From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0EA4B569D for ; Fri, 23 Jun 2023 10:16:16 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFC0E189 for ; Fri, 23 Jun 2023 03:16:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1687515375; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Wbb+i4KWtaqSPWTYfrigxDvU8UMGL/SwUc27+u/CQjI=; b=SgRDYpbw6IawB2SbUboXTCTv4PzRA2ANS8DyjUKQoHqqhAtYQsnXytvbumqZv38UK08NKM Cet8leT2BPrgqUE8NQB0+LnFZ3yMo8rxsv2A0oyqtLjWeJhzSM799R/xu5MhYHMX1Y2bpM obIPxyuVQVE8owpRKWSEnSt7t1xC1DA= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-543-wyItmgr1PN2xwLwrNln44g-1; Fri, 23 Jun 2023 06:16:12 -0400 X-MC-Unique: wyItmgr1PN2xwLwrNln44g-1 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-3f810b4903fso3694275e9.2 for ; Fri, 23 Jun 2023 03:16:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687515371; x=1690107371; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Wbb+i4KWtaqSPWTYfrigxDvU8UMGL/SwUc27+u/CQjI=; b=dXObwF3/5t1JK6I7vViSjLlymIp+bsjGUEZEXy6QRC2lCBkNyXFF+rMtDYcljIW+kT 0TPcUkMUPvwUnRTVj9s+mGnq73Rdz7ETWxhgRUyZvedplS+ttPDN7dXtErImwk2rlKZd HkHV6IeeSKo6AwpsjzTXamHfhyeXItY6RCzbBXxQ6oCmZvjvF101AEpPqSd3zFNYlWXg FCo40YnrB2NhVvu0HDbqpHiZWul9d6ty2i03dS2HTAVpgoVlYEhykxMaR9TT0SGgHYNa KIYyZRyCfa76SD/zsX1CjWneAhJaTsAgjMo+CSYYk3e7gTabOIGlRnkF3k027XTaJW4W XzRg== X-Gm-Message-State: AC+VfDyCwylY6nbA/PGEjMy6X61v2TdGtpa6oYHwNrB6xsN8lGQbni1F h/qHcy6tVYwLcBahLTX4lV3Y9++dvxASw2ns/JUqZ/i4pMRX1u6GhQLT2nhDLJszNMmUlv7JqPU 7zkhTm7Zck5b+xonQ X-Received: by 2002:a1c:750a:0:b0:3f7:cb42:fa28 with SMTP id o10-20020a1c750a000000b003f7cb42fa28mr16958399wmc.28.1687515371583; Fri, 23 Jun 2023 03:16:11 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ6fJS9nJI4SwLbDjsqYFbuD3TUHJL0rCF1ImCa1c3AcxPaUTTkGAHJ3URCyVur3mmn7xeUjww== X-Received: by 2002:a1c:750a:0:b0:3f7:cb42:fa28 with SMTP id o10-20020a1c750a000000b003f7cb42fa28mr16958382wmc.28.1687515371255; Fri, 23 Jun 2023 03:16:11 -0700 (PDT) Received: from [192.168.0.12] ([78.18.22.70]) by smtp.gmail.com with ESMTPSA id y12-20020a05600c364c00b003f7f249e7dfsm1959206wmq.4.2023.06.23.03.16.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 23 Jun 2023 03:16:10 -0700 (PDT) Message-ID: <4c592016-5b5e-9670-2231-b44642091d46@redhat.com> Date: Fri, 23 Jun 2023 11:16:09 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [RFC bpf-next v2 11/11] net/mlx5e: Support TX timestamp metadata Content-Language: en-US To: Alexei Starovoitov , Stanislav Fomichev Cc: bpf , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Hao Luo , Jiri Olsa , Network Development , "Wiles, Keith" , Jesper Brouer References: <20230621170244.1283336-1-sdf@google.com> <20230621170244.1283336-12-sdf@google.com> <20230622195757.kmxqagulvu4mwhp6@macbook-pro-8.dhcp.thefacebook.com> From: Maryam Tahhan In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A, RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE, SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On 23/06/2023 03:35, Alexei Starovoitov wrote: > Why do you think so? > Who are those users? > I see your proposal and thumbs up from onlookers. > afaict there are zero users for rx side hw hints too. > >> the specs are >> not public; things can change depending on fw version/etc/etc. >> So the progs that touch raw descriptors are not the primary use-case. >> (that was the tl;dr for rx part, seems like it applies here?) >> >> Let's maybe discuss that mlx5 example? Are you proposing to do >> something along these lines? >> >> void mlx5e_devtx_submit(struct mlx5e_tx_wqe *wqe); >> void mlx5e_devtx_complete(struct mlx5_cqe64 *cqe); >> >> If yes, I'm missing how we define the common kfuncs in this case. The >> kfuncs need to have some common context. We're defining them with: >> bpf_devtx_(const struct devtx_frame *ctx); > I'm looking at xdp_metadata and wondering who's using it. > I haven't seen a single bug report. > No bugs means no one is using it. There is zero chance that we managed > to implement it bug-free on the first try. > So new tx side things look like a feature creep to me. > rx side is far from proven to be useful for anything. > Yet you want to add new things. > Hi folks We in CNDP (https://github.com/CloudNativeDataPlane/cndp) have been looking to use xdp_metadata to relay receive side offloads from the NIC to our AF_XDP applications. We see this is a key feature that is essential for the viability of AF_XDP in the real world. We would love to see something adopted for the TX side alongside what's on the RX side. We don't want to waste cycles do everything in software when the NIC HW supports many features that we need. Thank you Maryam