From patchwork Thu Oct 8 19:34:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Han Zhou X-Patchwork-Id: 1378871 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=openvswitch.org (client-ip=140.211.166.133; helo=hemlock.osuosl.org; envelope-from=ovs-dev-bounces@openvswitch.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ovn.org Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4C6hGp0GC1z9sSn for ; Fri, 9 Oct 2020 06:34:26 +1100 (AEDT) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 16C0E87538; Thu, 8 Oct 2020 19:34:24 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YKUZ7ye30siY; Thu, 8 Oct 2020 19:34:23 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 5D62A8747C; Thu, 8 Oct 2020 19:34:23 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 48BBAC016F; Thu, 8 Oct 2020 19:34:23 +0000 (UTC) X-Original-To: dev@openvswitch.org Delivered-To: ovs-dev@lists.linuxfoundation.org Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 1F80EC0051 for ; Thu, 8 Oct 2020 19:34:22 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 1384786C77 for ; Thu, 8 Oct 2020 19:34:22 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id dD3o-QtAF5D3 for ; Thu, 8 Oct 2020 19:34:21 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from relay4-d.mail.gandi.net (relay4-d.mail.gandi.net [217.70.183.196]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 8A54186AA5 for ; Thu, 8 Oct 2020 19:34:20 +0000 (UTC) X-Originating-IP: 216.113.160.71 Received: from localhost.localdomain (unknown [216.113.160.71]) (Authenticated sender: hzhou@ovn.org) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id CA9E3E000D; Thu, 8 Oct 2020 19:34:17 +0000 (UTC) From: Han Zhou To: dev@openvswitch.org Date: Thu, 8 Oct 2020 12:34:02 -0700 Message-Id: <20201008193402.3786783-1-hzhou@ovn.org> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Cc: Han Zhou Subject: [ovs-dev] [PATCH ovn v2] ofctrl.c: Avoid repeatedly linking an installed flow and a desired flow. X-BeenThere: ovs-dev@openvswitch.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: ovs-dev-bounces@openvswitch.org Sender: "dev" In update_installed_flows_by_compare() there are two loops. The first loop iterates the installed flows and find its peer in desired flows to: 1. uninstall flows that are not needed anymore 2. update flows if needed At the same time, it links the desired flow found for the installed flow which also set the desired flow as the current active installed flow. The second loop iterates the desired flows and find its peer in installed flows to install missing flows. At the same time it will detect if there are conflict desired flows matching same installed flow then just link them. However, currently in the second loop, it blindly link the desired flows to the installed flows, without checking if it is already linked in the first loop. Lucky enough, this won't cause any real problem so far, because when there are conflict flows, the one found in the first loop will be set as active in the installed_flow, and in the function link_installed_to_desired() checks if it is already the active desired flow it just does nothing but return. However, the check in the link_installed_to_desired() is confusing because a desired_flow may be linked to the installed_flow already but not the active flow, and the check is insufficient. It should be rather an assertion and let the caller ensure that a pair of desired_flow and installed_flow is never linked twice. For the above reason, this patch does the following changes: 1. Removes the check in link_installed_to_desired() and convert it to an assert. 2. Before calling link_installed_to_desired() in the above mentioned loop, check if the desired flow is already installed. Signed-off-by: Han Zhou Acked-by: Dumitru Ceara --- v1 -> v2: Addresses Dumitru's comment. - Updated the check from checking if the desired flow is active to checking if the desired flow is linked to the installed flow. - Removed the first check that compares the desired flow with the active desired flow in link_installed_to_desired(). - Updated commit message. controller/ofctrl.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/controller/ofctrl.c b/controller/ofctrl.c index e725c003c..4425d9894 100644 --- a/controller/ofctrl.c +++ b/controller/ofctrl.c @@ -806,13 +806,18 @@ desired_flow_set_active(struct desired_flow *d) d->installed_flow->desired_flow = d; } +/* Adds the desired flow to the list of desired flows that have same match + * conditions as the installed flow. + * + * If the newly added desired flow is the first one in the list, it is also set + * as the active one. + * + * It is caller's responsibility to make sure the link between the pair didn't + * exist before. */ static void link_installed_to_desired(struct installed_flow *i, struct desired_flow *d) { - if (i->desired_flow == d) { - return; - } - + ovs_assert(i->desired_flow != d); if (ovs_list_is_empty(&i->desired_refs)) { ovs_assert(!i->desired_flow); i->desired_flow = d; @@ -1705,8 +1710,12 @@ update_installed_flows_by_compare(struct ovn_desired_flow_table *flow_table, /* Copy 'd' from 'flow_table' to installed_flows. */ i = installed_flow_dup(d); hmap_insert(&installed_flows, &i->match_hmap_node, i->flow.hash); + link_installed_to_desired(i, d); + } else if (!d->installed_flow) { + /* This is a desired_flow that conflicts with one installed + * previously but not linked yet. */ + link_installed_to_desired(i, d); } - link_installed_to_desired(i, d); } }