From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756773AbXJNKjT (ORCPT ); Sun, 14 Oct 2007 06:39:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755349AbXJNKjF (ORCPT ); Sun, 14 Oct 2007 06:39:05 -0400 Received: from [212.12.190.105] ([212.12.190.105]:38273 "EHLO raad.intranet" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1755367AbXJNKjC convert rfc822-to-8bit (ORCPT ); Sun, 14 Oct 2007 06:39:02 -0400 From: Al Boldi To: linux-kernel@vger.kernel.org Subject: Re: [2.6.20.21 review 12/35] TCP: Fix TCP handling of SACK in Date: Sun, 14 Oct 2007 13:38:51 +0300 User-Agent: KMail/1.5 Cc: netdev@vger.kernel.org MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Message-Id: <200710141338.51927.a1426z@gawab.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ilpo Järvinen wrote: > Willy Tarreau wrote: > > I agree with this. The impression I got from the description of the two > > patches I merged was that the problems they fix were quite annoying. But > > maybe I should take that with a grain of salt. > > No, it's not a grain of salt. I would say its utterly broken, out loud. > But many people are not that much into time-seq graphs (that I'm familiar > with), they are pleased when it seems to work well enough even though > from my perspective, it is simply unacceptable in worst cases (not > speaking of theoretical ones here, have seen very bad performance). Not > that it always is that bad, depends on phase of the opposite direction > what happens. > > Somebody asked me when those four patches were made about this, I put > these there back then: > > http://www.cs.helsinki.fi/u/ijjarvin/bidir-showcase/ > > They are generated from my old test archives and thus may have a bit > differences in TCP variant, which may slightly differ from mainline > here and there (my point was just to show how it breaks). Typical > people wouldn't even notice those minor differences compared with the > bidir brokeness which is very visible in all except in the fixed "ok" > case. Please judge for yourself whether I overexaggrated or not... :-) It would probably be helpful, if you could post a specific testcase and a combo-patch of your fixes. Thanks! -- Al