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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 BD6AEC2D0D2 for ; Fri, 20 Dec 2019 07:20:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 951BB24680 for ; Fri, 20 Dec 2019 07:20:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727201AbfLTHUv (ORCPT ); Fri, 20 Dec 2019 02:20:51 -0500 Received: from mga04.intel.com ([192.55.52.120]:39708 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725965AbfLTHUv (ORCPT ); Fri, 20 Dec 2019 02:20:51 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Dec 2019 23:20:50 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,335,1571727600"; d="scan'208";a="241419924" Received: from cbenkese-mobl1.ger.corp.intel.com (HELO btopel-mobl.ger.intel.com) ([10.249.34.236]) by fmsmga004.fm.intel.com with ESMTP; 19 Dec 2019 23:20:49 -0800 Subject: Re: [PATCH bpf-next] libbpf: fix AF_XDP helper program to support kernels without the JMP32 eBPF instruction class To: Alex Forster , Alexei Starovoitov Cc: Network Development , Alexei Starovoitov , "Karlsson, Magnus" , bpf References: <20191219201601.7378-1-aforster@cloudflare.com> From: =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= Message-ID: Date: Fri, 20 Dec 2019 08:20:48 +0100 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: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2019-12-19 23:29, Alex Forster wrote: >> I though af_xdp landed after jmp32 ? > > They were indeed pretty close together, but AF_XDP became usable in > late 2018 with either 4.18 or 4.19. JMP32 landed in early 2019 with > 5.1. > Correct, but is anyone really using AF_XDP pre-5.1? The rationale for doing JMP32: https://lore.kernel.org/bpf/87v9sip0i8.fsf@toke.dk/ I think going forward, a route where different AF_XDP programs is loaded based on what currently running kernel supports. "Every s^Hcycle is sacred", and we're actually paying for the extra checks. Then again, failing to load is still pretty bad. :-) Thanks for fixing this. Acked-by: Björn Töpel > Alex Forster >