From owner-freebsd-stable@FreeBSD.ORG Tue Jun 12 09:11:54 2012 Return-Path: Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id D1451106566B for ; Tue, 12 Jun 2012 09:11:54 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (lurza.secnetix.de [IPv6:2a01:170:102f::2]) by mx1.freebsd.org (Postfix) with ESMTP id E31F68FC17 for ; Tue, 12 Jun 2012 09:11:53 +0000 (UTC) Received: from lurza.secnetix.de (localhost [127.0.0.1]) by lurza.secnetix.de (8.14.3/8.14.3) with ESMTP id q5C9BaOZ097970; Tue, 12 Jun 2012 11:11:52 +0200 (CEST) (envelope-from oliver.fromme@secnetix.de) Received: (from olli@localhost) by lurza.secnetix.de (8.14.3/8.14.3/Submit) id q5C9BaGj097969; Tue, 12 Jun 2012 11:11:36 +0200 (CEST) (envelope-from olli) Date: Tue, 12 Jun 2012 11:11:36 +0200 (CEST) Message-Id: <201206120911.q5C9BaGj097969@lurza.secnetix.de> From: Oliver Fromme To: freebsd-stable@FreeBSD.ORG, momchil@xaxo.eu In-Reply-To: <86sje17jnx.wl%momchil@xaxo.eu> X-Newsgroups: list.freebsd-stable User-Agent: tin/1.9.6-20101126 ("Burnside") (UNIX) (FreeBSD/6.4-PRERELEASE-20080904 (i386)) MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.3.9 (lurza.secnetix.de [127.0.0.1]); Tue, 12 Jun 2012 11:11:52 +0200 (CEST) Cc: Subject: Re: ULE Scheduler X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: freebsd-stable@FreeBSD.ORG, momchil@xaxo.eu List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Jun 2012 09:11:54 -0000 ?????? ?????? wrote: > I compiled the same kernel with the 4BSD scheduler today and it seems > that the processes jump accross cores too. What exactly is the problem that you're seeing? Do you have performance problems? If so, then they're probably *not* caused by processes "jumping across cores". Have you read Daniel Kalchev's reply in this thread? He explained very well why that's not a problem usually. Also note that top(1) only shows one snapshot every second or two. It does not show you the hundreds (or thousands) of thread switches that happen every second. In fact, top(1) shows a very misleading picture because it creates the wrong impression that your CPU-bound processes are almost the only ones being scheduled on your cores. Most of the time, people looking at top(1) see problems that don't exist. Another example is the amount of "free" memory displayed by top that is often misinterpreted. I suggest you just keep the standard scheduler (i.e. ULE). If you don't have a performance problem (i.e. a problem that you can measure by other means than top), then don't try to fix it. Chances are you make things worse. Best regards Oliver -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün- chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd "The scanf() function is a large and complex beast that often does something almost but not quite entirely unlike what you desired." -- Chris Torek