From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: RFC: Nagle latency tuning Date: Tue, 23 Sep 2008 04:23:29 +0200 Message-ID: <20080923022329.GD25711@one.firstfloor.org> References: <20080922232428.GA25711@one.firstfloor.org> <20080922.162158.223213897.davem@davemloft.net> <20080923001409.GB25711@one.firstfloor.org> <20080922.184012.212424947.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: andi@firstfloor.org, csnook@redhat.com, rick.jones2@hp.com, netdev@vger.kernel.org To: David Miller Return-path: Received: from one.firstfloor.org ([213.235.205.2]:41039 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754131AbYIWCSi (ORCPT ); Mon, 22 Sep 2008 22:18:38 -0400 Content-Disposition: inline In-Reply-To: <20080922.184012.212424947.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: > There are many cases where perfectly acceptible heuristics For very low values of "perfect" :) > don't perform optimally, this doesn't mean we disable them > by default. Well they're just broken on a larger and larger fraction of the internet. Router technology more and more often knows something about ports these days and handles flows differently. Assuming they do not is more and more wrong. It's one of these things which looks cool on first look but when you dig deeper is just a bad idea. How should we call a heuristics that is often wrong. A "wrongistic"? :) > > NAT. > > I am more than aware of this, however this doesn't mean it is > sane I agree with you that they're not sane, but they should still be supported. Technically at least they don't violate any standards afaik. Linux should work well even with such setups. In fact it has no other choice because they're so common. "Be liberal what you accept, be conservative what you send". This violates the second principle. > and this kind of setup makes many useful internet services > inaccessible. Sure, in fact that's usually why they were done in the first place, but Linux shouldn't make it unnecessarily worse. Anyways enough said. I guess we have to agree to disagree on this. For completeness I'll still send the patch to set the sysctl by default though just in case you reconsider. -Andi -- ak@linux.intel.com