From owner-freebsd-threads@FreeBSD.ORG  Tue Jul  4 23:24:42 2006
Return-Path: <owner-freebsd-threads@FreeBSD.ORG>
X-Original-To: freebsd-threads@freebsd.org
Delivered-To: freebsd-threads@freebsd.org
Received: from localhost.my.domain (localhost [127.0.0.1])
	by hub.freebsd.org (Postfix) with ESMTP id 22DED16A4DD;
	Tue,  4 Jul 2006 23:24:42 +0000 (UTC)
	(envelope-from davidxu@freebsd.org)
From: David Xu <davidxu@freebsd.org>
To: Julian Elischer <julian@elischer.org>
Date: Wed, 5 Jul 2006 07:24:18 +0800
User-Agent: KMail/1.8.2
References: <20060703101554.Q26325@fledge.watson.org>
	<44AAC47F.2040508@elischer.org>
	<200607050706.33502.davidxu@freebsd.org>
In-Reply-To: <200607050706.33502.davidxu@freebsd.org>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200607050724.18740.davidxu@freebsd.org>
Cc: Daniel Eischen <deischen@freebsd.org>, Robert Watson <rwatson@freebsd.org>,
	freebsd-threads@freebsd.org
Subject: Re: Strawman proposal: making libthr default thread implementation?
X-BeenThere: freebsd-threads@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Threading on FreeBSD <freebsd-threads.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-threads>, 
	<mailto:freebsd-threads-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-threads>
List-Post: <mailto:freebsd-threads@freebsd.org>
List-Help: <mailto:freebsd-threads-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-threads>,
	<mailto:freebsd-threads-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 04 Jul 2006 23:24:42 -0000

On Wednesday 05 July 2006 07:06, David Xu wrote:

> Cann't solaris's user usage scheduler will solve the problem ? if I
> recall it correctly, the decay factor in 4bsd scheduler can be changed
> dynamically for a thread, the decay factor can be stored in thread
> structure, and timeslice can be dynamically changed, also can be in thread
> structure, unlike current implementation, timeslice is fixed,  this may
> make fair scheduling  possible without ksegrp.
>
> Also will the roundrobin callout preempt a thread ?  if that's true, then
> when every timeslice tick, a thread exhausted its timeslice is put at head
> of runqueue, isn't it a bug ? the callout is somewhat random for a thread,
> might not be a problem...

OK, I just digged out the paper in my disks,  here is the reference:
http://people.freebsd.org/~davidxu/doc/solaris2.pdf

[the address thread@freebsd.org is removed]

I think we really should do more work in kernel scheduler, and remove
ksegrp.

David Xu