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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 CD5F2C6778F for ; Wed, 25 Jul 2018 18:13:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8947420844 for ; Wed, 25 Jul 2018 18:13:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="g3JHWrCW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8947420844 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730555AbeGYT0W (ORCPT ); Wed, 25 Jul 2018 15:26:22 -0400 Received: from mail-io0-f195.google.com ([209.85.223.195]:35639 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729514AbeGYT0W (ORCPT ); Wed, 25 Jul 2018 15:26:22 -0400 Received: by mail-io0-f195.google.com with SMTP id w11-v6so7106304iob.2; Wed, 25 Jul 2018 11:13:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=VW582KrGB6yEvf/lwW6bEIySdRkbggnQEBsDyIVGqSM=; b=g3JHWrCWNY1XucoVHS5kzq+dycNQ+47jxBPcWDpmMlduPgjlIqjRwPqewgRum+3owU sMXDSRkKa7sZN96XJTiX/5ww7m0GmjGC9Os8wU9s4LQKQEdGn6Lz7IXGqjj1f9acnM2b otNZBf0zZBz77Uu2cN5L/+H3XATgD4WjNUPUwCOsHQe2O9Sr+CDi2Z6A9f5uUgflx7Y7 LEvUzcy2k3xhqPPXhAHgiWs0RqefZBSmNgkVweL8Wv0V88vVEtPyRTldY4l836HLMpiR dHw+J3DxonZjmjXSEP2d8+0FGJNGrRwjIaANQBBayQbXJcWRKzY1dbFrKQKt9dA0yiWn cKjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=VW582KrGB6yEvf/lwW6bEIySdRkbggnQEBsDyIVGqSM=; b=eZQbn8PpiD0ZsNF8UOZbXhtsZxWLx7ZG/dUxEMbNk3W/WFlI3gCBtuHssbUtA1eKY2 Wq8CTFsrUcJOzZdQ7mh6SR2ndeCwVGp9x/qHAJ+U/SkS8w7cvV03bIB7WmeGQchoR+pv fYUntCXeYXlvN4kcTY7j+3vqDbi5gDtcwK6euvtis8Q1W4nmOfDZ9uZUHGZnoBSLD/bA mJNWocvetKg63GKQkJs6qa5HfDM2twcjWS918gLSmaTM9CsKc4Z5bFeOxnTMbMJoxwnI BA5KgWvjwOIfjrKU3psvvSDVWKZ8tQm/TQiIiUUg7oqgv/hEK5zhBd8z2oKULtaxgDm4 b1zQ== X-Gm-Message-State: AOUpUlFPpPOFSO2po5Quh37JCMMuA2e5bQ0o28il2LfQlsk0owuvT1D4 aQvkUHYcMacRo9+KQTUVBesUectC X-Google-Smtp-Source: AAOMgpenBt+KXFH6Y7qzVcgNSINHFljDuoKZNa8CZIwPvy629qkFY4jIloWpFzxkk3ifRcxLWUYQiQ== X-Received: by 2002:a6b:9e91:: with SMTP id h139-v6mr17754978ioe.185.1532542412828; Wed, 25 Jul 2018 11:13:32 -0700 (PDT) Received: from dsa-mb.local ([2601:282:800:fd80:e4d8:8895:822a:720a]) by smtp.googlemail.com with ESMTPSA id g26-v6sm137929iti.0.2018.07.25.11.13.30 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Jul 2018 11:13:31 -0700 (PDT) Subject: Re: [PATCH RFC/RFT net-next 00/17] net: Convert neighbor tables to per-namespace To: "Eric W. Biederman" Cc: Cong Wang , David Miller , Linux Kernel Network Developers , nikita.leshchenko@oracle.com, Roopa Prabhu , Stephen Hemminger , Ido Schimmel , Jiri Pirko , Saeed Mahameed , Alexander Aring , linux-wpan@vger.kernel.org, NetFilter , LKML References: <1a3f59a9-0ba5-c83f-16a6-f9550a84f693@gmail.com> <1a27e301-3275-b349-a2f8-afdfdc02f04f@gmail.com> <20180718.125938.2271502580775162784.davem@davemloft.net> <28c30574-391c-b4bd-c337-51d3040d901a@gmail.com> <5021d874-8e99-6eba-f24b-4257c62d4457@gmail.com> <87muufze8w.fsf@xmission.com> <4b03b5f6-87ce-9ff2-7c14-598beebd8fb8@gmail.com> <87zhyfw70m.fsf@xmission.com> From: David Ahern Message-ID: Date: Wed, 25 Jul 2018 12:13:30 -0600 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <87zhyfw70m.fsf@xmission.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/25/18 11:38 AM, Eric W. Biederman wrote: > > Absolutely NOT. Global thresholds are exactly correct given the fact > you are running on a single kernel. > > Memory is not free (Even though we are swimming in enough of it memory > rarely matters). One of the few remaining challenges is for containers > is finding was to limit resources in such a way that one application > does not mess things up for another container during ordinary usage. > > It looks like the neighbour tables absolutely are that kind of problem, > because the artificial limits are too strict. Completely giving up on > limits does not seem right approach either. We need to fix the limits > we have (perhaps making them go away entirely), not just apply a > band-aid. Let's get to the bottom of this and make the system better. Eric: yes, they all share the global resource of memory and there should be limits on how many entries a remote entity can create. Network namespaces can provide a separation such that one namespace does not disrupt networking in another. It is absolutely appropriate to do so. Your rigid stance is inconsistent given the basic meaning of a network namespace and the parallels to this same problem -- bridges, vxlans, and ip fragments. Only neighbor tables are not per-device or per namespace; your insistence on global limits is missing the mark and wrong.