Re: [gentoo-user] date and gentoo running under vmplayer

[John J. Foster]

On Thu, Mar 06, 2008 at 08:00:00PM -0700, John J. Foster wrote:
> On Wed, Mar 05, 2008 at 08:25:59PM -0700, John J. Foster wrote:
> > Hi all - it's been awhile
> >
> > This past week I've set up Gentoo running in a VM built by
> > http://www.easyvmx.com/ under a XP host. Installation and configuration
> > went fine. I normally leave the VM running when I walk away from the
> > machine, but when I return, time is way off. Shutting down Gentoo & the
> > VM & rebooting solvles the problem, as vmplayer must initially get the
> > date and time from the host, but it sure doesn't keep it right after
> > that. I tried openntpd, but it kept setting the time further and further
> > off. I live in Fort Collins, Co and my locatime is set correctly
> > (America/Denver). This is my 1st time playing with VM's. Is this common?
> > Is there any way around it? I'm not really sure why openntpd didn't
> > work.
> >
> > Any and all help appreciated.
> >
> I need to explain this a little further, me thinks. My Gentoo VM is
> losing right around 20 seconds every minute! This is not a problem that
> ntp in any of its incarnations is designed to solve. A couple other
> thing I have tried are
>
> clock=pit noapic
>
> appended to the kernel command line. I tried these together and
> separately with no luck. Right now I'm trying another suggestion I
> found, which is to change the kernel frequency timer from 1000Hz to
> 250Hz. I'm recompiling now and will let you know.
>
Switching to 250Hz looks like it has solved the problem. No time lost
for a little over an hour now, and ntp is syncing properly, I think. But
my reading of the help on this setting led me to believe that 1000Hz was
right for a desktop system.

Can any explain what this setting actually does, and why it works now?

***** from make menuconfig help *****

CONFIG_HZ_1000:

1000 Hz is the preferred choice for desktop systems and other
systems requiring fast interactive responses to events.

Symbol: HZ_1000 [=n]
Prompt: 1000 HZ
  Defined at kernel/Kconfig.hz:42
  Depends on: <choice>
  Location:
    -> Processor type and features
      -> Timer frequency (<choice> [=y])