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=-5.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 987FEC4742C for ; Wed, 4 Nov 2020 01:40:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DC7A2242A for ; Wed, 4 Nov 2020 01:40:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SVgZCOZu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730510AbgKDBks (ORCPT ); Tue, 3 Nov 2020 20:40:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728567AbgKDBks (ORCPT ); Tue, 3 Nov 2020 20:40:48 -0500 Received: from mail-io1-xd36.google.com (mail-io1-xd36.google.com [IPv6:2607:f8b0:4864:20::d36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77306C061A4D; Tue, 3 Nov 2020 17:40:48 -0800 (PST) Received: by mail-io1-xd36.google.com with SMTP id o11so9289811ioo.11; Tue, 03 Nov 2020 17:40:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=5PXhtPDP8zBwGol0twdKLwlVKUnyORjj759fS8L0cL8=; b=SVgZCOZuQDiSMXV46BXv6oVu2NF3+Jc3waS7CUGkoqj5lBH8qSXozoGh6e3fp14Pp/ 7zNveyuU+Br2YEOMjxRef+rp8JgWuu82HotT7LprnZK9yf4y2fN2FL8z6U4IqDPMMogc WI7xQjsLEgGwAVB3kehMNVdQLmElVslT3J8E4sX9LowvVac3sNCibHQ67w/Fr2tP3Vp/ du37fNlS/ov8N3FHXyT68iCydlR0XOiXoU8IRUAvfl0IH7RqKv9/Tt7v5AQNrfAvMsSt h8AWkcGrikdi+1BLEITu/eVOrXK11vsWpc0pIaChuoGQKu4+s7d62J5k/w2ieFLIiHeV 21zg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=5PXhtPDP8zBwGol0twdKLwlVKUnyORjj759fS8L0cL8=; b=jwa6KXxWoOlh7Sv4cZwHShZMf7j342/u8BPVcb8O6ly5khwvgU3zRrThHkcZG4Xh0w qD4Bh4wuohyZBNiaUaoSiCvmjA5l41oLXtgqdkjYpfv8LjzzaJ2XVDZtyrfNO7eIY/Ni StT7lIJbEnKKjoTi/ysjkkog8/wNJZ87TTYJbTjBH9d9OsNtGgqShZO0UdquNhIrWHIv DYSDCwnNn1kHSYcsJ/J29WgSouuEM7+ci8vfLn8Fa2Q2HWuIXaf8lX/eyLFh+bf76WIo ldNh+teQSUCEEitIAxJ//knzr+xYoIAJ5IkQqhYslLZCDB2iTf+ofMzjycImrUGBJq/y uWVg== X-Gm-Message-State: AOAM533HjdZvP6bbln3nQBcUp6u0xglZeqrKgybI7NYNCGp+hHpuo/Wm xHxD+WHiR4nTGc11z+cSVAQ= X-Google-Smtp-Source: ABdhPJwI1cRc0z1QBpsrhAJ7Sy5pAxdJumP54YcdCaukup1VU2REueaQk692d7NS6ZkWx/vidfe4wQ== X-Received: by 2002:a02:cbde:: with SMTP id u30mr8557917jaq.69.1604454047867; Tue, 03 Nov 2020 17:40:47 -0800 (PST) Received: from Davids-MacBook-Pro.local ([2601:282:803:7700:def:1f9b:2059:ffac]) by smtp.googlemail.com with ESMTPSA id n28sm366580ila.52.2020.11.03.17.40.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 03 Nov 2020 17:40:47 -0800 (PST) Subject: Re: [PATCHv3 iproute2-next 0/5] iproute2: add libbpf support To: Alexei Starovoitov Cc: Daniel Borkmann , Andrii Nakryiko , Hangbin Liu , Stephen Hemminger , Alexei Starovoitov , Martin KaFai Lau , Song Liu , Yonghong Song , David Miller , Jesper Dangaard Brouer , Networking , bpf , Jiri Benc , Andrii Nakryiko , =?UTF-8?Q?Toke_H=c3=b8iland-J=c3=b8rgensen?= References: <20201028132529.3763875-1-haliu@redhat.com> <20201029151146.3810859-1-haliu@redhat.com> <646cdfd9-5d6a-730d-7b46-f2b13f9e9a41@gmail.com> <3306d19c-346d-fcbc-bd48-f141db26a2aa@gmail.com> <71af5d23-2303-d507-39b5-833dd6ea6a10@gmail.com> <20201103225554.pjyuuhdklj5idk3u@ast-mbp.dhcp.thefacebook.com> From: David Ahern Message-ID: Date: Tue, 3 Nov 2020 18:40:44 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <20201103225554.pjyuuhdklj5idk3u@ast-mbp.dhcp.thefacebook.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 11/3/20 3:55 PM, Alexei Starovoitov wrote: > The bpf support in "tc" command instead of being obviously old and obsolete > will be sort-of working with unpredictable delay between released kernel > and released iproute2 version. The iproute2 release that suppose to match kernel > release will be meaningless. iproute2, like all userspace commands, is written to an API and for well written APIs the commands should be backward and forward compatible across kernel versions. Kernel upgrades do not force an update of the entire ecosystem. New userspace on old kernels should again just work. New functionality in the new userpsace will not, but detection of that is a different problem and relies on kernel APIs doing proper data validation. > More so, the upgrade of shared libbpf.so can make older iproute2/tc to do > something new and unpredictable. How so? If libbpf is written against kernel APIs and properly versioned, it should just work. A new version of libbpf changes the .so version, so old commands will not load it.