From owner-cvs-src@FreeBSD.ORG Fri Oct 21 14:31:44 2005 Return-Path: X-Original-To: cvs-src@FreeBSD.org Delivered-To: cvs-src@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DC0AF16A41F; Fri, 21 Oct 2005 14:31:44 +0000 (GMT) (envelope-from bde@zeta.org.au) Received: from mailout2.pacific.net.au (mailout2.pacific.net.au [61.8.0.115]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3CAD843D48; Fri, 21 Oct 2005 14:31:44 +0000 (GMT) (envelope-from bde@zeta.org.au) Received: from mailproxy1.pacific.net.au (mailproxy1.pacific.net.au [61.8.0.86]) by mailout2.pacific.net.au (8.13.4/8.13.4/Debian-3) with ESMTP id j9LEVhUR016348; Sat, 22 Oct 2005 00:31:43 +1000 Received: from katana.zip.com.au (katana.zip.com.au [61.8.7.246]) by mailproxy1.pacific.net.au (8.13.4/8.13.4/Debian-3) with ESMTP id j9LEVfe6022257; Sat, 22 Oct 2005 00:31:41 +1000 Date: Sat, 22 Oct 2005 00:31:41 +1000 (EST) From: Bruce Evans X-X-Sender: bde@delplex.bde.org To: Poul-Henning Kamp In-Reply-To: <20051021230751.Q5110@delplex.bde.org> Message-ID: <20051022002904.P5334@delplex.bde.org> References: <27345.1129842256@critter.freebsd.dk> <20051021230751.Q5110@delplex.bde.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, Andre Oppermann , cvs-all@FreeBSD.org Subject: Re: Timekeeping [Was: Re: cvs commit: src/usr.bin/vmstat vmstat.c src/usr.bin/w w.c] X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Oct 2005 14:31:45 -0000 On Sat, 22 Oct 2005, Bruce Evans wrote: > On Thu, 20 Oct 2005, Poul-Henning Kamp wrote: >> In summary: CLOCK_MONOTONIC is our best estimate of how many SI >> seconds the system have been runing [3]. > > Actual testing shows that CLOCK_MONOTONIC, or possibly CLOCK_REALTIME > less the boot time, gives a very bad estimate of how long the system has > been running. The difference between these clocks was about 500 seconds > on all systems tested: > > % sledge: > % 1:03PM up 22:45, 1 user, load averages: 0.23, 0.08, 0.02 > % uptime 1 81900 > % uptime 2 82887 > ... > A large fairly machdine-independent differece is hard to explain. I > will reboot after sending this to see if one of the values is much > larger than the uptime when the uptime is < 60 seconds. Please ignore this. It was a stupid bug. After fixing the bug, there were no differences. Bruce