Date: Sun, 11 Feb 1996 10:14:10 +0100 From: Poul-Henning Kamp <phk@critter.tfs.com> To: Bruce Evans <bde@zeta.org.au> Cc: current@freebsd.org Subject: Re: calibrating clocks Message-ID: <6069.824030050@critter.tfs.com> In-Reply-To: Your message of "Sun, 11 Feb 1996 04:52:09 %2B1100." <199602101752.EAA05969@godzilla.zeta.org.au>
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> I plan to calibrate all the system clocks relative to the MC14618A (RTC) > clock and perhaps use the results automatically. Sample results on a > P133 for a sequence of calibrations run at boot time: Did you see the email about the "almost correct sub-tic" stunt ? Basically you count how many times microtime was called per tick, make a (short) running avg of it, and when people call microtime you just return the tick + a counter times that avg. For most if not all purposes this would be cheap and OK. Actually only high-precision profiling and NTP would need any better... -- Poul-Henning Kamp | phk@FreeBSD.ORG FreeBSD Core-team. http://www.freebsd.org/~phk | phk@login.dknet.dk Private mailbox. whois: [PHK] | phk@ref.tfs.com TRW Financial Systems, Inc. Future will arrive by its own means, progress not so.
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