system clock going backward

[Jay Cliburn]

Ali Sobhi wrote:
> Folks,
> I'm facing a strange situation on my systems running FC5 and my research 
> has resulted in some information which I'm not about.
> I've to mention that this problem showed up with FC5 and was not there 
> when FC4 was running.
> 
> The system clock is misbehaving and sometimes goes backward. No ntpd 
> running (read on)
[snip]
> where should I go from here?
> should I disable "acpid"?
> should I use "pmtmr_good" boot parameter?
> should I disable power management functions of the BIOS? (this is desktop 
> model)
> which log file to look at to figure out what is going on?

I picked up a surplus IBM Net Vista 8308 last week (ICH4/82801DB chipset), and 
lo and behold, I saw the same clock weirdness you reported.  There's a 
smattering of similar reports on the web spread across all distros.  The best 
description of the issue is in the source code itself.  Take a look at the file 
arch/i386/kernel/timers/timer_pm.c.

It seems to keep time okay if I boot with noapic, but I'm trying a different 
option at the moment:  clock=tsc.  I'll let you know if it works out.

Jay