Date: Thu, 23 Oct 1997 18:53:26 +1000 From: Bruce Evans <bde@zeta.org.au> To: freebsd-hackers@FreeBSD.ORG, freebsd-stable@FreeBSD.ORG, joes@seaport.net Subject: Re: Interesting behaviour from sysctl(kern.boottime) Message-ID: <199710230853.SAA29257@godzilla.zeta.org.au>
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>But, I've come to notice the following: (five executions worth of data:) > >----------------- cut here -------------- >System time is (877528801) Wed Oct 22 07:00:01 1997 >System Booted at (877407594) Mon Oct 20 21:19:54 1997 > ^^^^^^^^^^^^^^^^^^^ >Difference is: 121207 seconds >----- >System time is (877532401) Wed Oct 22 08:00:01 1997 >System Booted at (877407591) Mon Oct 20 21:19:51 1997 > ^^^^^^^^^^^^^^^^^^^ >Difference is: 124810 seconds >----- >... >I run xntpd. Could that be a factor? (updating the clock ticks or whatever?) Yes, it changes the boot time whenever it calls settimeofday() to step the clock. settimeofday() always adjusts `boottime' when it adjust `time'. This is correct when both were wrong originally, but completely wrong if the clock has drifted. A drift of 3 seconds per day is good if xntpd is _not_ used, but xntpd not step the clock if it is correctly configured and the system is always connected. Bruce
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