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 097D0CA9ECB for ; Fri, 1 Nov 2019 00:22:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDFAA2083E for ; Fri, 1 Nov 2019 00:22:00 +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="itp86Bjs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727754AbfKAAWA (ORCPT ); Thu, 31 Oct 2019 20:22:00 -0400 Received: from mail-lf1-f66.google.com ([209.85.167.66]:34537 "EHLO mail-lf1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727133AbfKAAWA (ORCPT ); Thu, 31 Oct 2019 20:22:00 -0400 Received: by mail-lf1-f66.google.com with SMTP id f5so6054338lfp.1 for ; Thu, 31 Oct 2019 17:21:58 -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=EV2fbUKu73gEX5+CIj3b5YkYQITcbwccDU3gSlwZNAU=; b=itp86BjsasKlqgiwsIms8Ib6Hdl0ma48ViJ4vhEXxoXhlR6DRi1aTylRXntCcq9Ws4 8soRV0LTFl27mtSTVh1OYImgL1OR0o6hh+wqfTKN6K/wnltUPIHuRvLnWggtt1es++sO sQbWaBtzpGw6lfZ+wTdmIICENwt86tFCLpvVW5g7tjFbmpRSqa+gmhMWbfD8lHqVvGtw fXanExQxG6sW7ICqVeakTqeT8w7jJIPxBIxKPdnbOBHPSRKkqG+Cm8m7R3HI3mG1AKno /WgPaSnGskagXLeWHhVFZSBFk0rIAFurvKXMDoDsEW0aV9epr/fBqJwH4sqcr/NfPgPl FCHA== 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=EV2fbUKu73gEX5+CIj3b5YkYQITcbwccDU3gSlwZNAU=; b=iri+rkmKg+Ua7IEPWD2SdG9LduNouefSEqe4yos/ofvetLyi19XLsQ1ifRP2E2ljAu EbKOlfbMS8JRa9i7k/6mARrX7hGyEldHncdVfowSO9DKT/OasanbE0jsiAMBT5zLTgcc K5iV5Oe6XRhQ3JjwKQw1Y5JdBt4ebLHjWfa6J7z6g1jHqgRxNcBx8dgZkUidos1FIZfE L3xhAtl1v1AMoJws/Bhhub9v1Pub7SnX3MCDV37XLA30FtN4ESLcWn9bO3RFYx48FjvF VoGePqi0V5MnXUODmsx4l0MsWh1DYWwEVXDXPw/404DTsQ2bs0U2HK0iFrM4WkDsUjVu QarQ== X-Gm-Message-State: APjAAAXYwuNHo8PpRhUFhAwQkjtw79qSbb/3hDPqWiyuAuD5nRHQiOHU SzyE6RyoxMgaaxXJxQTc71gHeg== X-Google-Smtp-Source: APXvYqwdOpLsUGthqHH2HozLFklWyWYEyoWpdzJcVOkKt3ba3wg8Z1Oo9UPDW0MZ+NNaTICdOe91/g== X-Received: by 2002:ac2:5109:: with SMTP id q9mr5383215lfb.145.1572567717894; Thu, 31 Oct 2019 17:21:57 -0700 (PDT) Received: from cakuba.netronome.com ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id 141sm1899971ljj.37.2019.10.31.17.21.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Oct 2019 17:21:57 -0700 (PDT) Date: Thu, 31 Oct 2019 17:21:48 -0700 From: Jakub Kicinski To: "Samudrala, Sridhar" Cc: bjorn.topel@gmail.com, alexei.starovoitov@gmail.com, bjorn.topel@intel.com, bpf@vger.kernel.org, intel-wired-lan@lists.osuosl.org, maciej.fijalkowski@intel.com, magnus.karlsson@intel.com, netdev@vger.kernel.org, toke@redhat.com, tom.herbert@intel.com, David Miller Subject: Re: [Intel-wired-lan] FW: [PATCH bpf-next 2/4] xsk: allow AF_XDP sockets to receive packets directly from a queue Message-ID: <20191031172148.0290b11f@cakuba.netronome.com> In-Reply-To: <2e27b8d9-4615-cd8d-93de-2adb75d8effa@intel.com> References: <2e27b8d9-4615-cd8d-93de-2adb75d8effa@intel.com> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Thu, 31 Oct 2019 15:38:42 -0700, Samudrala, Sridhar wrote: > Do you think it will be possible to avoid this overhead when mitigations are turned ON? > The other part of the overhead is going through the redirect path. Yes, you should help Maciej with the XDP bulking. > Can i assume that your silence as an indication that you are now okay with optional bypass > flag as long as it doesn't effect the normal XDP datapath. If so, i will respin and submit > the patches against the latest bpf-next This logic baffles me. I absolutely hate when people repost patches after I nack them without even as much as mentioning my objections in the cover letter. My concern was that we want the applications to encode fast path logic in BPF and load that into the kernel. So your patch works fundamentally against that goal: I worry that with the volume of patches that get posted each day objections of a measly contributor like myself will get forgotten if I don't reply to each posting, yet replying each time makes me look bullish or whatnot (apart from being an utter waste of time). Ugh.