From nobody Wed May 15 12:13:30 2024 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 E05D3DDA5 for ; Wed, 6 Mar 2024 02:55:39 +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=1709693740; cv=none; b=EU+DaLaI3sTp54oq8ToSCPXiEJLMw2iXN8KJzxu0yejPx4gh/hcb9RCc1natfHOgfZlD2HJAcHsTaJZUAsPBu5/EvMfhP92JUFn4FkN8mHXBJsU2M1NYZl3KDm5uSLbpF7hf5+D7De8obDZfnwwx9ToRXGEob9WwX/HTms3DMm4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709693740; c=relaxed/simple; bh=erewwXX/wc64vP41reoaW7Z+H31HaYmwJVYqTpwyPUc=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=gZ1w0IqsKSkLXFjBod2iLIlMFmj6VF8OlSB4ggHuaPIO+fhd9slW4yMBJtKe+hNvp1E586jkrKeaA+krwgWWZxS6oOLs6COzRliz+/P7SUtyyqLSI4vRzeRDzChcHm+0SMkNxX33kiPIzovy397iFfK16nvzgmfOcPpA79Kvm+Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ey4HKAeC; 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="Ey4HKAeC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49685C433F1; Wed, 6 Mar 2024 02:55:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709693739; bh=erewwXX/wc64vP41reoaW7Z+H31HaYmwJVYqTpwyPUc=; h=From:To:Cc:Subject:Date:From; b=Ey4HKAeCtiIQTj0wn+vjZl/D3F4lZ5u/EfM9q/TWk+gWLKgTTYrX07JWWCQyrZAZI c7+OA2XssaYwFz5z0TbzCFrZlaOpNUAasRvRbOmYOVCwxo8amaYp9fBXxjdDJDHC+f MqjcOFhDzDE/wXZ42sUzUOFJxbcmlqqT0UgyTmz3jgX9SOSbl4O6akVu+lbHrr4TLr lw5YKmVIpRVf7r9k79OzJM7VJXp5QNc6oD8VDu0+5WBwEdNw4A2eSh9pcLdcMga7Vs BxLzpvy7SftWCMda/uwn1fG3awr/jj6aCSa2r4SuPwMe2/0bv/0hsVM4QvAzO2vbJD NEamIJ3CNperQ== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH RFC] mptcp: react scheduler when subflow events pop up Date: Wed, 6 Mar 2024 10:55:33 +0800 Message-Id: <433320c3a9db77bea53a34fc9c43a3c7e3320399.1709693691.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.40.1 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 The current packet scheduler will not react by queuing more packets if some subflows only events are emitted, e.g. new TCP ACKs are received only acking things at TCP-level but not at MPTCP level. The scheduler should be called when such events happen. ack_update_msk() is invoked when an ACK is received, so it's the right place to call the scheduler by invoking __mptcp_check_push(). mptcp_subflow_timeout() is implemented to call the scheduler when a subflow timeout happens. But I'm not sure where is the right place to invoke it. I mean where is the right place when a RTO is fired. So I temporarily do it in mptcp_worker(). Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/343 Signed-off-by: Geliang Tang --- include/net/tcp.h | 3 +++ net/ipv4/tcp_timer.c | 6 +++--- net/mptcp/options.c | 1 + net/mptcp/protocol.c | 23 ++++++++++++++++++++++- net/mptcp/protocol.h | 1 + 5 files changed, 30 insertions(+), 4 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 6ae35199d3b3..431a23a8ebfa 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -347,6 +347,9 @@ void tcp_release_cb(struct sock *sk); void tcp_wfree(struct sk_buff *skb); void tcp_write_timer_handler(struct sock *sk); void tcp_delack_timer_handler(struct sock *sk); +bool retransmits_timed_out(struct sock *sk, + unsigned int boundary, + unsigned int timeout); int tcp_ioctl(struct sock *sk, int cmd, int *karg); enum skb_drop_reason tcp_rcv_state_process(struct sock *sk, struct sk_buff= *skb); void tcp_rcv_established(struct sock *sk, struct sk_buff *skb); diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index d1ad20ce1c8c..cfedafc4ca36 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -212,9 +212,9 @@ static unsigned int tcp_model_timeout(struct sock *sk, * after "boundary" unsuccessful, exponentially backed-off * retransmissions with an initial RTO of TCP_RTO_MIN. */ -static bool retransmits_timed_out(struct sock *sk, - unsigned int boundary, - unsigned int timeout) +bool retransmits_timed_out(struct sock *sk, + unsigned int boundary, + unsigned int timeout) { struct tcp_sock *tp =3D tcp_sk(sk); unsigned int start_ts, delta; diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 5926955625cf..4b091d3bce00 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -1069,6 +1069,7 @@ static void ack_update_msk(struct mptcp_sock *msk, __mptcp_snd_una_update(msk, new_snd_una); __mptcp_data_acked(sk); } + __mptcp_check_push(sk, ssk); mptcp_data_unlock(sk); =20 trace_ack_update_msk(mp_opt->data_ack, diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index cdf9ec67795e..c935f6a7adb0 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -486,6 +486,26 @@ static long mptcp_timeout_from_subflow(const struct mp= tcp_subflow_context *subfl inet_csk(ssk)->icsk_timeout - jiffies : 0; } =20 +static void __mptcp_subflow_timeout(struct sock *sk, struct sock *ssk, lon= g tout) +{ + unsigned int boundary =3D READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_retries= 1) + 1; + + if (retransmits_timed_out(ssk, boundary, tout)) + __mptcp_check_push(sk, ssk); +} + +static void mptcp_subflow_timeout(struct sock *sk) +{ + struct mptcp_subflow_context *subflow; + + mptcp_for_each_subflow(mptcp_sk(sk), subflow) { + struct sock *ssk =3D mptcp_subflow_tcp_sock(subflow); + long tout =3D mptcp_timeout_from_subflow(subflow); + + __mptcp_subflow_timeout(sk, ssk, tout); + } +} + void mptcp_set_timeout(struct sock *sk) { struct mptcp_subflow_context *subflow; @@ -1624,7 +1644,7 @@ void __mptcp_push_pending(struct sock *sk, unsigned i= nt flags) mptcp_check_send_data_fin(sk); } =20 -static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk= , bool first) +void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk, bool = first) { struct mptcp_sock *msk =3D mptcp_sk(sk); struct mptcp_sendmsg_info info =3D { @@ -2741,6 +2761,7 @@ static void mptcp_worker(struct work_struct *work) mptcp_check_fastclose(msk); =20 mptcp_pm_nl_work(msk); + mptcp_subflow_timeout(sk); =20 mptcp_check_send_data_fin(sk); mptcp_check_data_fin_ack(sk); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 7905783c95e4..f4b75be49690 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -656,6 +656,7 @@ void mptcp_close_ssk(struct sock *sk, struct sock *ssk, void __mptcp_subflow_send_ack(struct sock *ssk); void mptcp_subflow_reset(struct sock *ssk); void mptcp_subflow_queue_clean(struct sock *sk, struct sock *ssk); +void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk, bool = first); void mptcp_sock_graft(struct sock *sk, struct socket *parent); u64 mptcp_wnd_end(const struct mptcp_sock *msk); void mptcp_set_timeout(struct sock *sk); --=20 2.40.1