Wierd time changes

[Mark Ovens]

Denis R. wrote:
> Hi Mark and list members,
> 
> I am experiencing the same problem on my dual PII-450 SP700 Compaq Pro
> workstation. After poking around on Google, it is pointing to the FreeBSD
> and a i8254 programmable interupt timer. In my case the time is lagging
> behind 10 times! What does your:
> #time sleep 10
> show?

redshift# time sleep 10
0.000u 0.001s 0:10.00 0.0%      0+0k 0+0io 0pf+0w
redshift#

The clock maintains the correct time whilst FreeBSD is running, it just 
suddenly changes, at least somewhere "inside" FreeBSD, during shutdown 
but doesn't screw the system clock until the next reboot, and even after 
that it maintains consistent, but incorrect, time; i.e. it doesn't gain 
or lose at a steady rate.

Regards,

Mark

> It takes 25 seconds on my SMP workstation to execute a 10 second delay. I
> have modified the /etc/sysctl.conf and added:
> kern.timecounter.hardware=i8254
> 
> ntpd couldn't cope with this problem on my server. I have to run ntpdate
> every 10 minutes to set the time to an approximately accepted value :-(.
> 
> There used to be a problem on older releases of FreeBSD (4.2 and up)
> related to a SMP kernel and clock. Someone posted a hack fix of the:
> usr/src/sys/i386/isa/clock.c file. But apparently it has been fixed in
> newer releases and does not get mentioned in 5.x.
> 
> The most common fix I've heard from people is to recompile the kernel and
> exclude the SMP support. But if this is the case, I'd be switching to a
> mono CPU support of OpenBSD to run it. One of the reasons I like FreeBSD
> is its SMP support.
> 
> People, any ideas?
> 
> dmesg part:
> MPTable: <COMPAQ   Workstation >
> Timecounter "i8254" frequency 1193182 Hz quality 0
> uname -a:
> FreeBSD 5.2-RELEASE FreeBSD 5.2-RELEASE #0: Sun Jan 11 04:21:45 GMT 2004  
>   root at wv1u.btc.adaptec.com:/usr/obj/usr/src/sys/GENERIC  i386
> 
> Thanks and regards!
> Denis
> 
> 
>>>>>>>>>>>>>>>>
> I'm completely baffled by this one. When FreeBSD shuts down/reboots it
> changes the system clock. It *always* sets the hours to 20 and changes
> the minutes and seconds (but I haven't worked out a pattern for that),
> but the date stays the same (see /var/log/messages below) although I
> once saw it keep the time and date correct, but set the year back *four*
> years(!) but that was when the correct time was 22:mm:ss.
> 
> 
> _______________________________________________
> freebsd-questions at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> To unsubscribe, send any mail to "freebsd-questions-unsubscribe at freebsd.org"
> 
> .
>