From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH] codel: refine one condition to avoid a nul rec_inv_sqrt Date: Fri, 10 Aug 2012 17:16:11 +0200 Message-ID: <1344611771.31104.2716.camel@edumazet-glaptop> References: <1343631141.2626.13293.camel@edumazet-glaptop> <20120730.145412.1689803770003231369.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, lp2s1h@gmail.com To: David Miller Return-path: Received: from mail-bk0-f46.google.com ([209.85.214.46]:46116 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754572Ab2HJPQQ (ORCPT ); Fri, 10 Aug 2012 11:16:16 -0400 Received: by bkwj10 with SMTP id j10so639098bkw.19 for ; Fri, 10 Aug 2012 08:16:15 -0700 (PDT) In-Reply-To: <20120730.145412.1689803770003231369.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 2012-07-30 at 14:54 -0700, David Miller wrote: > From: Eric Dumazet > Date: Mon, 30 Jul 2012 08:52:21 +0200 > > > From: Eric Dumazet > > > > One condition before codel_Newton_step() was not good if > > we never left the dropping state for a flow. As a result > > rec_inv_sqrt was 0, instead of the ~0 initial value. > > > > codel control law was then set to a very aggressive mode, dropping > > many packets before reaching 'target' and recovering from this problem. > > > > To keep codel_vars_init() as efficient as possible, refine > > the condition to make sure rec_inv_sqrt initial value is correct > > > > Many thanks to Anton Mich for discovering the issue and suggesting > > a fix. > > > > Reported-by: Anton Mich > > Signed-off-by: Eric Dumazet > > Applied and queued up for -stable. Hi David, I think this patch got lost somehow ? Thanks