From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7EE4C61DA4 for ; Sat, 28 Jan 2023 19:09:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233739AbjA1TJp (ORCPT ); Sat, 28 Jan 2023 14:09:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230012AbjA1TJo (ORCPT ); Sat, 28 Jan 2023 14:09:44 -0500 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id AE65E2310A; Sat, 28 Jan 2023 11:09:40 -0800 (PST) Date: Sat, 28 Jan 2023 20:09:36 +0100 From: Pablo Neira Ayuso To: Vlad Buslov Cc: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us, ozsh@nvidia.com, marcelo.leitner@gmail.com, simon.horman@corigine.com Subject: Re: [PATCH net-next v5 6/7] net/sched: act_ct: offload UDP NEW connections Message-ID: References: <20230127183845.597861-1-vladbu@nvidia.com> <20230127183845.597861-7-vladbu@nvidia.com> <87r0veejeb.fsf@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <87r0veejeb.fsf@nvidia.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sat, Jan 28, 2023 at 05:31:40PM +0200, Vlad Buslov wrote: > > On Sat 28 Jan 2023 at 16:26, Pablo Neira Ayuso wrote: > > Hi Vlad, > > > > On Fri, Jan 27, 2023 at 07:38:44PM +0100, Vlad Buslov wrote: > >> Modify the offload algorithm of UDP connections to the following: > >> > >> - Offload NEW connection as unidirectional. > >> > >> - When connection state changes to ESTABLISHED also update the hardware > >> flow. However, in order to prevent act_ct from spamming offload add wq for > >> every packet coming in reply direction in this state verify whether > >> connection has already been updated to ESTABLISHED in the drivers. If that > >> it the case, then skip flow_table and let conntrack handle such packets > >> which will also allow conntrack to potentially promote the connection to > >> ASSURED. > >> > >> - When connection state changes to ASSURED set the flow_table flow > >> NF_FLOW_HW_BIDIRECTIONAL flag which will cause refresh mechanism to offload > >> the reply direction. > >> > >> All other protocols have their offload algorithm preserved and are always > >> offloaded as bidirectional. > >> > >> Note that this change tries to minimize the load on flow_table add > >> workqueue. First, it tracks the last ctinfo that was offloaded by using new > >> flow 'ext_data' field and doesn't schedule the refresh for reply direction > >> packets when the offloads have already been updated with current ctinfo. > >> Second, when 'add' task executes on workqueue it always update the offload > >> with current flow state (by checking 'bidirectional' flow flag and > >> obtaining actual ctinfo/cookie through meta action instead of caching any > >> of these from the moment of scheduling the 'add' work) preventing the need > >> from scheduling more updates if state changed concurrently while the 'add' > >> work was pending on workqueue. > > > > Could you use a flag to achieve what you need instead of this ext_data > > field? Better this ext_data and the flag, I prefer the flags. > > Sure, np. Do you prefer the functionality to be offloaded to gc (as in > earlier versions of this series) or leverage 'refresh' code as in > versions 4-5? No, I prefer generic gc/refresh mechanism is not used for this. What I mean is: could you replace this new ->ext_data generic pointer by a flag to annotate what you need? Between this generic pointer and a flag, I prefer a flag.