From owner-freebsd-current Mon Nov 6 12:37:53 1995 Return-Path: owner-current Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id MAA12506 for current-outgoing; Mon, 6 Nov 1995 12:37:53 -0800 Received: from zibbi.mikom.csir.co.za (zibbi.mikom.csir.co.za [146.64.24.58]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id MAA12499 for ; Mon, 6 Nov 1995 12:37:46 -0800 Received: (from jhay@localhost) by zibbi.mikom.csir.co.za (8.6.12/8.6.9) id WAA14154; Mon, 6 Nov 1995 22:34:49 +0200 From: John Hay Message-Id: <199511062034.WAA14154@zibbi.mikom.csir.co.za> Subject: Re: Time problems To: bde@zeta.org.au (Bruce Evans) Date: Mon, 6 Nov 1995 22:34:49 +0200 (SAT) Cc: freebsd-current@FreeBSD.ORG (FreeBSD-current) In-Reply-To: <199511062022.HAA30357@godzilla.zeta.org.au> from "Bruce Evans" at Nov 7, 95 07:22:11 am X-Mailer: ELM [version 2.4 PL23] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 902 Sender: owner-current@FreeBSD.ORG Precedence: bulk > >> > >I ran your program with the pentium timer disabled and regularly got > >> > >negative numbers. The numbers vary, but things that I got was -6, -38, > >> > >-44, -17, etc... > >> > > >> > You would need similar delays in microtime() for the non-pentium version > >> > to work. Try adding such delays (`inb $0x84, %al' immediately after the > >> > outb). > >> I tried a few combinations up to two inb's after the outb and after the first > >> inb, but I still get negative numbers. I also tried Garrett's program and > >> apart from it coredumping sometimes the min value is always a negative number > >> -99 and worse. > > Is this with xntpd or similar slewing the clock? I would expect only > large errors of 10000 usec if the heuristic for handling counter overflow > doesn't work. > No I booted in single user mode, so nothing else was running. John -- John Hay -- John.Hay@csir.co.za