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 A3225C31E40 for ; Thu, 15 Aug 2019 11:12:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7FAE12067D for ; Thu, 15 Aug 2019 11:12:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728128AbfHOLMl (ORCPT ); Thu, 15 Aug 2019 07:12:41 -0400 Received: from mail-ed1-f68.google.com ([209.85.208.68]:40154 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730559AbfHOLMl (ORCPT ); Thu, 15 Aug 2019 07:12:41 -0400 Received: by mail-ed1-f68.google.com with SMTP id h8so1802880edv.7 for ; Thu, 15 Aug 2019 04:12:39 -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; bh=ntIsD69DO/hO6b75AtxLAE4j1t2W0/fwbe66EmMsreM=; b=Cdt4TTpFlIsb19GL2ncJgV+iG9F7iNVQDMMfBbqjMaWU/6yCJ3yq/CO7trF/m+yGjn fA2kAMw1bGv+FBXRx5pBQAsCxQ3WefD40LQ46XZ8zOdMxtvsbNrdAdwiVxKijsdiWgxG 8emLzb37Oqp4FMsewq1NhJkSnWdohaPHNzx3aWzsvWCvotnOyUaY87apNYTHHIK8lM2z VUqoOd4czwdlG4tyvOXecH+7juesmm/nRHOHRL7sN7KfoBzmQUynXQZzkXJV7GgVZS6d eb790dUBltUHgI/NiZMkDRW39T9pkTkuxwF85CHJIJOKrjt+ug2iCEZdWTB0coPHGv1P 521w== X-Gm-Message-State: APjAAAXxkENnKzGwCe2Uxt2yNWLYT2Z0por7jS78dt9b040p/LVPapEy uaLbC4ctmAxZvMQFCDiU/ABHVQ== X-Google-Smtp-Source: APXvYqySmryfwFB28Qyo1faZoMqbuRI9iUKmVaJDkDfpefaX3OWKGu+Vwl+P/M8P9UMOyLYn7wa1rA== X-Received: by 2002:aa7:d755:: with SMTP id a21mr4711292eds.295.1565867559112; Thu, 15 Aug 2019 04:12:39 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk (borgediget.toke.dk. [85.204.121.218]) by smtp.gmail.com with ESMTPSA id c15sm505684edf.37.2019.08.15.04.12.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Aug 2019 04:12:38 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 00332181C2E; Thu, 15 Aug 2019 13:12:37 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Sridhar Samudrala , magnus.karlsson@intel.com, bjorn.topel@intel.com, netdev@vger.kernel.org, bpf@vger.kernel.org, sridhar.samudrala@intel.com, 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: <1565840783-8269-1-git-send-email-sridhar.samudrala@intel.com> References: <1565840783-8269-1-git-send-email-sridhar.samudrala@intel.com> X-Clacks-Overhead: GNU Terry Pratchett Date: Thu, 15 Aug 2019 13:12:37 +0200 Message-ID: <87ftm2adi2.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org 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? 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... -Toke