From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) (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 CC67E372 for ; Fri, 11 Nov 2022 01:04:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668128677; x=1699664677; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=uWjJaFjTfLedeDwcMzvEJH9VWbG2Gyts0RfkcH8gTLI=; b=QabJPjcC7/hrPs05ofiCLHqCLMxKehK2ia48W+4iVM39PzXYEfOuQP8h ymmEE4QLaeljZZCAxvGPRiRiHZHok9Ut/K5vB4RU1WvL5XZGayECT8oXX 8kYVhgeCQwxfWiH6oIjmjj8sHeUjg6uZZW7rgE8/yybSurGZW8vb7GUz0 eXpp8vpVJ2bNfhvzxyPXGEa4Z3qSQJZI9R0rKX5vGoKM4GcKnqgRBo5YI bDUEHSeVCETD6DNlfuYp1knx+8fEvaBOC0y6n/lYbPExcSIlJ5RB5qz4L 6pg/RMQugROP8LwE02UaulSyiDrtoht6eu4nowjT/Bx8eDel0+g9u7SJj w==; X-IronPort-AV: E=McAfee;i="6500,9779,10527"; a="373615899" X-IronPort-AV: E=Sophos;i="5.96,155,1665471600"; d="scan'208";a="373615899" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Nov 2022 17:04:35 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10527"; a="762493940" X-IronPort-AV: E=Sophos;i="5.96,155,1665471600"; d="scan'208";a="762493940" Received: from ssamaraj-mobl1.amr.corp.intel.com ([10.209.53.250]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Nov 2022 17:04:35 -0800 Date: Thu, 10 Nov 2022 17:04:35 -0800 (PST) From: Mat Martineau To: Geliang Tang cc: mptcp@lists.linux.dev Subject: Re: [PATCH mptcp-next v18 10/15] mptcp: use get_send wrapper In-Reply-To: <262f6ec0dfa2ffba15899460df4676dc15d1bd62.1667897099.git.geliang.tang@suse.com> Message-ID: References: <262f6ec0dfa2ffba15899460df4676dc15d1bd62.1667897099.git.geliang.tang@suse.com> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed On Tue, 8 Nov 2022, Geliang Tang wrote: > This patch defines the packet scheduler wrapper mptcp_sched_get_send(), > invoke data_init() and get_subflow() of msk->sched in it. > > Set data->reinject to false in mptcp_sched_get_send(). If msk->sched is > NULL, use default functions mptcp_subflow_get_send() to send data. > > Move sock_owned_by_me() check and fallback check into the wrapper from > mptcp_subflow_get_send(). > > Add the multiple subflows support for __mptcp_push_pending() and > __mptcp_subflow_push_pending(). Use get_send() wrapper instead of > mptcp_subflow_get_send() in them. > > Check the subflow scheduled flags to test which subflow or subflows are > picked by the scheduler, use them to send data. > > This commit allows the scheduler to set the subflow->scheduled bit in > multiple subflows, but it does not allow for sending redundant data. > Multiple scheduled subflows will send sequential data on each subflow. > > Signed-off-by: Geliang Tang > --- > net/mptcp/protocol.c | 131 ++++++++++++++++++++++++++++--------------- > net/mptcp/protocol.h | 2 + > net/mptcp/sched.c | 37 ++++++++++++ > 3 files changed, 124 insertions(+), 46 deletions(-) > > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index d7aaa49c64f4..5bcadb36b99b 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -1406,7 +1406,7 @@ bool mptcp_subflow_active(struct mptcp_subflow_context *subflow) > * returns the subflow that will transmit the next DSS > * additionally updates the rtx timeout > */ > -static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) > +struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) > { > struct subflow_send_info send_info[SSK_MODE_MAX]; > struct mptcp_subflow_context *subflow; > @@ -1417,15 +1417,6 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) > u64 linger_time; > long tout = 0; > > - sock_owned_by_me(sk); > - > - if (__mptcp_check_fallback(msk)) { > - if (!msk->first) > - return NULL; > - return __tcp_can_send(msk->first) && > - sk_stream_memory_free(msk->first) ? msk->first : NULL; > - } > - > /* pick the subflow with the lower wmem/wspace ratio */ > for (i = 0; i < SSK_MODE_MAX; ++i) { > send_info[i].ssk = NULL; > @@ -1577,42 +1568,58 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags) > }; > bool do_check_data_fin = false; > > +again: > while (mptcp_send_head(sk)) { > + struct mptcp_subflow_context *subflow, *last = NULL; > int ret = 0; > > - prev_ssk = ssk; > - ssk = mptcp_subflow_get_send(msk); > - > - /* First check. If the ssk has changed since > - * the last round, release prev_ssk > - */ > - if (ssk != prev_ssk && prev_ssk) > - mptcp_push_release(prev_ssk, &info); > - if (!ssk) > + if (mptcp_sched_get_send(msk)) > goto out; > > - /* Need to lock the new subflow only if different > - * from the previous one, otherwise we are still > - * helding the relevant lock > - */ > - if (ssk != prev_ssk) > - lock_sock(ssk); > + mptcp_for_each_subflow(msk, subflow) { > + if (READ_ONCE(subflow->scheduled)) > + last = subflow; > + } Since mptcp_sched_get_send() is always called right before this, the subflow->scheduled flags will always be set. Does the new code with 'last' work as expected if the mptcp_sched_get_send() call is skipped when an existing subflow->scheduled flag is found? That way the old flags will be used the first time through this loop. - Mat > > - ret = __subflow_push_pending(sk, ssk, &info); > - if (ret <= 0) { > - if (ret == -EAGAIN) > - continue; > - mptcp_push_release(ssk, &info); > - goto out; > + mptcp_for_each_subflow(msk, subflow) { > + if (READ_ONCE(subflow->scheduled)) { > + prev_ssk = ssk; > + ssk = mptcp_subflow_tcp_sock(subflow); > + > + /* First check. If the ssk has changed since > + * the last round, release prev_ssk > + */ > + if (ssk != prev_ssk && prev_ssk) > + mptcp_push_release(prev_ssk, &info); > + > + /* Need to lock the new subflow only if different > + * from the previous one, otherwise we are still > + * helding the relevant lock > + */ > + if (ssk != prev_ssk) > + lock_sock(ssk); > + > + ret = __subflow_push_pending(sk, ssk, &info); > + if (ret <= 0) { > + if (ret == -EAGAIN && > + inet_sk_state_load(ssk) != TCP_CLOSE) > + goto again; > + if (last && subflow != last) > + continue; > + goto out; > + } > + do_check_data_fin = true; > + msk->last_snd = ssk; > + mptcp_subflow_set_scheduled(subflow, false); > + } > } > - do_check_data_fin = true; > } > > +out: > /* at this point we held the socket lock for the last subflow we used */ > if (ssk) > mptcp_push_release(ssk, &info); > > -out: > /* ensure the rtx timer is running */ > if (!mptcp_timer_pending(sk)) > mptcp_reset_timer(sk); > @@ -1626,29 +1633,61 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk, bool > struct mptcp_sendmsg_info info = { > .data_lock_held = true, > }; > - struct sock *xmit_ssk; > int ret = 0; > > info.flags = 0; > +again: > while (mptcp_send_head(sk)) { > + struct mptcp_subflow_context *subflow, *last = NULL; > + > /* check for a different subflow usage only after > * spooling the first chunk of data > */ > - xmit_ssk = first ? ssk : mptcp_subflow_get_send(msk); > - if (!xmit_ssk) > - goto out; > - if (xmit_ssk != ssk) { > - mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk), > - MPTCP_DELEGATE_SEND); > + if (first) { > + ret = __subflow_push_pending(sk, ssk, &info); > + first = false; > + if (ret <= 0) { > + if (ret == -EAGAIN && > + inet_sk_state_load(ssk) != TCP_CLOSE) > + goto again; > + break; > + } > + msk->last_snd = ssk; > + continue; > + } > + > + if (mptcp_sched_get_send(msk)) > goto out; > + > + mptcp_for_each_subflow(msk, subflow) { > + if (READ_ONCE(subflow->scheduled)) > + last = subflow; > } > > - ret = __subflow_push_pending(sk, ssk, &info); > - first = false; > - if (ret <= 0) { > - if (ret == -EAGAIN) > - continue; > - break; > + mptcp_for_each_subflow(msk, subflow) { > + if (READ_ONCE(subflow->scheduled)) { > + struct sock *xmit_ssk = mptcp_subflow_tcp_sock(subflow); > + > + if (xmit_ssk != ssk) { > + mptcp_subflow_delegate(subflow, > + MPTCP_DELEGATE_SEND); > + msk->last_snd = ssk; > + mptcp_subflow_set_scheduled(subflow, false); > + goto out; > + } > + > + ret = __subflow_push_pending(sk, ssk, &info); > + if (ret <= 0) { > + if (ret == -EAGAIN && > + inet_sk_state_load(ssk) != TCP_CLOSE) > + goto again; > + if (last && subflow != last) > + continue; > + goto out; > + } > + msk->last_snd = ssk; > + mptcp_subflow_set_scheduled(subflow, false); > + } > } > } > > diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h > index e93d64217896..2bc0acf2d659 100644 > --- a/net/mptcp/protocol.h > +++ b/net/mptcp/protocol.h > @@ -640,6 +640,8 @@ int mptcp_init_sched(struct mptcp_sock *msk, > void mptcp_release_sched(struct mptcp_sock *msk); > void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow, > bool scheduled); > +struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk); > +int mptcp_sched_get_send(struct mptcp_sock *msk); > > static inline bool __tcp_can_send(const struct sock *ssk) > { > diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c > index 0d7c73e9562e..bc5d82300863 100644 > --- a/net/mptcp/sched.c > +++ b/net/mptcp/sched.c > @@ -112,3 +112,40 @@ void mptcp_sched_data_set_contexts(const struct mptcp_sock *msk, > for (; i < MPTCP_SUBFLOWS_MAX; i++) > data->contexts[i] = NULL; > } > + > +int mptcp_sched_get_send(struct mptcp_sock *msk) > +{ > + struct mptcp_subflow_context *subflow; > + struct mptcp_sched_data data; > + struct sock *ssk = NULL; > + > + sock_owned_by_me((const struct sock *)msk); > + > + mptcp_for_each_subflow(msk, subflow) { > + if (READ_ONCE(subflow->scheduled)) > + return 0; > + } > + > + /* the following check is moved out of mptcp_subflow_get_send */ > + if (__mptcp_check_fallback(msk)) { > + if (msk->first && > + __tcp_can_send(msk->first) && > + sk_stream_memory_free(msk->first)) { > + mptcp_subflow_set_scheduled(mptcp_subflow_ctx(msk->first), true); > + return 0; > + } > + return -EINVAL; > + } > + > + if (!msk->sched) { > + ssk = mptcp_subflow_get_send(msk); > + if (!ssk) > + return -EINVAL; > + mptcp_subflow_set_scheduled(mptcp_subflow_ctx(ssk), true); > + return 0; > + } > + > + data.reinject = false; > + msk->sched->data_init(msk, &data); > + return msk->sched->get_subflow(msk, &data); > +} > -- > 2.35.3 > > > -- Mat Martineau Intel