From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 082431360 for ; Sat, 30 Jul 2022 06:32:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1659162737; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DfsgKzdz+D5utw8y0Fh2NPcNEdw9tmeOLIhg2N9F8bU=; b=WFGEfFGeBFaMMokAmRSfqy1cx0StS6s+YjgvxE1ZYeXodS3tH68bWXBWOXW7j3wWq3R6f2 GUCtaGyhrUkaZvABKaVul2V6lK0lDEwozT2Np8PxBjY6HntYvc9Nw5xyGS/xdwDUHti1p1 r1IvKfCc39c8HfMr2vSlgibKmyh1bEA= Received: from mail-ej1-f70.google.com (mail-ej1-f70.google.com [209.85.218.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-256-Eju4XkxrMtOMBLTjv0Lmww-1; Sat, 30 Jul 2022 02:32:15 -0400 X-MC-Unique: Eju4XkxrMtOMBLTjv0Lmww-1 Received: by mail-ej1-f70.google.com with SMTP id qb31-20020a1709077e9f00b007304bcf4181so43124ejc.19 for ; Fri, 29 Jul 2022 23:32:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=DfsgKzdz+D5utw8y0Fh2NPcNEdw9tmeOLIhg2N9F8bU=; b=6Bf9Ype2PDH4p9zs80qGYYGfEoV/iFfm1vrW3wEWQrTmy3cdQ7PC9Bwp+MecWtGmAi Sn7k+d7TdEQkJzC319t/9WS4jHVpvoa3CB73Mkh2IHdGKoaZC8w9HCrR0vdaMnFZlu1x 29ztmykgCCW+RZ+7vCeWZVbRSWyxS7f9V5Y+K6EgbWg/+Q9Qyap9qj0qAC2gmUCH+L+F ehKqapm731Ny3qjYteBXW7LG6km++KnTw4c0CmAPPD8wR+/DRNI7kVSx30vv+UtAUZZ+ DZ/BpraAom+WrigpTave/AkWSmXckjgGZevv7nAgpGFeTpgtQg07hINAcuxIw65aa4nB qMNA== X-Gm-Message-State: AJIora9fy23ofgCy9RJZHJme6X2fJ7xyBg+c4eOejZqrvc3EPJ2QweAR BzzF6WGGo1B1qR7WpX2hEtEEN3RJpzgZeTj18dYuiS61XUZXEvd45f7NJJdDCgBi9fEAtZsjrz5 EYnaKzNvIjWpAFOk= X-Received: by 2002:a17:907:c0d:b0:72b:d0b0:2b55 with SMTP id ga13-20020a1709070c0d00b0072bd0b02b55mr5369959ejc.110.1659162734515; Fri, 29 Jul 2022 23:32:14 -0700 (PDT) X-Google-Smtp-Source: AGRyM1tzQ0L8NJ6+UGjdTruHB+jaJIJpHYVclU5xzQfdQl8pqqlNJc9ve0CR8sLiCAKDezxsf9l/zA== X-Received: by 2002:a17:907:c0d:b0:72b:d0b0:2b55 with SMTP id ga13-20020a1709070c0d00b0072bd0b02b55mr5369949ejc.110.1659162734124; Fri, 29 Jul 2022 23:32:14 -0700 (PDT) Received: from gerbillo.redhat.com (146-241-118-222.dyn.eolo.it. [146.241.118.222]) by smtp.gmail.com with ESMTPSA id vj16-20020a170907131000b006fec27575f1sm2533032ejb.123.2022.07.29.23.32.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Jul 2022 23:32:13 -0700 (PDT) Message-ID: Subject: Re: [PATCH v2 mptcp-next 2/4] mptcp: more accurate receive buffer updates From: Paolo Abeni To: Mat Martineau Cc: mptcp@lists.linux.dev Date: Sat, 30 Jul 2022 08:32:12 +0200 In-Reply-To: <13f2141b-f22b-8e16-1c74-13453ad3dc45@linux.intel.com> References: <1da024c8ed9da4fcf78aa2d73e00c1f9e4d3e98f.1659117128.git.pabeni@redhat.com> <13f2141b-f22b-8e16-1c74-13453ad3dc45@linux.intel.com> User-Agent: Evolution 3.42.4 (3.42.4-2.fc35) Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pabeni@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit On Fri, 2022-07-29 at 16:01 -0700, Mat Martineau wrote: > On Fri, 29 Jul 2022, Paolo Abeni wrote: > > > Currently mptcp_cleanup_rbuf() makes a significant effort to avoid > > acquiring the subflow socket lock, estimating if the tcp level > > cleanup could actually send an ack. > > > > Such estimate is a bit rough when accounting for receive window > > change, as it consider the msk available buffer space instead > > of the announced mptcp-level window. > > > > Let's consider the announced window instead, mirroring closely > > the plain TCP implementation. We need to lockless access a bunch > > of additional, tcp fields. > > Hi Paolo - > > The code changes look good. For this last sentence above ("...lockless > access a bunch of ... tcp fields"), I only see access to msk->rcv_wnd_sent > and msk->ack_seq, and nothing obvious in the later commits. Could you > clarify? You are right, that comment is inaccurate. Is there from a previous internal version. I'll drop it in the next iteration. Thanks! Paolo