From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [Patch net-next 4/5] net_sched: forbid setting default qdisc to inappropriate ones Date: Thu, 27 Aug 2015 21:23:59 -0700 (PDT) Message-ID: <20150827.212359.1624170801280596846.davem@davemloft.net> References: <20150827.161850.712938458604844308.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, jhs@mojatatu.com, stephen@networkplumber.org To: xiyou.wangcong@gmail.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:49825 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750837AbbH1EYB (ORCPT ); Fri, 28 Aug 2015 00:24:01 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: Cong Wang Date: Thu, 27 Aug 2015 18:49:09 -0700 > On Thu, Aug 27, 2015 at 4:18 PM, David Miller wrote: >> From: Cong Wang >> Date: Thu, 27 Aug 2015 15:47:55 -0700 >> >>> On Thu, Aug 27, 2015 at 3:42 PM, David Miller wrote: >>>> If you fix it properly, by making every qdisc capable of being ->init()'d >>>> without explicit parameters, it will be the best behavior overall. >>> >>> The problem is ->init() is not even called when setting it as default, >>> since setting a default qdisc doesn't need to create a qdisc. This is >>> why the flag has to be in ops->flags rather than qdisc->flags. >> >> Just sounds like another shortcoming of how default qdiscs are handled, > > It has to, due to its definition. I don't see any other way except we change > the meaning of the default qdisc. We are talking past eachother. If a default qdisc like HTB is choosen, we invoke the ->init() function and we change the HTB ->init() function to do something reasonable if a NULL set of configuration attributes is given. ie. make HTB use some defaults. Please explain to me why this won't fix the problem.