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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 1F115C76186 for ; Sat, 27 Jul 2019 20:18:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA0A2208E4 for ; Sat, 27 Jul 2019 20:18:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388335AbfG0USu (ORCPT ); Sat, 27 Jul 2019 16:18:50 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:39698 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387841AbfG0USt (ORCPT ); Sat, 27 Jul 2019 16:18:49 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id E73D11533D862; Sat, 27 Jul 2019 13:18:48 -0700 (PDT) Date: Sat, 27 Jul 2019 13:18:48 -0700 (PDT) Message-Id: <20190727.131848.1034715270924665758.davem@davemloft.net> To: brodie.greenfield@alliedtelesis.co.nz Cc: stephen@networkplumber.org, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, chris.packham@alliedtelesis.co.nz, luuk.paulussen@alliedtelesis.co.nz Subject: Re: [PATCH 0/2] Make ipmr queue length configurable From: David Miller In-Reply-To: <20190725204230.12229-1-brodie.greenfield@alliedtelesis.co.nz> References: <20190725204230.12229-1-brodie.greenfield@alliedtelesis.co.nz> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sat, 27 Jul 2019 13:18:49 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Brodie Greenfield Date: Fri, 26 Jul 2019 08:42:28 +1200 > We want to have some more space in our queue for processing incoming > multicast packets, so we can process more of them without dropping > them prematurely. It is useful to be able to increase this limit on > higher-spec platforms that can handle more items. > > For the particular use case here at Allied Telesis, we have linux > running on our switches and routers, with support for the number of > multicast groups being increased. Basically, this queue length affects > the time taken to fully learn all of the multicast streams. > > Changes in v3: > - Corrected a v4 to v6 typo. As others have voiced, I think it's dangerous to let every netns increase this so readily. We need to either put in a non-initns limit or simply not allow non-init namespaces to change this. But really socket queue limits are a better place to enforce this.