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 6DC6DC43381 for ; Thu, 11 Mar 2021 07:00:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 299D864FD4 for ; Thu, 11 Mar 2021 07:00:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231411AbhCKHAW (ORCPT ); Thu, 11 Mar 2021 02:00:22 -0500 Received: from mga05.intel.com ([192.55.52.43]:27367 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229731AbhCKG7y (ORCPT ); Thu, 11 Mar 2021 01:59:54 -0500 IronPort-SDR: zEntlNvJppVsZhHetCbT3/ecJMa9qbOYPC8rBONy8qKdadmLJ1Rt/ldEfdyVNxGaYNk+rURefp eq2Y6vdFoegg== X-IronPort-AV: E=McAfee;i="6000,8403,9919"; a="273662898" X-IronPort-AV: E=Sophos;i="5.81,239,1610438400"; d="scan'208";a="273662898" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Mar 2021 22:59:54 -0800 IronPort-SDR: etC1/Qix5RDSZFoTajB90yb4CFzzecsx1G7yzSSOWXTlITDi7yEXly3N8mhF7SsKL8x0yc6CEx vAPpTUFpQw8A== X-IronPort-AV: E=Sophos;i="5.81,239,1610438400"; d="scan'208";a="410506705" Received: from eefimov-mobl.ger.corp.intel.com (HELO btopel-mobl.ger.intel.com) ([10.252.48.42]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Mar 2021 22:59:50 -0800 Subject: Re: [PATCH bpf-next 2/2] libbpf: xsk: move barriers from libbpf_util.h to xsk.h To: Jonathan Lemon , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= Cc: ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org, bpf@vger.kernel.org, andrii@kernel.org, magnus.karlsson@intel.com, maximmi@nvidia.com, ciara.loftus@intel.com References: <20210310080929.641212-1-bjorn.topel@gmail.com> <20210310080929.641212-3-bjorn.topel@gmail.com> <20210311000605.tuo7rg4b7keo76iy@bsd-mbp.dhcp.thefacebook.com> From: =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= Message-ID: <0535ce9f-0db6-40f7-e512-e327f6f54c35@intel.com> Date: Thu, 11 Mar 2021 07:59:46 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210311000605.tuo7rg4b7keo76iy@bsd-mbp.dhcp.thefacebook.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 2021-03-11 01:06, Jonathan Lemon wrote: > On Wed, Mar 10, 2021 at 09:09:29AM +0100, Björn Töpel wrote: >> From: Björn Töpel >> >> The only user of libbpf_util.h is xsk.h. Move the barriers to xsk.h, >> and remove libbpf_util.h. The barriers are used as an implementation >> detail, and should not be considered part of the stable API. > > Does that mean that anything else which uses the same type of > shared rings (bpf ringbuffer, io_uring, zctap) have to implement > the same primitives that xsk.h has? > Jonathan, there's a longer explanation on back-/forward-compatibility in the commit message [1]. Again, this is for the XDP socket rings, so I wont comment on the other rings. I would not assume compatibility between different rings (e.g. the bpf ringbuffer and XDP sockets rings), not even prior the barrier change. Björn [1] https://lore.kernel.org/bpf/20210305094113.413544-2-bjorn.topel@gmail.com/