From owner-freebsd-net@FreeBSD.ORG Wed Sep 13 17:49:46 2006 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9BCA916A407; Wed, 13 Sep 2006 17:49:46 +0000 (UTC) (envelope-from mike@sentex.net) Received: from smarthost1.sentex.ca (smarthost1.sentex.ca [64.7.153.18]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2D11B43D70; Wed, 13 Sep 2006 17:49:45 +0000 (GMT) (envelope-from mike@sentex.net) Received: from lava.sentex.ca (pyroxene.sentex.ca [199.212.134.18]) by smarthost1.sentex.ca (8.13.6/8.13.6) with ESMTP id k8DHni6U039282; Wed, 13 Sep 2006 13:49:44 -0400 (EDT) (envelope-from mike@sentex.net) Received: from mdt-xp.sentex.net (simeon.sentex.ca [192.168.43.27]) by lava.sentex.ca (8.13.6/8.13.3) with ESMTP id k8DHnihK057510 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 13 Sep 2006 13:49:44 -0400 (EDT) (envelope-from mike@sentex.net) Message-Id: <7.0.1.0.0.20060913134509.159096f0@sentex.net> X-Mailer: QUALCOMM Windows Eudora Version 7.0.1.0 Date: Wed, 13 Sep 2006 13:49:44 -0400 To: Robert Watson From: Mike Tancsa In-Reply-To: <20060913182457.W50147@fledge.watson.org> References: <2a41acea0608301145j7bbed961j33ce903a27d8963d@mail.gmail.com> <20060904130827.GE12975@registro.br> <20060911195521.GD63300@registro.br> <20060913182019.R50147@fledge.watson.org> <20060913182457.W50147@fledge.watson.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed X-Virus-Scanned: ClamAV version 0.88.3, clamav-milter version 0.88.3 on clamscanner2 X-Virus-Status: Clean Cc: freebsd-net@freebsd.org, freebsd-stable@freebsd.org Subject: Re: DNS query performance X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 Sep 2006 17:49:46 -0000 At 01:27 PM 9/13/2006, Robert Watson wrote: >The other common optimization advice that you may already have >received is to check which time counter FreeBSD has selected. Right >now, 6.x/7.x err on the side of accurate over fast. There's been >quite a bit of debate about this approach, and it's useful to >investigate the issue. You can view and set the current choice by >looking at the sysctl kern.timecounter.hardware, and you can see the >choices on your hardware by looking at kern.timecounter.choice. >Typically, TSC is the fastest, but may suffer from drift as the CPU changes Hi, How safe is TSC on SMP systems on RELENG_6 ? Do you still have to boot with kern.timecounter.smp_tsc="1" in /boot/loader.conf ? I was able to set it to TSC on my SMP box # sysctl kern.timecounter kern.timecounter.tick: 1 kern.timecounter.choice: TSC(-100) ACPI-fast(1000) i8254(0) dummy(-1000000) kern.timecounter.hardware: TSC kern.timecounter.nsetclock: 4 kern.timecounter.ngetmicrotime: 1710689523 kern.timecounter.ngetnanotime: 0 kern.timecounter.ngetbintime: 0 kern.timecounter.ngetmicrouptime: 417696361 kern.timecounter.ngetnanouptime: 6622371 kern.timecounter.ngetbinuptime: 17943777 kern.timecounter.nmicrotime: 2454574760 kern.timecounter.nnanotime: 1315721638 kern.timecounter.nbintime: 3770262461 kern.timecounter.nmicrouptime: 407340 kern.timecounter.nnanouptime: 1397760 kern.timecounter.nbinuptime: 3787035688 kern.timecounter.stepwarnings: 0 kern.timecounter.smp_tsc: 0 But the console fills up with Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335379728 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335379758 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335379789 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335379819 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335379849 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335379879 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335379910 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335379940 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335379970 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380002 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380032 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380065 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380096 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380126 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380156 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380186 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380216 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380247 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380277 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380307 usec for pid 66442 (clamd) Sep 13 13:47:57 pumice1 kernel: calcru: runtime went backwards from 6336196518 usec to 6335380337 usec for pid 66442 (clamd) So I set things back to kern.timecounter.hardware: ACPI-fast ---Mike