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=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 8FE32C3A59C for ; Thu, 15 Aug 2019 17:11:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 70006205F4 for ; Thu, 15 Aug 2019 17:11:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731322AbfHORLO convert rfc822-to-8bit (ORCPT ); Thu, 15 Aug 2019 13:11:14 -0400 Received: from mail-ed1-f66.google.com ([209.85.208.66]:32834 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731299AbfHORLN (ORCPT ); Thu, 15 Aug 2019 13:11:13 -0400 Received: by mail-ed1-f66.google.com with SMTP id s15so2730889edx.0 for ; Thu, 15 Aug 2019 10:11:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:in-reply-to:references:date :message-id:mime-version:content-transfer-encoding; bh=DG21KkKuGbE22qd7U7CNhzev33PvnhgSnKWOMcxhx0o=; b=M8EoW/er56zqQazD0qUJVXsVD5yZkdlvgiODcueBo39pahWNbOg3sp9yamvVPJQo0u 37qCRNiwtvqApX0bwSpztOUK68upQjlPubmhRYAEdWlgBi7q3eCdoX1s6Sy7aZj3KXVG JfJJyBc0NoQFKpjspZC8k/W4X+x2z90vWK81cidsLXDAHR6zrXUMVDJehpBMBxmsUZbg ztj5kJ4cxMN+ffHgXRhuGwUyWZKVh+AjANS59liz63GKt4lteK4BCLmSNrnxF+nWWwzR m13fusDiXchcNmuHlz8qfWvgfETBwwzU44DIkfQ5gvqtB8uQDDQ+S96PQa0iCThpVcBh 57dQ== X-Gm-Message-State: APjAAAWdTXGBGO0lI5Pir0GzElQ2lH483KojUTvpXpdsDNH+AQV/Fsl+ GkAhZBq/90OWM+wA1KkoBSvQEA== X-Google-Smtp-Source: APXvYqwBCG6PXQ1zbJIvWQF6cb4SXcTTFbXx1veojnlRTDWLgRqtU+ZpZEdGvpBGRpyLhNF7FITOQg== X-Received: by 2002:a17:906:eb8d:: with SMTP id mh13mr5279618ejb.98.1565889072181; Thu, 15 Aug 2019 10:11:12 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([2a00:7660:6da:443::2]) by smtp.gmail.com with ESMTPSA id w14sm652036edf.7.2019.08.15.10.11.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Aug 2019 10:11:11 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 224FB181C2E; Thu, 15 Aug 2019 19:11:11 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: "Samudrala\, Sridhar" , magnus.karlsson@intel.com, bjorn.topel@intel.com, netdev@vger.kernel.org, bpf@vger.kernel.org, intel-wired-lan@lists.osuosl.org, maciej.fijalkowski@intel.com, tom.herbert@intel.com Subject: Re: [PATCH bpf-next 0/5] Add support for SKIP_BPF flag for AF_XDP sockets In-Reply-To: References: <1565840783-8269-1-git-send-email-sridhar.samudrala@intel.com> <87ftm2adi2.fsf@toke.dk> X-Clacks-Overhead: GNU Terry Pratchett Date: Thu, 15 Aug 2019 19:11:11 +0200 Message-ID: <87ftm2wdzk.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org "Samudrala, Sridhar" writes: > On 8/15/2019 4:12 AM, Toke Høiland-Jørgensen wrote: >> Sridhar Samudrala writes: >> >>> This patch series introduces XDP_SKIP_BPF flag that can be specified >>> during the bind() call of an AF_XDP socket to skip calling the BPF >>> program in the receive path and pass the buffer directly to the socket. >>> >>> When a single AF_XDP socket is associated with a queue and a HW >>> filter is used to redirect the packets and the app is interested in >>> receiving all the packets on that queue, we don't need an additional >>> BPF program to do further filtering or lookup/redirect to a socket. >>> >>> Here are some performance numbers collected on >>> - 2 socket 28 core Intel(R) Xeon(R) Platinum 8180 CPU @ 2.50GHz >>> - Intel 40Gb Ethernet NIC (i40e) >>> >>> All tests use 2 cores and the results are in Mpps. >>> >>> turbo on (default) >>> --------------------------------------------- >>> no-skip-bpf skip-bpf >>> --------------------------------------------- >>> rxdrop zerocopy 21.9 38.5 >>> l2fwd zerocopy 17.0 20.5 >>> rxdrop copy 11.1 13.3 >>> l2fwd copy 1.9 2.0 >>> >>> no turbo : echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo >>> --------------------------------------------- >>> no-skip-bpf skip-bpf >>> --------------------------------------------- >>> rxdrop zerocopy 15.4 29.0 >>> l2fwd zerocopy 11.8 18.2 >>> rxdrop copy 8.2 10.5 >>> l2fwd copy 1.7 1.7 >>> --------------------------------------------- >> >> You're getting this performance boost by adding more code in the fast >> path for every XDP program; so what's the performance impact of that for >> cases where we do run an eBPF program? > > The no-skip-bpf results are pretty close to what i see before the > patches are applied. As umem is cached in rx_ring for zerocopy the > overhead is much smaller compared to the copy scenario where i am > currently calling xdp_get_umem_from_qid(). I meant more for other XDP programs; what is the performance impact of XDP_DROP, for instance? >> Also, this is basically a special-casing of a particular deployment >> scenario. Without a way to control RX queue assignment and traffic >> steering, you're basically hard-coding a particular app's takeover of >> the network interface; I'm not sure that is such a good idea... > > Yes. This is mainly targeted for application that create 1 AF_XDP > socket per RX queue and can use a HW filter (via ethtool or TC flower) > to redirect the packets to a queue or a group of queues. Yeah, and I'd prefer it if the handling of this to be unified somehow... -Toke