From owner-freebsd-questions@FreeBSD.ORG Mon Nov 22 23:27:56 2004 Return-Path: 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 0D25E16A4CE for ; Mon, 22 Nov 2004 23:27:56 +0000 (GMT) Received: from hobbiton.shire.net (hobbiton.shire.net [166.70.252.250]) by mx1.FreeBSD.org (Postfix) with ESMTP id D739F43D39 for ; Mon, 22 Nov 2004 23:27:55 +0000 (GMT) (envelope-from chad@shire.net) Received: from [67.161.247.57] (helo=[192.168.99.66]) by hobbiton.shire.net with esmtpsa (TLSv1:RC4-SHA:128) (Exim 4.43) id 1CWNb9-00090G-EA for freebsd-questions@freebsd.org; Mon, 22 Nov 2004 16:27:55 -0700 Mime-Version: 1.0 (Apple Message framework v619) Message-Id: <20F05A1A-3CDE-11D9-BC47-003065A70D30@shire.net> To: FreeBSD questions list From: "Chad Leigh -- Shire.Net LLC" Date: Mon, 22 Nov 2004 16:27:51 -0700 X-Mailer: Apple Mail (2.619) X-SA-Exim-Connect-IP: 67.161.247.57 X-SA-Exim-Mail-From: chad@shire.net Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; format=flowed X-Spam-Checker-Version: SpamAssassin 3.0.0 (2004-09-13) on hobbiton.shire.net X-Spam-Status: No, score=-0.3 required=5.0 tests=AWL,BAYES_50 autolearn=disabled version=3.0.0 X-Spam-Level: X-SA-Exim-Version: 4.1+cvs (built Mon, 23 Aug 2004 08:44:05 -0700) X-SA-Exim-Scanned: Yes (on hobbiton.shire.net) Subject: HZ kernel option X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Nov 2004 23:27:56 -0000 Hi Ok, I am trying to get a feel for the "HZ" option in the 5.3 (RELENG_5) kernel config. # The granularity of operation is controlled by the kernel option HZ whose # default value (100) means a granularity of 10ms (1s/HZ). options HZ=100 For a machine that is running as a server, running apache, roxen, exim, php, some java (server stuff), perl, and then ssh command line stuff, what is a general recommendation for this parameter? One of the docs mentions that for some network stuff like dummynet, increasing this (making the quantum slice smaller) can give better performance. Can that be extrapolated to general network server stuff like apache, roxen, exim, etc? What have people found out in playing with this??? Thanks Chad