From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) (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 EA940D50F for ; Wed, 30 Nov 2022 23:16:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669850196; x=1701386196; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=JmOOHyBP5NhEfLW98K/P9P+oKNkVzNFjmBdsfGSkidw=; b=fSsdgfUnIfsnNWeMz3Cp2MYW6mTZCMa/aLnciRPTwdgX7t50dXwk1uQu 6heakbsAHpHn41HryuB7VlQiJdPatjSVgwyAoc18NnAdN9vQY4ok+XfYr jRb2o3iGOHfSA5WM2coenQPlNYX6DAiHV9LLpcuivli/AABv0R4j6ife1 EdppumsXlw1Kf6RTMR6dbK7jB8lZxtPyi1npYhWWDygBW940ul3s4xHYn XwAz8nBDeqJ4uEht6HfqsDc4p7/rT4UAHZR6paVnwmvP6lfP5T5P8d2Cj 0UcnWin1TMFonnjdfOQTZ5tcH1gQHgwo0FQf5zvm6aaAKu404ZfzqcWSf g==; X-IronPort-AV: E=McAfee;i="6500,9779,10547"; a="401811096" X-IronPort-AV: E=Sophos;i="5.96,207,1665471600"; d="scan'208";a="401811096" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Nov 2022 15:16:36 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10547"; a="638173930" X-IronPort-AV: E=Sophos;i="5.96,207,1665471600"; d="scan'208";a="638173930" Received: from cman-mobl2.amr.corp.intel.com ([10.212.228.45]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Nov 2022 15:16:36 -0800 Date: Wed, 30 Nov 2022 15:16:35 -0800 (PST) From: Mat Martineau To: Geliang Tang cc: mptcp@lists.linux.dev Subject: Re: [PATCH mptcp-next v21 2/7] mptcp: use get_send wrapper In-Reply-To: Message-ID: <6fedab02-8371-fab5-5dbf-7cd2602f9053@linux.intel.com> References: 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 Mon, 28 Nov 2022, Geliang Tang wrote: > This patch adds 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. > > Move sock_owned_by_me() check and fallback check into get_send() wrapper > from mptcp_subflow_get_send(). > > 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 | 118 ++++++++++++++++++++++++++----------------- > net/mptcp/sched.c | 13 +++++ > 2 files changed, 84 insertions(+), 47 deletions(-) > > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index d8ad68dd504a..65eaf59c9a6f 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -1408,15 +1408,6 @@ 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; > @@ -1563,47 +1554,58 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags) > { > struct sock *prev_ssk = NULL, *ssk = NULL; > struct mptcp_sock *msk = mptcp_sk(sk); > + struct mptcp_subflow_context *subflow; > struct mptcp_sendmsg_info info = { > .flags = flags, > }; > bool do_check_data_fin = false; > + bool err = false; The code below will still quit the "while (mptcp send_head() && !err)" loop if the previous iteration had an error on one subflow (even if multiple subflows were scheduled and there were successful sends). I suggest removing the "bool err" and instead add int push_count = -1; (more info below) > > - while (mptcp_send_head(sk)) { > + while (mptcp_send_head(sk) && !err) { Change to while (mptcp_send_head(sk) && (push_count == 0)) { > 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); add: push_count = 0; > + mptcp_for_each_subflow(msk, subflow) { > + if (READ_ONCE(subflow->scheduled)) { > + prev_ssk = ssk; > + ssk = mptcp_subflow_tcp_sock(subflow); > > - ret = __subflow_push_pending(sk, ssk, &info); > - if (ret <= 0) { > - if (ret == -EAGAIN) > - continue; > - mptcp_push_release(ssk, &info); > - goto out; > + if (ssk != prev_ssk) { > + /* First check. If the ssk has changed since > + * the last round, release prev_ssk > + */ > + if (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 > + */ > + lock_sock(ssk); > + } > + add: push_count++; > + ret = __subflow_push_pending(sk, ssk, &info); > + if (ret <= 0) { > + if (ret != -EAGAIN || > + (1 << ssk->sk_state) & > + (TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | TCPF_CLOSE)) > + err = true; replace with: push_count--; This way push_count will be a positive number at the end of the loop iteration if any __subflow_push_pending() calls succeeded, and the loop will continue sending on the working subflow(s). - Mat > + continue; > + } > + 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); > @@ -1614,33 +1616,55 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags) > static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk, bool first) > { > struct mptcp_sock *msk = mptcp_sk(sk); > + struct mptcp_subflow_context *subflow; > struct mptcp_sendmsg_info info = { > .data_lock_held = true, > }; > - struct sock *xmit_ssk; > + bool err = false; > int copied = 0; > > info.flags = 0; > - while (mptcp_send_head(sk)) { > + while (mptcp_send_head(sk) && !err) { > int ret = 0; > > /* 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); > - goto out; > + if (first) { > + ret = __subflow_push_pending(sk, ssk, &info); > + first = false; > + if (ret <= 0) > + break; > + copied += ret; > + msk->last_snd = ssk; > + continue; > } > > - ret = __subflow_push_pending(sk, ssk, &info); > - first = false; > - if (ret <= 0) > - break; > - copied += ret; > + if (mptcp_sched_get_send(msk)) > + goto out; > + > + 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) { > + err = true; > + continue; > + } > + copied += ret; > + msk->last_snd = ssk; > + mptcp_subflow_set_scheduled(subflow, false); > + } > + } > } > > out: > diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c > index c4006f142f10..18518a81afb3 100644 > --- a/net/mptcp/sched.c > +++ b/net/mptcp/sched.c > @@ -118,6 +118,19 @@ int mptcp_sched_get_send(struct mptcp_sock *msk) > struct mptcp_subflow_context *subflow; > struct mptcp_sched_data data; > > + sock_owned_by_me((const struct sock *)msk); > + > + /* 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; > + } > + > mptcp_for_each_subflow(msk, subflow) { > if (READ_ONCE(subflow->scheduled)) > return 0; > -- > 2.35.3 > > > -- Mat Martineau Intel