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Re: Speaking of ntp, yes CD-R does mess with the clock!

On Sun, Dec 22, 2002 at 10:32:43AM -0800, Bill Moseley wrote:
> On Sun, 22 Dec 2002, Shawn Lamson wrote:
> > >   date; burn-cd.sh; date
> > > 
> > > and burning the CD using cdrdao (48x drive -- about 4 minutes to burn a
> > > CD) caused the system clock to fall behind about *50* seconds.
> > > 
> > > Maybe it's because the CD-R is so fast?  "Let's do the time warp again!"
> > 
> > This is why I installed rdate, I think it is b/c it is so processor
> > intensive (CD-R).  I didn't read the entire previous thread on ntp,
> > but rdate at least does the trick for my single user system.
> Just seems really odd.  Interrupts still happen, right?  And to drop 50
> seconds in 4 minutes just doesn't seem like a matter of the machine being
> too busy to keep time.
> Weird.  I need to have him see if it does the same thing with other
> burning programs, or when ripping.

The stupid driver might cli interrupts for long periods of time
which would cause time interrupts to get missed especially if
it disables the interrupts for more than 1/18th (or something
like that - well, this is from my old "MSDOS" memory days
so the number is probably different now) of a second then
you could have two interrupts happen when the interrupts
are disabled and there is the time warp. Interrupts
should never get disabled for that long. It's a bug if you
ask me....

- Adam

PS. Wow, that's one run on sentence!

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