From owner-cvs-src@FreeBSD.ORG Fri Oct 21 16:25:06 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 84CDB16A41F; Fri, 21 Oct 2005 16:25:06 +0000 (GMT) (envelope-from bde@zeta.org.au) Received: from mailout1.pacific.net.au (mailout1.pacific.net.au [61.8.0.84]) by mx1.FreeBSD.org (Postfix) with ESMTP id D4A4143D45; Fri, 21 Oct 2005 16:25:05 +0000 (GMT) (envelope-from bde@zeta.org.au) Received: from mailproxy2.pacific.net.au (mailproxy2.pacific.net.au [61.8.0.87]) by mailout1.pacific.net.au (8.13.4/8.13.4/Debian-3) with ESMTP id j9LGP4r1016527; Sat, 22 Oct 2005 02:25:04 +1000 Received: from katana.zip.com.au (katana.zip.com.au [61.8.7.246]) by mailproxy2.pacific.net.au (8.13.4/8.13.4/Debian-3) with ESMTP id j9LGP1d9019340; Sat, 22 Oct 2005 02:25:02 +1000 Date: Sat, 22 Oct 2005 02:25:01 +1000 (EST) From: Bruce Evans X-X-Sender: bde@delplex.bde.org To: Poul-Henning Kamp In-Reply-To: <30805.1129910750@critter.freebsd.dk> Message-ID: <20051022021817.X5902@delplex.bde.org> References: <30805.1129910750@critter.freebsd.dk> 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 16:25:06 -0000 On Fri, 21 Oct 2005, Poul-Henning Kamp wrote: > In message <20051022011020.T5554@delplex.bde.org>, Bruce Evans writes: > >> How do you resync laptops after suspending them for long enough for >> the clock to drift? Use ntpd and let it step, or use ntpd -x and let >> it take hours to resync? The right thing to do is step the clocks to >> the current time immediately so that they are correct while the system >> is actually being used. > > Ahh, and now we get into interesting territory: What _is_ the > definition of uptime for a laptop which has been suspended ? > > No matter which way you turn, there are dragons... >> I certainly care about errors of 1 microsecond (although I don't need >> to), and just remembered that I use stepping to fix up the clock after >> sitting in ddb with the clock stopped. This reduces the error in the >> real time clock to ~1 microsecond per second stopped, but gives an error >> of 1 second per second stopped in the monotonic time and the boot time. >> Here the correct treatment is to jump the monotonic time forward and >> not touch the boot time. > > Again, if you have been sitting in DDB, what exactly is the definition > of "uptime" ? This is clear. The system is up while it is sitting in ddb. It's actually more active then average then, since doesn't idle or halt :-). Bruce