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 5F7BDC433F5 for ; Tue, 15 Mar 2022 10:29:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347078AbiCOKaz (ORCPT ); Tue, 15 Mar 2022 06:30:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345266AbiCOKay (ORCPT ); Tue, 15 Mar 2022 06:30:54 -0400 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D9DE949C95 for ; Tue, 15 Mar 2022 03:29:42 -0700 (PDT) Received: from netfilter.org (unknown [78.30.32.163]) by mail.netfilter.org (Postfix) with ESMTPSA id 9EE9160196; Tue, 15 Mar 2022 11:27:22 +0100 (CET) Date: Tue, 15 Mar 2022 11:29:38 +0100 From: Pablo Neira Ayuso To: Vlad Buslov Cc: netfilter-devel@vger.kernel.org, kadlec@netfilter.org, fw@strlen.de, ozsh@nvidia.com, paulb@nvidia.com Subject: Re: [PATCH net-next 8/8] netfilter: flowtable: add hardware offload tracepoints Message-ID: References: <20220222151003.2136934-1-vladbu@nvidia.com> <20220222151003.2136934-9-vladbu@nvidia.com> <877d8zue2n.fsf@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <877d8zue2n.fsf@nvidia.com> Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Sat, Mar 12, 2022 at 10:05:55PM +0200, Vlad Buslov wrote: > > On Mon 07 Mar 2022 at 23:49, Pablo Neira Ayuso wrote: > > On Tue, Feb 22, 2022 at 05:10:03PM +0200, Vlad Buslov wrote: > >> Add tracepoints to trace creation and start of execution of flowtable > >> hardware offload 'add', 'del' and 'stats' tasks. Move struct > >> flow_offload_work from source into header file to allow access to structure > >> fields from tracepoint code. > > > > This patch, I would prefer to keep it back and explore exposing trace > > infrastructure for the flowtable through netlink. > > > > What approach do you have in mind with netlink? I used tracepoints here > because they are: > > - Incur no performance penalty when disabled. > > - Handy to attach BPF programs to. > > According to my experience with optimizing TC control path parsing > Netlink is CPU-intensive. I am also not aware of mechanisms to leverage > it to attach BPF. Sure, no question tracing and introspection is useful. But could you use the generic workqueue trace points instead? This is adding tracing infrastructure for a very specific purpose, to inspect the workqueue behaviour for the flowtable. And I am not sure how you use this yet other than observing that the workqueue is coping with the workload?