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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,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 D3EC3C4742C for ; Tue, 10 Nov 2020 12:47:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78E54207D3 for ; Tue, 10 Nov 2020 12:47:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730488AbgKJMrn (ORCPT ); Tue, 10 Nov 2020 07:47:43 -0500 Received: from dispatch1-us1.ppe-hosted.com ([148.163.129.49]:52104 "EHLO dispatch1-us1.ppe-hosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726462AbgKJMrn (ORCPT ); Tue, 10 Nov 2020 07:47:43 -0500 Received: from mx1-us1.ppe-hosted.com (unknown [10.7.65.61]) by dispatch1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id 8502960090; Tue, 10 Nov 2020 12:47:42 +0000 (UTC) Received: from us4-mdac16-46.ut7.mdlocal (unknown [10.7.66.13]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id 835728009E; Tue, 10 Nov 2020 12:47:42 +0000 (UTC) X-Virus-Scanned: Proofpoint Essentials engine Received: from mx1-us1.ppe-hosted.com (unknown [10.7.65.91]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id ED16580056; Tue, 10 Nov 2020 12:47:41 +0000 (UTC) Received: from webmail.solarflare.com (uk.solarflare.com [193.34.186.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id 4D99CBC0061; Tue, 10 Nov 2020 12:47:41 +0000 (UTC) Received: from [10.17.20.203] (10.17.20.203) by ukex01.SolarFlarecom.com (10.17.10.4) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 10 Nov 2020 12:47:32 +0000 Subject: Re: [PATCHv3 iproute2-next 0/5] iproute2: add libbpf support To: Jamal Hadi Salim , David Ahern , Daniel Borkmann , Alexei Starovoitov , Hangbin Liu CC: Andrii Nakryiko , 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> <20201104021730.GK2408@dhcp-12-153.nay.redhat.com> <20201104031145.nmtggnzomfee4fma@ast-mbp.dhcp.thefacebook.com> <2e8ba0be-51bf-9060-e1f7-2148fbaf0f1d@iogearbox.net> <1118ef27-3302-d077-021a-43aa8d8f3ebb@mojatatu.com> From: Edward Cree Message-ID: <11c18a26-72af-2e0d-a411-3148cfbc91be@solarflare.com> Date: Tue, 10 Nov 2020 12:47:28 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <1118ef27-3302-d077-021a-43aa8d8f3ebb@mojatatu.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Content-Language: en-GB X-Originating-IP: [10.17.20.203] X-ClientProxiedBy: ocex03.SolarFlarecom.com (10.20.40.36) To ukex01.SolarFlarecom.com (10.17.10.4) X-TM-AS-Product-Ver: SMEX-12.5.0.1300-8.6.1012-25778.003 X-TM-AS-Result: No-7.626800-8.000000-10 X-TMASE-MatchedRID: 1GZI+iG+MtfmLzc6AOD8DfHkpkyUphL9mIYIWwCrtbDfUZT83lbkEBbC 99SYja1g08KOouRPweXpA9zAtoTtQbwGAZ9mF4+tbMGKOuLn5FU2vbWaKPnQ20+86maMM3aSoqR TS3ju9kjL1YnN80IdgfrX3HUSpSJtbWU+hmLYQb30VCHd+VQiHsuCYrT3WeZNI0YrtQLsSUx/HZ ivtns2jCoEdDLq/Jx9DebCA+2uaihMi6dAAjypoo6MisxJraxHZAGtCJE23YjlhO+RZsN0Zgzha 8w4PtmsDbQK46q0MoVIK8AsRmtEnbRnkHe8f3Wi1ilQ4KKAwrcfqkfNzTRFSkvEK4FMJdoqFxHJ /PgKcF7XbjtE3SWl31+24nCsUSFNjaPj0W1qn0Q7AFczfjr/7EBUz7fy5vxHDt1tO/HyQLI3c0D GoeWQNPu3cx2BXcvV7l6uq4rmU/w= X-TM-AS-User-Approved-Sender: Yes X-TM-AS-User-Blocked-Sender: No X-TMASE-Result: 10--7.626800-8.000000 X-TMASE-Version: SMEX-12.5.0.1300-8.6.1012-25778.003 X-MDID: 1605012462-t_ROz6fajzuV X-PPE-DISP: 1605012462;t_ROz6fajzuV Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 05/11/2020 14:05, Jamal Hadi Salim wrote: > On 2020-11-04 10:19 p.m., David Ahern wrote: > > [..] >> Similarly, it is not realistic or user friendly to *require* general >> Linux users to constantly chase latest versions of llvm, clang, dwarves, >> bcc, bpftool, libbpf, (I am sure I am missing more) > > 2cents feedback from a dabbler in ebpf on user experience: > > What David described above *has held me back*. If we're doing 2¢... I gave up on trying to keep ebpf_asmabreast  of all the latest BPF and BTF features quite some time ago, since  there was rarely any documentation and the specifications for BPF  elves were basically "whatever latest clang does". The bpf developers seem to have taken the position that since  they're in control of clang, libbpf and the kernel, they can make  their changes across all three and not bother with the specs that  would allow other toolchains to interoperate.  As a result of  which, that belief has now become true — while ebpf_asm will  still work for what it always did (simple XDP programs), it is  unlikely ever to gain CO-RE support so is no longer a live  alternative to clang for BPF in general. Of course the bpf developers are well within their rights to not  care about that.  But I think it illustrates why having to  interoperate with systems outside their control and mix-and-match  versioning of various components provides external discipline that  is sorely needed if the BPF ecosystem is to remain healthy. That is why I am opposed to iproute2 'vendoring' libbpf. -ed