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=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 B1655C433B4 for ; Sun, 18 Apr 2021 16:18:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B374610EA for ; Sun, 18 Apr 2021 16:18:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232052AbhDRQSv (ORCPT ); Sun, 18 Apr 2021 12:18:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:58549 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231368AbhDRQSt (ORCPT ); Sun, 18 Apr 2021 12:18:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618762699; 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=gtqF7+8hdOsOAqsZblGuMHHe5YxbPyqEJw9acCV3MPw=; b=V7z/HAw/PwPtEOIkFYmwh2aKhBNuknk8An3HAoTA3tErvLcBETqC9Hq6GGfdREu5B+aS6+ uw4CbdFD5zh+rZYzlZHUPTCeVibTUjvbzJBgbrchdbJm/9YdZ+U0tDNHcHfFNVLZC4NBL4 h9WYBWUJ8A2dJVoQRyQ8tWBN18CENaw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-394-lYJvDT76NgKpzdeP30YW3g-1; Sun, 18 Apr 2021 12:18:15 -0400 X-MC-Unique: lYJvDT76NgKpzdeP30YW3g-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D4231817469; Sun, 18 Apr 2021 16:18:13 +0000 (UTC) Received: from carbon (unknown [10.36.110.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id 59DD1107D5C6; Sun, 18 Apr 2021 16:18:02 +0000 (UTC) Date: Sun, 18 Apr 2021 18:18:01 +0200 From: Jesper Dangaard Brouer To: Magnus Karlsson Cc: Lorenzo Bianconi , bpf , Network Development , lorenzo.bianconi@redhat.com, "David S. Miller" , Jakub Kicinski , Alexei Starovoitov , Daniel Borkmann , shayagr@amazon.com, sameehj@amazon.com, John Fastabend , David Ahern , Eelco Chaudron , Jason Wang , Alexander Duyck , Saeed Mahameed , "Fijalkowski, Maciej" , Tirthendu , brouer@redhat.com Subject: Re: [PATCH v8 bpf-next 00/14] mvneta: introduce XDP multi-buffer support Message-ID: <20210418181801.17166935@carbon> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, 16 Apr 2021 16:27:18 +0200 Magnus Karlsson wrote: > On Thu, Apr 8, 2021 at 2:51 PM Lorenzo Bianconi wrote: > > > > This series introduce XDP multi-buffer support. The mvneta driver is > > the first to support these new "non-linear" xdp_{buff,frame}. Reviewers > > please focus on how these new types of xdp_{buff,frame} packets > > traverse the different layers and the layout design. It is on purpose > > that BPF-helpers are kept simple, as we don't want to expose the > > internal layout to allow later changes. > > > > For now, to keep the design simple and to maintain performance, the XDP > > BPF-prog (still) only have access to the first-buffer. It is left for > > later (another patchset) to add payload access across multiple buffers. > > This patchset should still allow for these future extensions. The goal > > is to lift the XDP MTU restriction that comes with XDP, but maintain > > same performance as before. [...] > > > > [0] https://netdevconf.info/0x14/session.html?talk-the-path-to-tcp-4k-mtu-and-rx-zerocopy > > [1] https://github.com/xdp-project/xdp-project/blob/master/areas/core/xdp-multi-buffer01-design.org > > [2] https://netdevconf.info/0x14/session.html?tutorial-add-XDP-support-to-a-NIC-driver (XDPmulti-buffers section) > > Took your patches for a test run with the AF_XDP sample xdpsock on an > i40e card and the throughput degradation is between 2 to 6% depending > on the setup and microbenchmark within xdpsock that is executed. And > this is without sending any multi frame packets. Just single frame > ones. Tirtha made changes to the i40e driver to support this new > interface so that is being included in the measurements. Could you please share Tirtha's i40e support patch with me? I would like to reproduce these results in my testlab, in-order to figure out where the throughput degradation comes from. > What performance do you see with the mvneta card? How much are we > willing to pay for this feature when it is not being used or can we in > some way selectively turn it on only when needed? Well, as Daniel says performance wise we require close to /zero/ additional overhead, especially as you state this happens when sending a single frame, which is a base case that we must not slowdown. -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer