From owner-freebsd-current@FreeBSD.ORG Thu Feb 12 23:59:02 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A6FDD16A4CE for ; Thu, 12 Feb 2004 23:59:02 -0800 (PST) Received: from briefzentrum.encephalon.de (encephalon.de [213.146.112.85]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4D9BE43D1D for ; Thu, 12 Feb 2004 23:59:02 -0800 (PST) (envelope-from rosi@encephalon.de) Received: from encephalon.de (stella.bytecamp.net [212.204.60.37]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by briefzentrum.encephalon.de (Postfix) with ESMTP id 2C0851DD49 for ; Fri, 13 Feb 2004 09:01:24 +0100 (CET) Message-ID: <402C83D9.6000208@encephalon.de> Date: Fri, 13 Feb 2004 08:59:21 +0100 From: rosi User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.6b) Gecko/20040212 Thunderbird/0.4 X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd-current@freebsd.org Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: experiences using "options SCHED_ULE" X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Feb 2004 07:59:02 -0000 hello, i know ... [/usr/srs/sys/conf/NOTES...] # SCHED_ULE is a new experimental scheduler that has been designed for SMP, but will work just fine on UP too. Users of this scheduler should expect some hicups and be prepaired to provide feedback. [...] ... so here is the feedback. We using FreeBSD 5.2.1 p2 on SMP machines (i386 / Dual-P3 / Dual-Xeon). These servers running Apache+Suexec+PHP+Perl+Python and nfs(4). We were curiously in the new scheduler and so we test it. After building and installing the kernel (the only! thing that changed was "options SCHED_ULE") we see the system takes much more cpu time. CPU time in % usr sys idl options SCHED_ULE 20-25 60-75 0-20 options SCHED_4BSD 30-35 35-40 0-35 Also we "see" much more suexec and php processes (usually, you can't see them because they are processed to fast ;) ) and the whole system felt slowly. On the search for the reason why the machine takes so much cpu time for system, we found 400% to 500% more interrupts on the NIC's(fxp/em). After building and installing a new kernel using SCHED_4BSD, the whole system runs like always. Very fast and well. If it is necessary, i would post more informations. But i think the "problem" is reproducibly on i386 SMP machines. Naturally we will also test the SCHED_ULE again, if something changed. --- Frank rosi@encephalon.de