From owner-freebsd-current@freebsd.org  Fri Nov  6 16:55:50 2015
Return-Path: <owner-freebsd-current@freebsd.org>
Delivered-To: freebsd-current@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 2C399A26049;
 Fri,  6 Nov 2015 16:55:50 +0000 (UTC) (envelope-from hps@selasky.org)
Received: from mail.turbocat.net (heidi.turbocat.net [88.198.202.214])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id DD84B1CDE;
 Fri,  6 Nov 2015 16:55:49 +0000 (UTC) (envelope-from hps@selasky.org)
Received: from laptop015.home.selasky.org (unknown [62.141.129.119])
 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))
 (No client certificate requested)
 by mail.turbocat.net (Postfix) with ESMTPSA id 893BF1FE023;
 Fri,  6 Nov 2015 17:55:46 +0100 (CET)
Subject: Re: Timing issue with Dummynet on high kernel timer interrupt
To: Ian Lepore <ian@freebsd.org>, Luigi Rizzo <rizzo@iet.unipi.it>
References: <6545444AE21C2749939E637E56594CEA3C0DCCC4@gsp-ex02.ds.swin.edu.au>
 <5638B7B5.3030802@selasky.org>
 <6545444AE21C2749939E637E56594CEA3C0DE7FF@gsp-ex02.ds.swin.edu.au>
 <563B2703.5080402@selasky.org>
 <6545444AE21C2749939E637E56594CEA3C0E0BD9@gsp-ex02.ds.swin.edu.au>
 <563C6864.2090907@selasky.org>
 <CA+hQ2+hm2z0MkB-8w5xJM7+iz13r_ZjwmpZBnb30_D_48gaf-w@mail.gmail.com>
 <563C786C.1050305@selasky.org>
 <CA+hQ2+j0WiGgzV119M1ZQiXP5Z7fq7deVxDPkOhvTc7hpTETKw@mail.gmail.com>
 <563CC186.9000807@selasky.org> <563CD533.2000909@selasky.org>
 <1446828229.91534.417.camel@freebsd.org> <563CDA8F.5010901@selasky.org>
Cc: Rasool Al-Saadi <ralsaadi@swin.edu.au>,
 "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>,
 Alexander Motin <mav@FreeBSD.org>,
 FreeBSD Current <freebsd-current@freebsd.org>
From: Hans Petter Selasky <hps@selasky.org>
Message-ID: <563CDBF9.3090800@selasky.org>
Date: Fri, 6 Nov 2015 17:57:29 +0100
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101
 Thunderbird/38.2.0
MIME-Version: 1.0
In-Reply-To: <563CDA8F.5010901@selasky.org>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.20
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
 <freebsd-current.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-current>, 
 <mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current/>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
 <mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 06 Nov 2015 16:55:50 -0000

On 11/06/15 17:51, Hans Petter Selasky wrote:
> On 11/06/15 17:43, Ian Lepore wrote:
>> On Fri, 2015-11-06 at 17:28 +0100, Hans Petter Selasky wrote:
>>> Hi,
>
>>
>> Do the test II results change with this setting?
>>
>>    sysctl kern.timecounter.alloweddeviation=0
>>
>
> Yes, it looks much better:
>
> debug.total: 10013 -> 0
> debug.total: 10013 -> 0
> debug.total: 10012 -> 0
> debug.total: 10012 -> 0
> debug.total: 10012 -> 0
> debug.total: 10013 -> 0
> debug.total: 10012 -> 1
> debug.total: 10013 -> 0
> debug.total: 10013 -> 0
> debug.total: 10013 -> 0
> debug.total: 10012 -> 0
> debug.total: 10013 -> 0
> debug.total: 10013 -> 0
>
> --HPS
>

Thought I still see some unexpected dips, as the test runs for a longer 
amount of time. Not sure what the cause might be.

> debug.total: 10013 -> 0
> debug.total: 10013 -> 0
> debug.total: 10013 -> 0
> debug.total: 9844 -> 0
> debug.total: 10013 -> 0
> debug.total: 10013 -> 0
> debug.total: 10012 -> 0

--HPS