F7 K6-2 system losing time

[Todd Denniston]

Kevin Cummings wrote, On 03/24/2008 12:13 AM:
> I'm playing with an old motherboard of mine.  Its an AMD K6-2 500MHz 
> processor, w/384MB PC-100 SDRam (Max amount).  Its running the latest F7 
> kernel, and its losing time.  Almost 15 seconds / minute (ouch!).  This 
> motherboard used to run my main home server, running on RH9 & FC2 
> without any problems with its timekeeping.  Now that I'm playing with F7 
> on it in a *very* minimal system (few server services, X11, nfs, but no 
> http, no email, etc) its losing time big-time.  Even running ntpd can't 
> keep up with it.  In fact, it re-syncs to the correct time only when I 
> restart ntpd.
> 
> Anyone have a clue as what's wrong with it?
> 

I would try booting with the fedora rescue disk,
don't let it mount any file systems or connect up the network.
then set the system time from your watch as a source.
after a few minutes (should be long enough with the delta you are seeing 
above) ask the system for the time (`date`)
if it is not significantly different then I would expect you are getting a 
bunch of thrashing of an PATA disk while normally running.
Please note my bias: with an older version of the OS ~FC1|2, I had a laptop 
with a PCMCIA network card (i.e. network on PATA bus basically) and it's 
system time would get totally whacked out during high network traffic and it 
was worse when that traffic was also being written to the PATA hard drive. 
Not sure if the new Lib ATA has stopped disabling the timer interrupt or not.
Or look for other things that disable the timer interrupt in the kernel.

if it is significantly different ... time to have fun :)

-- 
Todd Denniston
Crane Division, Naval Surface Warfare Center (NSWC Crane)
Harnessing the Power of Technology for the Warfighter