From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: tcp congestion policy selection link order fragile Date: Mon, 18 Sep 2006 07:06:00 -0700 (PDT) Message-ID: <20060918.070600.107685035.davem@davemloft.net> References: <20060917122153.GA2932@outpost.ds9a.nl> <20060918.015130.34760190.davem@davemloft.net> <20060918095936.GA6161@outpost.ds9a.nl> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: shemminger@osdl.org, netdev@vger.kernel.org Return-path: Received: from dsl027-180-168.sfo1.dsl.speakeasy.net ([216.27.180.168]:52153 "EHLO sunset.davemloft.net") by vger.kernel.org with ESMTP id S1751668AbWIROGM (ORCPT ); Mon, 18 Sep 2006 10:06:12 -0400 To: bert.hubert@netherlabs.nl In-Reply-To: <20060918095936.GA6161@outpost.ds9a.nl> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: bert hubert Date: Mon, 18 Sep 2006 11:59:36 +0200 > I've tested this patch and it does the job for me, reno is now the default, > even when more advanced options are compiled in, but the rest is still > available. This breaks our intention that when TCP_CONG_ADVANCED is not set, BIC is the default since that is the default congestion control algorithm we want users to get. When TCP_CONG_ADVANCED is disabled, we turn on TCP_CONG_BIC, and your changes cause reno to be the default algorithm in that build case. That's not what we want. Any ordering scheme is wrong or unexpected for _somebody_. Look how easy it was for you to break the BIC default we had in place. To make things sensible for you, your patch causes everyone else got the wrong default. Therefore any ordering scheme is by definition arbitrary and no ordering is better than any other one.