From patchwork Sun Feb 2 03:38:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 11361523 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 05BD4924 for ; Sun, 2 Feb 2020 03:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4F052082E for ; Sun, 2 Feb 2020 03:39:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MV4IgFAc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726992AbgBBDi6 (ORCPT ); Sat, 1 Feb 2020 22:38:58 -0500 Received: from mail-pf1-f194.google.com ([209.85.210.194]:42011 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726789AbgBBDi5 (ORCPT ); Sat, 1 Feb 2020 22:38:57 -0500 Received: by mail-pf1-f194.google.com with SMTP id 4so5629504pfz.9; Sat, 01 Feb 2020 19:38:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=d32kO5MNmp/RklBoxabba45xsh+0d41hE5SnVb1Zw90=; b=MV4IgFAcmz4XdEmDE1V6xh9oVQJAK2spyiKNboRNVS0OZEAs6eeV1MRvs1C8RJKpLE qPZFIzHlDlS/yBsIWxAH/zG2Khi7Iy9w/niOgdnrx4DhxaRqqX9SF2oavWRB3/Ws6Hzf 8JizLS+Sp5GrJHB7Ub8Yu2IDPW0Z3+IlT8IZgh0f/vbcQG3QX+jlLDRST2KsNYs/wJWR KAHG8qGXZcmI2E8+nm6McwuV+f2946X1nzH2KjiAMV+v/3Dy33/5k52NA1Rnnj23SrEX W+/fhXpC2GT1q24+eNIJkSBgK7fyWW3VoWiqTZFNQLjQOty4AdXPf++NFZA6alJGKSOL 5fXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=d32kO5MNmp/RklBoxabba45xsh+0d41hE5SnVb1Zw90=; b=T42IUaU3L523mZN+T+tK7iZTql3Gnk/8Tam9r4HXfYDAKbxdmaKe3ZLEfu6CVRUeB2 2b9VIguHT5TeSXqR3HV6ExaV7XW6Np9NI+M0Am6fX7UGGwl/1vjd0SKpci0Pv48wbfJc sO3UV67T61nPKPDbTvBmSoBMHJYguvPZ7MDfNXBvR5JoCYh8Ub2WOVo0wwud64JF68Av LQBn2O8pQE9TDaKvpebutYl7wyJtGeatKrHIGh28vPdxWJ4JedqYH8Wj6NXV2LExtjQQ 5MdIOnJ+a7lxvoOtNCG2Nnc6FSYZTJ1GIyT6lKzA9Hid9pwQgTMAw/j4HLFS3aciPXkY Pxaw== X-Gm-Message-State: APjAAAWYStObMMqmcHLEMNHACy92a669TfbDLS92lOk1DLqPOyJCO8m2 f06Jr4cEIAhlgfVCps3+p+U= X-Google-Smtp-Source: APXvYqw6gPQOqL/y0ye+tSAeIj6hgql//SeDyIxWHOQ904mqBVT8wII8dI8JXD539amJd2msyKj+rg== X-Received: by 2002:a63:5f4e:: with SMTP id t75mr53722pgb.7.1580614736240; Sat, 01 Feb 2020 19:38:56 -0800 (PST) Received: from localhost.localdomain ([116.84.110.10]) by smtp.gmail.com with ESMTPSA id iq22sm15705334pjb.9.2020.02.01.19.38.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 01 Feb 2020 19:38:55 -0800 (PST) From: sj38.park@gmail.com To: edumazet@google.com Cc: sj38.park@gmail.com, David.Laight@aculab.com, aams@amazon.com, davem@davemloft.net, eric.dumazet@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, ncardwell@google.com, shuah@kernel.org, sjpark@amazon.de Subject: [PATCH v3 2/2] selftests: net: Add FIN_ACK processing order related latency spike test Date: Sun, 2 Feb 2020 03:38:27 +0000 Message-Id: <20200202033827.16304-3-sj38.park@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200202033827.16304-1-sj38.park@gmail.com> References: <20200202033827.16304-1-sj38.park@gmail.com> Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: SeongJae Park This commit adds a test for FIN_ACK process races related reconnection latency spike issues. The issue has described and solved by the previous commit ("tcp: Reduce SYN resend delay if a suspicous ACK is received"). The test program is configured with a server and a client process. The server creates and binds a socket to a port that dynamically allocated, listen on it, and start a infinite loop. Inside the loop, it accepts connection, reads 4 bytes from the socket, and closes the connection. The client is constructed as an infinite loop. Inside the loop, it creates a socket with LINGER and NODELAY option, connect to the server, send 4 bytes data, try read some data from server. After the read() returns, it measure the latency from the beginning of this loop to this point and if the latency is larger than 1 second (spike), print a message. Reviewed-by: Eric Dumazet Signed-off-by: SeongJae Park --- tools/testing/selftests/net/.gitignore | 1 + tools/testing/selftests/net/Makefile | 2 + tools/testing/selftests/net/fin_ack_lat.c | 151 +++++++++++++++++++++ tools/testing/selftests/net/fin_ack_lat.sh | 35 +++++ 4 files changed, 189 insertions(+) create mode 100644 tools/testing/selftests/net/fin_ack_lat.c create mode 100755 tools/testing/selftests/net/fin_ack_lat.sh diff --git a/tools/testing/selftests/net/.gitignore b/tools/testing/selftests/net/.gitignore index 8aefd81fbc86..ecc52d4c034d 100644 --- a/tools/testing/selftests/net/.gitignore +++ b/tools/testing/selftests/net/.gitignore @@ -22,3 +22,4 @@ ipv6_flowlabel_mgr so_txtime tcp_fastopen_backup_key nettest +fin_ack_lat diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index a8e04d665b69..b5694196430a 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -11,6 +11,7 @@ TEST_PROGS += udpgso_bench.sh fib_rule_tests.sh msg_zerocopy.sh psock_snd.sh TEST_PROGS += udpgro_bench.sh udpgro.sh test_vxlan_under_vrf.sh reuseport_addr_any.sh TEST_PROGS += test_vxlan_fdb_changelink.sh so_txtime.sh ipv6_flowlabel.sh TEST_PROGS += tcp_fastopen_backup_key.sh fcnal-test.sh l2tp.sh traceroute.sh +TEST_PROGS += fin_ack_lat.sh TEST_PROGS_EXTENDED := in_netns.sh TEST_GEN_FILES = socket nettest TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy reuseport_addr_any @@ -18,6 +19,7 @@ TEST_GEN_FILES += tcp_mmap tcp_inq psock_snd txring_overwrite TEST_GEN_FILES += udpgso udpgso_bench_tx udpgso_bench_rx ip_defrag TEST_GEN_FILES += so_txtime ipv6_flowlabel ipv6_flowlabel_mgr TEST_GEN_FILES += tcp_fastopen_backup_key +TEST_GEN_FILES += fin_ack_lat TEST_GEN_PROGS = reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls diff --git a/tools/testing/selftests/net/fin_ack_lat.c b/tools/testing/selftests/net/fin_ack_lat.c new file mode 100644 index 000000000000..70187494b57a --- /dev/null +++ b/tools/testing/selftests/net/fin_ack_lat.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static int child_pid; + +static unsigned long timediff(struct timeval s, struct timeval e) +{ + unsigned long s_us, e_us; + + s_us = s.tv_sec * 1000000 + s.tv_usec; + e_us = e.tv_sec * 1000000 + e.tv_usec; + if (s_us > e_us) + return 0; + return e_us - s_us; +} + +static void client(int port) +{ + int sock = 0; + struct sockaddr_in addr, laddr; + socklen_t len = sizeof(laddr); + struct linger sl; + int flag = 1; + int buffer; + struct timeval start, end; + unsigned long lat, sum_lat = 0, nr_lat = 0; + + while (1) { + gettimeofday(&start, NULL); + + sock = socket(AF_INET, SOCK_STREAM, 0); + if (sock < 0) + error(-1, errno, "socket creation"); + + sl.l_onoff = 1; + sl.l_linger = 0; + if (setsockopt(sock, SOL_SOCKET, SO_LINGER, &sl, sizeof(sl))) + error(-1, errno, "setsockopt(linger)"); + + if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, + &flag, sizeof(flag))) + error(-1, errno, "setsockopt(nodelay)"); + + addr.sin_family = AF_INET; + addr.sin_port = htons(port); + + if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) <= 0) + error(-1, errno, "inet_pton"); + + if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) + error(-1, errno, "connect"); + + send(sock, &buffer, sizeof(buffer), 0); + if (read(sock, &buffer, sizeof(buffer)) == -1) + error(-1, errno, "waiting read"); + + gettimeofday(&end, NULL); + lat = timediff(start, end); + sum_lat += lat; + nr_lat++; + if (lat < 100000) + goto close; + + if (getsockname(sock, (struct sockaddr *)&laddr, &len) == -1) + error(-1, errno, "getsockname"); + printf("port: %d, lat: %lu, avg: %lu, nr: %lu\n", + ntohs(laddr.sin_port), lat, + sum_lat / nr_lat, nr_lat); +close: + fflush(stdout); + close(sock); + } +} + +static void server(int sock, struct sockaddr_in address) +{ + int accepted; + int addrlen = sizeof(address); + int buffer; + + while (1) { + accepted = accept(sock, (struct sockaddr *)&address, + (socklen_t *)&addrlen); + if (accepted < 0) + error(-1, errno, "accept"); + + if (read(accepted, &buffer, sizeof(buffer)) == -1) + error(-1, errno, "read"); + close(accepted); + } +} + +static void sig_handler(int signum) +{ + kill(SIGTERM, child_pid); + exit(0); +} + +int main(int argc, char const *argv[]) +{ + int sock; + int opt = 1; + struct sockaddr_in address; + struct sockaddr_in laddr; + socklen_t len = sizeof(laddr); + + if (signal(SIGTERM, sig_handler) == SIG_ERR) + error(-1, errno, "signal"); + + sock = socket(AF_INET, SOCK_STREAM, 0); + if (sock < 0) + error(-1, errno, "socket"); + + if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, + &opt, sizeof(opt)) == -1) + error(-1, errno, "setsockopt"); + + address.sin_family = AF_INET; + address.sin_addr.s_addr = INADDR_ANY; + /* dynamically allocate unused port */ + address.sin_port = 0; + + if (bind(sock, (struct sockaddr *)&address, sizeof(address)) < 0) + error(-1, errno, "bind"); + + if (listen(sock, 3) < 0) + error(-1, errno, "listen"); + + if (getsockname(sock, (struct sockaddr *)&laddr, &len) == -1) + error(-1, errno, "getsockname"); + + fprintf(stderr, "server port: %d\n", ntohs(laddr.sin_port)); + child_pid = fork(); + if (!child_pid) + client(ntohs(laddr.sin_port)); + else + server(sock, laddr); + + return 0; +} diff --git a/tools/testing/selftests/net/fin_ack_lat.sh b/tools/testing/selftests/net/fin_ack_lat.sh new file mode 100755 index 000000000000..a3ff6e0b2c7a --- /dev/null +++ b/tools/testing/selftests/net/fin_ack_lat.sh @@ -0,0 +1,35 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Test latency spikes caused by FIN/ACK handling race. + +set +x +set -e + +tmpfile=$(mktemp /tmp/fin_ack_latency.XXXX.log) + +cleanup() { + kill $(pidof fin_ack_lat) + rm -f $tmpfile +} + +trap cleanup EXIT + +do_test() { + RUNTIME=$1 + + ./fin_ack_lat | tee $tmpfile & + PID=$! + + sleep $RUNTIME + NR_SPIKES=$(wc -l $tmpfile | awk '{print $1}') + if [ $NR_SPIKES -gt 0 ] + then + echo "FAIL: $NR_SPIKES spikes detected" + return 1 + fi + return 0 +} + +do_test "30" +echo "test done"