From owner-freebsd-arch@FreeBSD.ORG Wed Sep 29 20:11:02 2004 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7F85A16A4CE for ; Wed, 29 Sep 2004 20:11:02 +0000 (GMT) Received: from mail1.speakeasy.net (mail1.speakeasy.net [216.254.0.201]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4C78B43D48 for ; Wed, 29 Sep 2004 20:11:02 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 28384 invoked from network); 29 Sep 2004 20:11:02 -0000 Received: from dsl027-160-063.atl1.dsl.speakeasy.net (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) encrypted SMTP for ; 29 Sep 2004 20:10:59 -0000 Received: from [10.50.40.210] (gw1.twc.weather.com [216.133.140.1]) (authenticated bits=0) by server.baldwin.cx (8.12.11/8.12.11) with ESMTP id i8TKAukO012092; Wed, 29 Sep 2004 16:10:56 -0400 (EDT) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: freebsd-arch@FreeBSD.org Date: Wed, 29 Sep 2004 10:55:47 -0400 User-Agent: KMail/1.6.2 References: <1096133353.53798.17613.camel@palm.tree.com> <200409281056.00870.jhb@FreeBSD.org> <1096468734.3733.1177.camel@palm.tree.com> In-Reply-To: <1096468734.3733.1177.camel@palm.tree.com> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200409291055.48387.jhb@FreeBSD.org> X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on server.baldwin.cx cc: "freebsd-arch@freebsd.org" cc: Julian Elischer cc: Stephan Uphoff Subject: Re: sched_userret priority adjustment patch for sched_4bsd X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Sep 2004 20:11:02 -0000 On Wednesday 29 September 2004 10:38 am, Stephan Uphoff wrote: > On Tue, 2004-09-28 at 10:56, John Baldwin wrote: > > If A has a priority boost from tsleep() this is intentional, however. > > The priroity boosts from tsleep() are _supposed_ to do this so as to > > favor interactive tasks. Note that if you add the code to always raise > > td_priority while in the kernel as below you may end up defeating this > > well-known feature of the 4BSD scheduler. > > OK - you and Julian convinced me that this is a feature that I should > have known about. Without test cases or interactivity benchmarks > discussions if this is still a desirable feature are probably useless. > I will revisit the this once test cases materialize or I have time to > think about a benchmark (Not likely anytime soon). That's ok. This discussion has been very fruitful on my end at least as talking this out has helped me get a much better grasp on how this stuff works on 4.x and should be done in 5.x to obtain at least somewhat similar behavior. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org