From owner-freebsd-arch@FreeBSD.ORG Wed Nov 17 22:03:11 2004 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7AB2316A4CE for ; Wed, 17 Nov 2004 22:03:11 +0000 (GMT) Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id 11BAD43D45 for ; Wed, 17 Nov 2004 22:03:09 +0000 (GMT) (envelope-from gallatin@cs.duke.edu) Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu [152.3.145.30]) by duke.cs.duke.edu (8.12.10/8.12.10) with ESMTP id iAHM38t7002055 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 17 Nov 2004 17:03:08 -0500 (EST) Received: (from gallatin@localhost) by grasshopper.cs.duke.edu (8.12.9p2/8.12.9/Submit) id iAHM32Y5001458; Wed, 17 Nov 2004 17:03:02 -0500 (EST) (envelope-from gallatin) From: Andrew Gallatin MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16795.51862.698490.378530@grasshopper.cs.duke.edu> Date: Wed, 17 Nov 2004 17:03:02 -0500 (EST) To: Poul-Henning Kamp In-Reply-To: <39210.1099557885@critter.freebsd.dk> References: <39210.1099557885@critter.freebsd.dk> X-Mailer: VM 6.75 under 21.1 (patch 12) "Channel Islands" XEmacs Lucid cc: arch@freebsd.org Subject: Re: HEADSUP: HZ=1000 by default on i386 X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Nov 2004 22:03:11 -0000 Poul-Henning Kamp writes: > > We increasingly need better granularity in our sleep/wakeup calls and > things like device polling and trafic shaping needs higher granularity > in particular. > Have you (or anybody else) looked at what dragonfly has done with tvtohz() and clock aliasing? The results presented at http://www.dragonflybsd.org/docs/nanosleep look very promising. But I've never thought very hard about timers, and I'm not sure I understand what they are doing. Drew