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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 0CD2AC3F2D7 for ; Tue, 3 Mar 2020 20:50:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CBCD120CC7 for ; Tue, 3 Mar 2020 20:50:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583268626; bh=7AE8rMM+e9yVjOf3fq4igUYa/KeCJUzDDBRPZ/WBCec=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=Am9dI0A14QZeeKGZW+y3kU9EEqESvjfVg44CBW4/fHh8nSKUkHXlX/KULBtWEnKX7 K01a/8v3Ai6LnMbmCMs0dequRPha3QxJXk/77V41/0GTIoZzLrqJKfuqNAAyTU4CAe nlohdywHMdbEpAJ9hAxN41ISL0nEx18TXE5trouQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731977AbgCCUuY (ORCPT ); Tue, 3 Mar 2020 15:50:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:42566 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731268AbgCCUuY (ORCPT ); Tue, 3 Mar 2020 15:50:24 -0500 Received: from kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com (unknown [163.114.132.128]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 42AD120848; Tue, 3 Mar 2020 20:50:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583268623; bh=7AE8rMM+e9yVjOf3fq4igUYa/KeCJUzDDBRPZ/WBCec=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=MmneNJNcVy/IcUaO7VxGJMjoNs+Xvjb9W2g+0cY6wC+ui/mhXnyoWyAIhDm4WgQdJ xBYZ1RpvZJ79IRiOu8zFIwaiQ+1SmfVQW0Lb4RUQQXhPNWEWIHoDI6VtQwKp/iYmXm YsMgiI2s+i+HHJ4gpVQUu6VChr6SShnujSS3bxA8= Date: Tue, 3 Mar 2020 12:50:20 -0800 From: Jakub Kicinski To: Daniel Borkmann Cc: Willem de Bruijn , Luigi Rizzo , Network Development , Toke =?UTF-8?B?SMO4aWxhbmQtSsO4cmdlbnNlbg==?= , David Miller , hawk@kernel.org, "Jubran, Samih" , linux-kernel , ast@kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH v4] netdev attribute to control xdpgeneric skb linearization Message-ID: <20200303125020.2baef01b@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <3c27d9c0-eb17-b20f-2d10-01f3bdf8c0d6@iogearbox.net> References: <20200228105435.75298-1-lrizzo@google.com> <20200228110043.2771fddb@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <3c27d9c0-eb17-b20f-2d10-01f3bdf8c0d6@iogearbox.net> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, 3 Mar 2020 20:46:55 +0100 Daniel Borkmann wrote: > Thus, when the data/data_end test fails in generic XDP, the user can > call e.g. bpf_xdp_pull_data(xdp, 64) to make sure we pull in as much as > is needed w/o full linearization and once done the data/data_end can be > repeated to proceed. Native XDP will leave xdp->rxq->skb as NULL, but > later we could perhaps reuse the same bpf_xdp_pull_data() helper for > native with skb-less backing. Thoughts? I'm curious why we consider a xdpgeneric-only addition. Is attaching a cls_bpf program noticeably slower than xdpgeneric?