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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,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 971A4C4321A for ; Thu, 27 Jun 2019 21:25:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B49720828 for ; Thu, 27 Jun 2019 21:25:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="T36dbXKH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726695AbfF0VZl (ORCPT ); Thu, 27 Jun 2019 17:25:41 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:39922 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726384AbfF0VZl (ORCPT ); Thu, 27 Jun 2019 17:25:41 -0400 Received: by mail-qt1-f193.google.com with SMTP id i34so4108365qta.6 for ; Thu, 27 Jun 2019 14:25:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=ElQV/u013YOYWC11HkhStHYWBt87I6cc9bNTnf9Bdm4=; b=T36dbXKHxrwS69Q8gWHCjPoYPosyIUxHjwSqCIVOfyO4WiE82BX195TJ72d+IEhMjX 26FLfVumUjwSrLC7/ffZG1PiBC2KqW2YSpJPtRbZe132rdMRXDmxSJW9pyJEvZV5M1wQ nCvPyoCxtEH7xXAwwUhUM+3YPoWpZZSU8tjNe4uRm+0+q8WfK3e9HlVE/AwxEXe5y39o iFWiE9nwMPbJ8J8EREMeFlFN/csiLebu41M1Uq4EsMCwV2pFzpPWyegu1brWuuPU75Dl uU41vf4l0tKzEgOyZA/6tXwIZnEWbMzlnyi8Soe3cZeV0A7B8/bLIUT+gvV/87HcYs9Z uqDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=ElQV/u013YOYWC11HkhStHYWBt87I6cc9bNTnf9Bdm4=; b=DGtqs+c/bKAwSM2EGe0dgdKWVgUv0oQkS+cvSoPC8r6uRdmpSDyG2rTMY2P1+Q9efk T1newoko1ZoR+if0SGHPhEv9KUzwNuZ86aMzNmsm96d5SgORBJTghag/4cr4l9LirUyF WIh+es438TEApKZawLOZ9cP66DB4qJ7yAMR7NwZ+jDnifq7e2Z0d5lk0670VtRlApDrd 1A6kEv/J0XubABkE8EXbm5EheODp2wt6s7aQk92k0yWxwNqbl0ydCUfyVVPMbxkdiOBN 6RMQ6YEesz/CN9P0s7y2J8uwYsz5bz2pdvx9aP3Eel7p75gmBbgGANyrCp+eWoDRvTWb Yo+w== X-Gm-Message-State: APjAAAX1XSsKpIXHl1I6h5DZx+PZsxt5UVAiVzTsAoQ7ktWVrAtod85d WvMUvJQ3u8AGcEv67Y0cSPSttg== X-Google-Smtp-Source: APXvYqwS3c8fznhmB0uVN5y7M83pNsjbPuQ5eVwA9n13yNBMIwZrFANycsCBrJoFsUI+f0arYexlmQ== X-Received: by 2002:a0c:880b:: with SMTP id 11mr5066098qvl.185.1561670740197; Thu, 27 Jun 2019 14:25:40 -0700 (PDT) Received: from cakuba.netronome.com ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id v17sm160765qtc.23.2019.06.27.14.25.38 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Thu, 27 Jun 2019 14:25:39 -0700 (PDT) Date: Thu, 27 Jun 2019 14:25:34 -0700 From: Jakub Kicinski To: "Laatz, Kevin" Cc: Jonathan Lemon , netdev@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, bjorn.topel@intel.com, magnus.karlsson@intel.com, bpf@vger.kernel.com, intel-wired-lan@lists.osuosl.org, bruce.richardson@intel.com, ciara.loftus@intel.com Subject: Re: [PATCH 00/11] XDP unaligned chunk placement support Message-ID: <20190627142534.4f4b8995@cakuba.netronome.com> In-Reply-To: References: <20190620083924.1996-1-kevin.laatz@intel.com> Organization: Netronome Systems, Ltd. 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 Thu, 27 Jun 2019 12:14:50 +0100, Laatz, Kevin wrote: > On the application side (xdpsock), we don't have to worry about the user > defined headroom, since it is 0, so we only need to account for the > XDP_PACKET_HEADROOM when computing the original address (in the default > scenario). That assumes specific layout for the data inside the buffer. Some NICs will prepend information like timestamp to the packet, meaning the packet would start at offset XDP_PACKET_HEADROOM + metadata len.. I think that's very limiting. What is the challenge in providing aligned addresses, exactly? From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Kicinski Date: Thu, 27 Jun 2019 14:25:34 -0700 Subject: [Intel-wired-lan] [PATCH 00/11] XDP unaligned chunk placement support In-Reply-To: References: <20190620083924.1996-1-kevin.laatz@intel.com> Message-ID: <20190627142534.4f4b8995@cakuba.netronome.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: On Thu, 27 Jun 2019 12:14:50 +0100, Laatz, Kevin wrote: > On the application side (xdpsock), we don't have to worry about the user > defined headroom, since it is 0, so we only need to account for the > XDP_PACKET_HEADROOM when computing the original address (in the default > scenario). That assumes specific layout for the data inside the buffer. Some NICs will prepend information like timestamp to the packet, meaning the packet would start at offset XDP_PACKET_HEADROOM + metadata len.. I think that's very limiting. What is the challenge in providing aligned addresses, exactly?