From owner-freebsd-stable@FreeBSD.ORG Sun Jan 20 19:17:33 2008 Return-Path: Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BA17616A417 for ; Sun, 20 Jan 2008 19:17:33 +0000 (UTC) (envelope-from stephen@math.missouri.edu) Received: from cauchy.math.missouri.edu (cauchy.math.missouri.edu [128.206.184.213]) by mx1.freebsd.org (Postfix) with ESMTP id 93A8313C46B for ; Sun, 20 Jan 2008 19:17:33 +0000 (UTC) (envelope-from stephen@math.missouri.edu) Received: from laptop2.gateway.2wire.net (cauchy.math.missouri.edu [128.206.184.213]) by cauchy.math.missouri.edu (8.14.2/8.14.1) with ESMTP id m0KJGX7M023104; Sun, 20 Jan 2008 13:16:34 -0600 (CST) (envelope-from stephen@math.missouri.edu) Message-ID: <47939E4B.5050706@math.missouri.edu> Date: Sun, 20 Jan 2008 13:17:31 -0600 From: Stephen Montgomery-Smith User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.1.11) Gecko/20080109 SeaMonkey/1.1.7 MIME-Version: 1.0 To: Jeremy Chadwick References: <479388C0.50507@highperformance.net> <47938F21.6020308@math.missouri.edu> <20080120191316.GA13382@eos.sc1.parodius.com> In-Reply-To: <20080120191316.GA13382@eos.sc1.parodius.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-stable , "Jason C. Wells" , TooMany Secrets Subject: Re: Scheduler in Various Docs X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 20 Jan 2008 19:17:33 -0000 Jeremy Chadwick wrote: > On Sun, Jan 20, 2008 at 07:40:07PM +0100, TooMany Secrets wrote: >> On 1/20/08, Stephen Montgomery-Smith wrote: >>> Jason C. Wells wrote: >>>> The comments regarding SCHED_ULE and SCHED_4BSD are inconsistent with >>>> information found in the email archives. LINT says ULE is experimental. >>>> The handbook doesn't mention ULE at all. The archives say ULE is the >>>> new recommended scheduler. >>>> >>>> If ULE is in fact the current recommendation, then a few docs need to be >>>> updated. >>> To add to Jason's point - why does GENERIC still default to SCHED_4BSD? >>> Are there plans to change this before 7.0 is truly released? >> Excuse me for my bad english... >> >> This question was mentioned two or three months ago. The answer was >> that in 7.1, after the ULE will be tested in 7.0, it will be the >> defacto scheduler in FreeBSD. First, the scheduler need the best >> benchark in the world; a few thousand users testing in real-life >> situations on a daily basis. > > This is correct. There was a very large discussion on freebsd-current > (which would've been discussing 7.x at that point) about what scheduler > should be the default for RELENG_7 (4BSD or the "new" ULE (a.k.a. > SMP2)). It was ""voted"" (note the quotes) that SCHED_4BSD should > remain the default until 7.1 was released, since if there turned out > to be a gigantic bug in the new scheduler, we wouldn't want people to > get bit by it (thus harming the stability reputation of -RELEASE and > -STABLE). The 4BSD scheduler is still considered stable and has a > track record to prove it. > > In a way, SCHED_ULE on 7.x is still considered "experimental" in the > sense that it needs lots of people testing it. So far all the results > have been positive (unlike SCHED_ULE on 6.x and 5.x, which were very > broken -- hence the rewrite!). > > If the OP wants to read the thread/discussion (it's long), I can dig up > a URL to it in the archives. Thanks. You both answered my question admirably.