From patchwork Fri Mar 17 15:16:06 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Pfaff X-Patchwork-Id: 740351 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3vl87N70Hyz9s1h for ; Sat, 18 Mar 2017 02:16:16 +1100 (AEDT) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id AF206B44; Fri, 17 Mar 2017 15:16:14 +0000 (UTC) X-Original-To: dev@openvswitch.org Delivered-To: ovs-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 9FDE6899 for ; Fri, 17 Mar 2017 15:16:13 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 1C95314E for ; Fri, 17 Mar 2017 15:16:13 +0000 (UTC) Received: from mfilter26-d.gandi.net (mfilter26-d.gandi.net [217.70.178.154]) by relay5-d.mail.gandi.net (Postfix) with ESMTP id D88BB41C0A5; Fri, 17 Mar 2017 16:16:11 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at mfilter26-d.gandi.net Received: from relay5-d.mail.gandi.net ([IPv6:::ffff:217.70.183.197]) by mfilter26-d.gandi.net (mfilter26-d.gandi.net [::ffff:10.0.15.180]) (amavisd-new, port 10024) with ESMTP id vgEDTGdEW14W; Fri, 17 Mar 2017 16:16:10 +0100 (CET) X-Originating-IP: 173.228.112.115 Received: from sigabrt.gateway.sonic.net (173-228-112-115.dsl.dynamic.fusionbroadband.com [173.228.112.115]) (Authenticated sender: blp@ovn.org) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id 3F3B641C08B; Fri, 17 Mar 2017 16:16:08 +0100 (CET) From: Ben Pfaff To: dev@openvswitch.org Date: Fri, 17 Mar 2017 08:16:06 -0700 Message-Id: <20170317151606.31912-1-blp@ovn.org> X-Mailer: git-send-email 2.10.2 X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Ben Pfaff Subject: [ovs-dev] [PATCH] faq: Expand on answer about packet buffering removal. X-BeenThere: ovs-dev@openvswitch.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ovs-dev-bounces@openvswitch.org Errors-To: ovs-dev-bounces@openvswitch.org Signed-off-by: Ben Pfaff --- Documentation/faq/openflow.rst | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/Documentation/faq/openflow.rst b/Documentation/faq/openflow.rst index 376e64eb4482..214e38e6a9aa 100644 --- a/Documentation/faq/openflow.rst +++ b/Documentation/faq/openflow.rst @@ -462,6 +462,14 @@ What's going on? messages and will send an error response if any other value of this field is included in a "packet-out" or a "flow mod" sent by a controller. + Packet buffers have limited usefulness in any case. Table-miss packet-in + messages most commonly pass the first packet in a microflow to the OpenFlow + controller, which then sets up an OpenFlow flow that handles remaining + traffic in the microflow without further controller intervention. In such + a case, the packet that initiates the microflow is usually small, which + means that the switch sends the entire packet to the controller and the + buffer only saves a small number of bytes in the reverse direction. + Q: How does OVS divide flows among buckets in an OpenFlow "select" group? A: In Open vSwitch 2.3 and earlier, Open vSwitch used the destination