From patchwork Mon Jun 3 21:30:54 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Yang X-Patchwork-Id: 13684397 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8D7FF74297 for ; Mon, 3 Jun 2024 21:31:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717450307; cv=none; b=FnKzl1j2sttYnft/vuZfV5K0vIv1/VyDr3qwGcaC8QeasUGt0eMsRmVEGh0w2CQhH4+SUnTr1yaiZMMK2NOYRgbu7qFJ0fdbw9C9stXbhxCf2Qtbrp0+xMR1nFF1Q750bO/Nvy9VpMjJJ0rIQk+HlH2i85FZFSm64sXF/KoXWsw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717450307; c=relaxed/simple; bh=4L97r+0z1Zhfln/5re9uTaNvOFODzAqToKNu8CCh/ME=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Cc0sp7iw5B31jtIo50suOEtUf70QEKXhEtTPvakK4WqR+7MYWV+GbmjAD4TDFzHCkXulJqLJaS0W8lhqP7pWJZq801HHO/euFl0CbQU0l6ULYVaLNRF2ei9pd6/Vf4VD+6yqAxerJiMtVZ9A+7cDwAQEMLzx3iMGM3x14IlnobY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--yyd.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=b6UmMdV3; arc=none smtp.client-ip=209.85.219.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--yyd.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="b6UmMdV3" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-dfa744fe2f9so529598276.0 for ; Mon, 03 Jun 2024 14:31:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1717450304; x=1718055104; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=FoqpIvvH43hsGrd/sUpp3WJhNLZ4dhTt6GFW0BG1zpA=; b=b6UmMdV3GNkSWNXHW5iiOiSpmQpRAqwrtj/NNwzjY/bTqifzeRHjVHNUQFpUugLEKR 0Yu6xp4KRMZyql8B+E9hvqz6p35FQBkUtvckt414HjLhtw9XpyxAdmtv4FVCDwoKlW3g KlPJlmG2GamRqYScUCahAdUpOsRRVtl33js9l6zxGRzZDcvdWgnWofzxeVdfo3+UbArT KmqGFUkLLEvNgmbJr098K82oEV59B0fF5I+UDFzoO33qHLH+7YC23oKaDstEuveicOzf 5KDG138tE2M23tGgGgK3BUO2jkPn+wNlqBhALbkgMD27HECa2FUNMhhV+Sc4GjMqHHc9 Aa7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717450304; x=1718055104; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=FoqpIvvH43hsGrd/sUpp3WJhNLZ4dhTt6GFW0BG1zpA=; b=LhvLiJMSPoTVIS3yaavlTb4gL43ZfybLAKq8gnIrRSTo1AfprpYiLNqb8VBolegRrg gBWiePM6+7y30OVdIkZKVAEjAhfuGMQgx4OPQixsNmQ7fHRK/hGDyI9CeeqL02YR0jV/ fCAfGFXCLd5hOpOyMOQoHYizBRnYsJR8wwgZi5XuzQdfeJE73aD0/OIZTCSCAOQqmTix PA+B9OOzKfcOR+zibwxFBwYEq9S5zgktwA/XZ9v0Fcj9YqcETPuESuUh3GTEeXzFQSKu 3phZ5lAvZDS/t3jcEP/tHL14aJ2DN8XwTZpYHybRd5Ek3DFmiVXNbd1r6coMxD6bJyZw ubgg== X-Gm-Message-State: AOJu0YzWJnd5j/7iwLSKCAVOvMW1KO8mcKjtYI2I+oIf2j0aDYsWsl6h zJdCG0a/B8vz7ECJZ8BzdRD/jc6le5wEKGxQNi16V197X5XFzgkwu8WQ5RKuKZFmEA== X-Google-Smtp-Source: AGHT+IE0GSgQrvLtbwPA0JDIm3TaFTAPDovIvVdJbtxQaKwx+TKIna9/Ji0U+iGABY2M91kMzfTEIoI= X-Received: from yyd.c.googlers.com ([fda3:e722:ac3:cc00:dc:567e:c0a8:13c9]) (user=yyd job=sendgmr) by 2002:a05:6902:708:b0:df7:9609:4ce2 with SMTP id 3f1490d57ef6-dfa73d8da89mr800429276.8.1717450304576; Mon, 03 Jun 2024 14:31:44 -0700 (PDT) Date: Mon, 3 Jun 2024 21:30:54 +0000 In-Reply-To: <20240603213054.3883725-1-yyd@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240603213054.3883725-1-yyd@google.com> X-Mailer: git-send-email 2.45.1.288.g0e0cd299f1-goog Message-ID: <20240603213054.3883725-3-yyd@google.com> Subject: [PATCH net-next v3 2/2] tcp: add sysctl_tcp_rto_min_us From: Kevin Yang To: David Miller , Eric Dumazet , Jakub Kicinski Cc: netdev@vger.kernel.org, ncardwell@google.com, ycheng@google.com, kerneljasonxing@gmail.com, pabeni@redhat.com, tonylu@linux.alibaba.com, horms@kernel.org, David.Laight@aculab.com, Kevin Yang X-Patchwork-Delegate: kuba@kernel.org Adding a sysctl knob to allow user to specify a default rto_min at socket init time, other than using the hard coded 200ms default rto_min. Note that the rto_min route option has the highest precedence for configuring this setting, followed by the TCP_BPF_RTO_MIN socket option, followed by the tcp_rto_min_us sysctl. Signed-off-by: Kevin Yang Reviewed-by: Neal Cardwell Reviewed-by: Yuchung Cheng Reviewed-by: Eric Dumazet Reviewed-by: Tony Lu Reviewed-by: Jakub Kicinski --- Documentation/networking/ip-sysctl.rst | 13 +++++++++++++ include/net/netns/ipv4.h | 1 + net/ipv4/sysctl_net_ipv4.c | 8 ++++++++ net/ipv4/tcp.c | 4 +++- net/ipv4/tcp_ipv4.c | 1 + 5 files changed, 26 insertions(+), 1 deletion(-) diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index bd50df6a5a42..6e99eccdb837 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -1196,6 +1196,19 @@ tcp_pingpong_thresh - INTEGER Default: 1 +tcp_rto_min_us - INTEGER + Minimal TCP retransmission timeout (in microseconds). Note that the + rto_min route option has the highest precedence for configuring this + setting, followed by the TCP_BPF_RTO_MIN socket option, followed by + this tcp_rto_min_us sysctl. + + The recommended practice is to use a value less or equal to 200000 + microseconds. + + Possible Values: 1 - INT_MAX + + Default: 200000 + UDP variables ============= diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index c356c458b340..a91bb971f901 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -170,6 +170,7 @@ struct netns_ipv4 { u8 sysctl_tcp_sack; u8 sysctl_tcp_window_scaling; u8 sysctl_tcp_timestamps; + int sysctl_tcp_rto_min_us; u8 sysctl_tcp_recovery; u8 sysctl_tcp_thin_linear_timeouts; u8 sysctl_tcp_slow_start_after_idle; diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index d7892f34a15b..bb64c0ef092d 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -1503,6 +1503,14 @@ static struct ctl_table ipv4_net_table[] = { .proc_handler = proc_dou8vec_minmax, .extra1 = SYSCTL_ONE, }, + { + .procname = "tcp_rto_min_us", + .data = &init_net.ipv4.sysctl_tcp_rto_min_us, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ONE, + }, }; static __net_init int ipv4_sysctl_init_net(struct net *net) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 5fa68e7f6ddb..fa43aaacd92b 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -420,6 +420,7 @@ void tcp_init_sock(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); + int rto_min_us; tp->out_of_order_queue = RB_ROOT; sk->tcp_rtx_queue = RB_ROOT; @@ -428,7 +429,8 @@ void tcp_init_sock(struct sock *sk) INIT_LIST_HEAD(&tp->tsorted_sent_queue); icsk->icsk_rto = TCP_TIMEOUT_INIT; - icsk->icsk_rto_min = TCP_RTO_MIN; + rto_min_us = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rto_min_us); + icsk->icsk_rto_min = usecs_to_jiffies(rto_min_us); icsk->icsk_delack_max = TCP_DELACK_MAX; tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT); minmax_reset(&tp->rtt_min, tcp_jiffies32, ~0U); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 041c7eda9abe..49a5e2c4ec18 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -3506,6 +3506,7 @@ static int __net_init tcp_sk_init(struct net *net) net->ipv4.sysctl_tcp_shrink_window = 0; net->ipv4.sysctl_tcp_pingpong_thresh = 1; + net->ipv4.sysctl_tcp_rto_min_us = jiffies_to_usecs(TCP_RTO_MIN); return 0; }