From owner-freebsd-questions@FreeBSD.ORG Thu Dec 29 15:48:18 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DC87816A41F for ; Thu, 29 Dec 2005 15:48:18 +0000 (GMT) (envelope-from cracauer@schlepper.zs64.net) Received: from schlepper.zs64.net (schlepper.zs64.net [212.12.50.230]) by mx1.FreeBSD.org (Postfix) with ESMTP id 16D4B43D5C for ; Thu, 29 Dec 2005 15:48:17 +0000 (GMT) (envelope-from cracauer@schlepper.zs64.net) Received: from schlepper.zs64.net (schlepper [212.12.50.230]) by schlepper.zs64.net (8.13.3/8.12.9) with ESMTP id jBTFmHYT000705; Thu, 29 Dec 2005 16:48:17 +0100 (CET) (envelope-from cracauer@schlepper.zs64.net) Received: (from cracauer@localhost) by schlepper.zs64.net (8.13.3/8.12.9/Submit) id jBTFmGCn000704; Thu, 29 Dec 2005 10:48:16 -0500 (EST) (envelope-from cracauer) Date: Thu, 29 Dec 2005 10:48:16 -0500 From: Martin Cracauer To: Kiffin Gish Message-ID: <20051229104816.B581@cons.org> References: <1135855260.1034.5.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <1135855260.1034.5.camel@localhost>; from kiffin.gish@planet.nl on Thu, Dec 29, 2005 at 12:21:00PM +0100 Cc: freebsd-questions@freebsd.org Subject: Re: Using SCHED_ULE vs. SCHED_4BSD ... X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Dec 2005 15:48:19 -0000 Kiffin Gish wrote on Thu, Dec 29, 2005 at 12:21:00PM +0100: > I recently upgraded from 5.4 to 6.0 and noticed the introduction of > option SCHED_ULE for supporting multi-processor environments. > > However, I understood that using SCHED_ULE with only one CPU can also > improve performance significantly. > > Is this true, and if so, what are the risks involved dropping good old > SCHED_4BSD for the new-and-improved scheduler? I have not even noticed an increase in performance from ULE when running my benchmark suite on a two-processor system. Some people say ULE has problems, but mostly on high CPU counts. So it probably doesn't matter either way. Martin -- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Martin Cracauer http://www.cons.org/cracauer/ FreeBSD - where you want to go, today. http://www.freebsd.org/