +.1 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7> 20 + +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8> 21 + +.1 < . 1:1(0) ack 1 win 500 22 + +0 accept(3, ..., ...) = 4 23 + +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0 24 + 25 + +0 write(4, ..., 40000) = 40000 26 + // This might change if we cook the initial packet with 10 MSS. 27 + +0 > P. 1:2921(2920) ack 1 28 + +0 > P. 2921:5841(2920) ack 1 29 + +0 > P. 5841:8761(2920) ack 1 30 + +0 > P. 8761:11681(2920) ack 1 31 + +0 > P. 11681:14601(2920) ack 1 32 + +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% 33 + 34 + +.105 < . 1:1(0) ack 2921 win 500 35 + +0 %{ assert tcpi_snd_cwnd == 12, tcpi_snd_cwnd }% 36 + 37 + // Note: after this commit : "net_sched: sch_fq: account for schedule/timers drifts" 38 + // FQ notices that this packet missed the 'time to send next packet' computed 39 + // when prior packet (11681:14601(2920)) was sent. 40 + // So FQ will allow following packet to be sent a bit earlier (quantum/2) 41 + // (FQ commit allows an application/cwnd limited flow to get at most quantum/2 extra credit) 42 + +0 > P. 14601:17521(2920) ack 1 43 + 44 + +.003 < . 1:1(0) ack 5841 win 500 45 + +0 %{ assert tcpi_snd_cwnd == 14, tcpi_snd_cwnd }% 46 + 47 + +.001 > P. 17521:20441(2920) ack 1 48 + 49 + +.001 < . 1:1(0) ack 8761 win 500 50 + +0 %{ assert tcpi_snd_cwnd == 16, tcpi_snd_cwnd }% 51 + 52 + // remaining packets are delivered at a constant rate. 53 + +.007 > P. 20441:23361(2920) ack 1 54 + 55 + +.002 < . 1:1(0) ack 11681 win 500 56 + +0 %{ assert tcpi_snd_cwnd == 18, tcpi_snd_cwnd }% 57 + +.001 < . 1:1(0) ack 14601 win 500 58 + 59 + +.004 > P. 23361:26281(2920) ack 1 60 + 61 + +.007 > P. 26281:29201(2920) ack 1 62 + 63 + +0 %{ assert tcpi_snd_cwnd == 20, 'cwnd=%d' % tcpi_snd_cwnd }%