Date: Wed, 7 Apr 1999 12:24:29 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: Don Lewis <Don.Lewis@tsc.tdk.com> Cc: Nick Sayer <nsayer@FreeBSD.ORG>, cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/sys/kern kern_time.c Message-ID: <199904071924.MAA05436@apollo.backplane.com> References: <199904071917.MAA16146@salsa.gv.tsc.tdk.com>
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:On Apr 7, 9:36am, Nick Sayer wrote:
:} Subject: cvs commit: src/sys/kern kern_time.c
:
:} We still need to decide on an algorithm to clamp positive adjustments.
:} As it stands, it is possible to achieve arbitrary negative adjustments
:} by "wrapping" time around.
:
:Limit positive steps to MIN(1 second, elapsed time since last postive step).
:At worst the clock could be made to run at 2x normal speed.
:
: --- Truck
That's a pretty good solution. If this is combined with calling
'ntpdate' on boot to step the time prior to starting xntpd, I think
we wind up with quite a reasonable setup. Once stepped, xntpd isn't
likely to have to do anything major. Besides, in order to be 'safe'
from PC realtime clock chip Y2K issues you pretty much have to step
the time by syncing it to an external source with ntpdate on boot
anyway.
-Matt
Matthew Dillon
<dillon@backplane.com>
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