From nobody Wed Sep 17 19:38:43 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BE5D527CCC7 for ; Tue, 29 Jul 2025 08:22:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753777364; cv=none; b=QNA/tdDBccA0Eu5/oMkp9tEKzLdobuJuZUSgBVz/S46mz80/7uyNZwowKNrC7NwELlqIfxSHC3c+q0keH813nsUoE7+k+FI0TBF3fcbsEvI5MAMDJqVn0uyNy0Hc3GWWO7bwlf6wBWAVs1PCPvBYXh7ti289TfZu2NQ8wag1nNo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753777364; c=relaxed/simple; bh=4SLld/O3NxZJuOjnaHqLXMNohhdDfaiwVl9qwASiMuQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eAXHEX1qbJ4jAXmnB1hWvlkvufG62QgO8+wqC5JJKTAesRfkmm3nOegZmlNNVt0VKuHtO6JePY2EB14379aSLQT6lQttNXrVFY1pbXgMvp28p2ifgyRcEQExX3pFDLh4k6CyRT2Zsx2TROKwy1UXQOE6Y8JOay5XnZkjBm9Tka8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WkLnbR3e; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WkLnbR3e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E24BC4CEF8; Tue, 29 Jul 2025 08:22:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753777364; bh=4SLld/O3NxZJuOjnaHqLXMNohhdDfaiwVl9qwASiMuQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WkLnbR3ea7meLhiQpU5kiL/W64ZZ1cEQ6IpL0kG3qQPRiO7vay3skAuVr6tHgFglq bhgu7V7QaGUuQ9gY0Tp42rED73iH9iuacdLdZcFPpMPIwGwRNxzjWyI+YXcrX9fgvA irtnxatNp7P4zaEz8QA5hhIcoxfciNEAs5oUtSkfh9lLYi68a58Z3hBbvUuFbePiAg 8JXGDWVJ7lWNDmqLV0sjpysS/IJirZySJxxu/k4UA/8ry3KPicOT4wroSJ+uYO1off w4XjJzuJkV29B6AFP4lhGN4Ympc25sYbSaA4S/LocQBPwUeinbjY6pEKeB66gjxDdu wN8wDI2GnNomA== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next 2/3] mptcp: make ADD_ADDR timeout adaptive to subflow RTT Date: Tue, 29 Jul 2025 16:22:32 +0800 Message-ID: <12b2e330c05554b030615375f82b5af1fb7b8289.1753777199.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.48.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang This patch makes the ADD_ADDR retransmission timeout adaptive by using the maximum subflow RTT, while still capping it at the configured max value (add_addr_timeout_max). This improves responsiveness when establishing new subflows. The change: - Adds mptcp_get_add_addr_timeout() helper - Uses subflow RTT when available - Falls back to max timeout otherwise Signed-off-by: Geliang Tang --- net/mptcp/pm.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 40e8ebe566e5..bf4d92293e1e 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -268,6 +268,27 @@ int mptcp_pm_mp_prio_send_ack(struct mptcp_sock *msk, return -EINVAL; } =20 +static unsigned int mptcp_get_add_addr_timeout(struct mptcp_sock *msk, + const struct net *net) +{ + unsigned int timeout =3D mptcp_get_add_addr_timeout_max(net); + struct mptcp_subflow_context *subflow; + unsigned int srtt_us =3D 0; + + mptcp_for_each_subflow(msk, subflow) { + struct sock *ssk =3D mptcp_subflow_tcp_sock(subflow); + struct tcp_sock *tp =3D tcp_sk(ssk); + + if (srtt_us < tp->srtt_us) + srtt_us =3D tp->srtt_us; + } + + if (srtt_us && srtt_us < timeout) + timeout =3D srtt_us; + + return timeout; +} + static void mptcp_pm_add_timer(struct timer_list *timer) { struct mptcp_pm_add_entry *entry =3D timer_container_of(entry, timer, @@ -302,7 +323,7 @@ static void mptcp_pm_add_timer(struct timer_list *timer) =20 if (entry->retrans_times < ADD_ADDR_RETRANS_MAX) sk_reset_timer(sk, timer, - jiffies + mptcp_get_add_addr_timeout_max(sock_net(sk))); + jiffies + mptcp_get_add_addr_timeout(msk, sock_net(sk))); =20 spin_unlock_bh(&msk->pm.lock); =20 @@ -354,7 +375,7 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk, return false; =20 sk_reset_timer(sk, &add_entry->add_timer, - jiffies + mptcp_get_add_addr_timeout_max(net)); + jiffies + mptcp_get_add_addr_timeout(msk, net)); return true; } =20 @@ -370,7 +391,7 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk, =20 timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0); sk_reset_timer(sk, &add_entry->add_timer, - jiffies + mptcp_get_add_addr_timeout_max(net)); + jiffies + mptcp_get_add_addr_timeout(msk, net)); =20 return true; } --=20 2.48.1