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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DDB5FC433E1 for ; Fri, 14 Aug 2020 06:57:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA56820708 for ; Fri, 14 Aug 2020 06:57:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="YCQmGi4U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726193AbgHNG5C (ORCPT ); Fri, 14 Aug 2020 02:57:02 -0400 Received: from mail.zx2c4.com ([192.95.5.64]:33007 "EHLO mail.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726091AbgHNG5C (ORCPT ); Fri, 14 Aug 2020 02:57:02 -0400 Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 67478349 for ; Fri, 14 Aug 2020 06:31:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=mime-version :references:in-reply-to:from:date:message-id:subject:to:cc :content-type; s=mail; bh=QAi5ZfWxfb4Xzi8SgOxteUmhlNQ=; b=YCQmGi 4UYlALkG/fl0ofcAUOw/KbvtA9qrGEp5kxMvDyXhg5roMCOAQSYtH8vG2I0WLwU5 6nAz4pLqQUvs1H7YARBb9MN6aVh0mt2r5wsfvTkNL2ieV5HVaNKEo0TTgOF6jLKR UyI/TmyPFBaAM4+InIjTM8L6n9mjkbtavktU/ChlDSewcXL/m8O6Iqikv0JBWtP+ RY0wlTlzs1Eth2n10Mb1W/sy0anMlQLg9Q8Ut/R0BdvlzgRSz60bfvb4tLVoBRhw yE+m91QgioObFyxQarpzviMoKgo4XzXyGA2IiEhWJnnw+deS1aDKWCwHDgHZUh/p p2kndwbxIOtvCCJg== Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 2909e36d (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO) for ; Fri, 14 Aug 2020 06:31:23 +0000 (UTC) Received: by mail-io1-f49.google.com with SMTP id z6so9834484iow.6 for ; Thu, 13 Aug 2020 23:57:00 -0700 (PDT) X-Gm-Message-State: AOAM531FHuQCB7r73syGdLM9oFX76yTmv1O5j5MBn4HwyPjLK2VF5IoM 3Pcrq1NLzbimGW0+Lm6tgyVpXza3OaBTnWjyR4k= X-Google-Smtp-Source: ABdhPJwghdP1cc93FiGzF7DYV3YVBQ0OiOTLAXH2S4PepxFfqW7ynGBXvhpsIKs6LGxjAyaWlcHQtS1g8jZD8fBXoXY= X-Received: by 2002:a05:6638:1027:: with SMTP id n7mr1543520jan.86.1597388219934; Thu, 13 Aug 2020 23:56:59 -0700 (PDT) MIME-Version: 1.0 References: <20200813195816.67222-1-Jason@zx2c4.com> <20200813140152.1aab6068@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <20200813140152.1aab6068@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> From: "Jason A. Donenfeld" Date: Fri, 14 Aug 2020 08:56:48 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH net v4] net: xdp: account for layer 3 packets in generic skb handler To: Jakub Kicinski Cc: Netdev , Thomas Ptacek , Adhipati Blambangan , David Ahern , =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= , Alexei Starovoitov Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Aug 13, 2020 at 11:01 PM Jakub Kicinski wrote: > > I had originally dropped this patch, but the issue kept coming up in > > user reports, so here's a v4 of it. Testing of it is still rather slim, > > but hopefully that will change in the coming days. > > Here an alternative patch, untested: Funny. But come on now... Why would we want to deprive our users of system consistency? Doesn't it make sense to allow users to use the same code across interfaces? You actually want them to rewrite their code to use a totally different trigger point just because of some weird kernel internals between interfaces? Why not make XDP more useful and more generic across interfaces? It's very common for systems to be receiving packets with a heavy ethernet card from the current data center, in addition to receiving packets from a tunnel interface connected to a remote data center, with a need to run the same XDP program on both interfaces. Why not support that kind of simplicity? This is _actually_ something that's come up _repeatedly_. This is a real world need from real users who are doing real things. Why not help them? It's not at the expense of any formal consistency, or performance, or even semantic perfection. It costs very little to support these popular use cases. [FYI, there's one tweak I'd like to make, so I'll probably send v5 ~soon.] Jason