From owner-freebsd-net@FreeBSD.ORG Mon Jul 4 20:13:43 2005 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C841116A41F; Mon, 4 Jul 2005 20:13:43 +0000 (GMT) (envelope-from chvogt@tm.uka.de) Received: from iramx2.ira.uni-karlsruhe.de (iramx2.ira.uni-karlsruhe.de [141.3.10.81]) by mx1.FreeBSD.org (Postfix) with ESMTP id 875BD43D48; Mon, 4 Jul 2005 20:13:43 +0000 (GMT) (envelope-from chvogt@tm.uka.de) Received: from i72archimedes.tm.uni-karlsruhe.de ([141.3.71.83]) by iramx2.ira.uni-karlsruhe.de with esmtpsa id 1DpXJw-0005Mz-9X; Mon, 04 Jul 2005 22:13:38 +0200 Message-ID: <42C9986F.4000601@tm.uka.de> Date: Mon, 04 Jul 2005 22:13:35 +0200 From: Christian Vogt User-Agent: Mozilla/5.0 (X11; U; Linux i686; de-DE; rv:1.7.6) Gecko/20050317 Thunderbird/1.0.2 Mnenhy/0.7.2.0 X-Accept-Language: de-DE, de, en-us, en MIME-Version: 1.0 To: John-Mark Gurney References: <42C986BB.4020409@tm.uka.de> <20050704191428.GQ727@funkthat.com> In-Reply-To: <20050704191428.GQ727@funkthat.com> X-Enigmail-Version: 0.90.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -15.2 (---------------) X-Spam-Status: No Cc: freebsd-net@freebsd.org, TM-RO2 Subject: Re: tcp_xmit_timer() X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Jul 2005 20:13:43 -0000 Yes, and this (from sys/netinet/tcp_var.h): #define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */ #define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */ ...should say "...for rttvar; 4 bits frac." in both places. - Christian -- Christian Vogt, Institute of Telematics, University of Karlsruhe www.tm.uka.de/~chvogt/pubkey/ John-Mark Gurney wrote: > Christian Vogt wrote this message on Mon, Jul 04, 2005 at 20:58 > +0200: > >> Hi everybody, >> >> just a nit in sys/netinet/tcp_input.c:tcp_xmit_timer(). A comment >> says: >> >> /* * srtt is stored as fixed point with 5 bits after the * binary >> point (i.e., scaled by 8). The following magic * is equivalent to >> the smoothing algorithm in rfc793 with * an alpha of .875 (srtt = >> rtt/8 + srtt*7/8 in fixed * point). Adjust rtt to origin 0. */ >> >> But it should say "...(i.e., scaled by 32)". >> >> Hope this wasn't mentioned before on this list. > > > This isn't the only mismatch: #define TCP_RTT_SHIFT 5 > /* shift for srtt; 3 bits frac. */ > > Maybe wollman can shed light on this? It looks like he just didn't > update the comments in both places... >