From owner-freebsd-stable@FreeBSD.ORG  Fri Jan 23 10:15:50 2009
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
Delivered-To: stable@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 11A76106564A;
	Fri, 23 Jan 2009 10:15:50 +0000 (UTC)
	(envelope-from luigi@onelab2.iet.unipi.it)
Received: from onelab2.iet.unipi.it (onelab2.iet.unipi.it [131.114.9.129])
	by mx1.freebsd.org (Postfix) with ESMTP id C69B58FC16;
	Fri, 23 Jan 2009 10:15:49 +0000 (UTC)
	(envelope-from luigi@onelab2.iet.unipi.it)
Received: by onelab2.iet.unipi.it (Postfix, from userid 275)
	id 3FF6373098; Fri, 23 Jan 2009 11:21:14 +0100 (CET)
Date: Fri, 23 Jan 2009 11:21:14 +0100
From: Luigi Rizzo <rizzo@iet.unipi.it>
To: Oleg Bulyzhin <oleg@FreeBSD.org>
Message-ID: <20090123102114.GA42867@onelab2.iet.unipi.it>
References: <20090123081028.GA38763@onelab2.iet.unipi.it>
	<20090123085337.GB54838@lath.rinet.ru>
	<20090123092312.GC40642@onelab2.iet.unipi.it>
	<20090123094420.GC54838@lath.rinet.ru>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20090123094420.GC54838@lath.rinet.ru>
User-Agent: Mutt/1.4.2.3i
Cc: stable@FreeBSD.org, re@FreeBSD.org
Subject: Re: backporting dummynet's q_time change ? (svn 184414)
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 23 Jan 2009 10:15:50 -0000

On Fri, Jan 23, 2009 at 12:44:20PM +0300, Oleg Bulyzhin wrote:
> On Fri, Jan 23, 2009 at 10:23:12AM +0100, Luigi Rizzo wrote:
> 
> > this is also in RELENG_7 but i am not sure whether this workaround
> > has any drawback e.g., when curr_time passes a 32-bit boundary
> > there seems to be an incorrect setting of q->numbytes
> 
> Workaround is fine in average. It may fail for:
> 1) _very_ idle flow (more than 2^32 ticks) while calculating q->avg
> 2) any flow once per 2^32 ticks
> then q_time will be updated and things will be ok again.

understand - my question is whether there is strong objection
in applying the real fix (the one in HEAD) rather than this
workaround.
In my opinion the MFC is quite safe as I explained.

cheers
luigi