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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95DB5C53210 for ; Thu, 5 Jan 2023 01:17:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230227AbjAEBRk (ORCPT ); Wed, 4 Jan 2023 20:17:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54618 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229581AbjAEBRi (ORCPT ); Wed, 4 Jan 2023 20:17:38 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72D9133D6F; Wed, 4 Jan 2023 17:17:37 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 0FFA2B818F2; Thu, 5 Jan 2023 01:17:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD336C433D2; Thu, 5 Jan 2023 01:17:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1672881454; bh=ZThWZLGnE1uBHhW+ZPEz4zsyBO1cinSai+TYFDqiNKE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=HhmNSmtaFYtMpL+KciBrmZKHAcW0h26OcLTrQuvdSLw8aVo19W5sGjIrekJiXuX0p G5UhvbqZmxt8dKISeF4skF9nt2HzXGoM1xu5glo8OB2fjxbZM9u6v28nV0edbsUug9 VmVbHPvIsgbGxp73fCPGPpHQ/HNXYUxizqDV1054rrRIjp3gGMl751NCEob5DjxO/Y 8phSvt+uUIfyIFRVW7RadI5XEUqAf2gHDt3aJwn+PD/gxBp/5acpvseF/UB1DDnggM SQsuw64DB6CaM1/0ISwYZmg+42m54Y7xLMq9qXvDaFIIwZpVJApJ6cas18qdkkYep1 oPCed1EJYd7Uw== Date: Wed, 4 Jan 2023 17:17:33 -0800 From: Jakub Kicinski To: Toke =?UTF-8?B?SMO4aWxhbmQtSsO4cmdlbnNlbg==?= Cc: Lorenzo Bianconi , Tariq Toukan , Andy Gospodarek , ast@kernel.org, daniel@iogearbox.net, davem@davemloft.net, hawk@kernel.org, john.fastabend@gmail.com, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, kpsingh@kernel.org, lorenzo.bianconi@redhat.com, netdev@vger.kernel.org, bpf@vger.kernel.org, Jesper Dangaard Brouer , Ilias Apalodimas , Andy Gospodarek , gal@nvidia.com, Saeed Mahameed , tariqt@nvidia.com Subject: Re: [PATCH net-next v2] samples/bpf: fixup some tools to be able to support xdp multibuffer Message-ID: <20230104171733.5fa4638c@kernel.org> In-Reply-To: <87bkne32ly.fsf@toke.dk> References: <20220621175402.35327-1-gospo@broadcom.com> <40fd78fc-2bb1-8eed-0b64-55cb3db71664@gmail.com> <87k0234pd6.fsf@toke.dk> <20230103172153.58f231ba@kernel.org> <87bkne32ly.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 04 Jan 2023 13:28:57 +0100 Toke H=C3=B8iland-J=C3=B8rgensen wrote: > >> Interesting! :) My mental model was closer to GRO by frags=20 > >> so the linear part would have no data, just headers. =20 > > > > That is assumption as well. =20 >=20 > Right, okay, so how many headers? Only Ethernet, or all the way up to > L4 (TCP/UDP)? If we're speaking about guarantees or hard requirements - I think that we can only require / guarantee the Ethernet header. Requiring more will be defeated by tunnels (i.e. adjust_head() + redirect to a veth). > I do seem to recall a discussion around the header/data split for TCP > specifically, but I think I mentally put that down as "something people > may way to do at some point in the future", which is why it hasn't made > it into my own mental model (yet?) :)