Re: Bug: timer going backward on a dual core

[john stultz <johnstul@us.ibm.com>]

On Fri, 2005-10-28 at 23:39 +0200, Claudio Scordino wrote:
> On Friday 28 October 2005 22:43, john stultz wrote:
> > On Fri, 2005-10-28 at 22:27 +0200, Claudio Scordino wrote:
> > > > > We have a dual-core AMD64 with the new kernel 2.6.14 and the
> > > > > timer goes backward...
> > > > >
> > > > >
> > > > > CONFIGURATION:
> > > > >
> > > > > Kernel: 2.6.14
> > > > > Distribution: Gentoo Linux 2005.0
> > > > > Processor: Athlon 64 x2 4200+ (dual core)
> > > > > Motherboard: Abit KN8
> > > > > Memory: 1GB PC3200
> > > > >
> > > > >
> > > > > PROBLEM:
> > > > >
> > > > > gettimeofday goes backward and returns values that are not monotonic,
> > > > > giving values that are smaller than values returned before.
> > > > >
> > > > > The system has been tested with timer as PIT, PIT/TSC and PM and the
> > > > > problem occurs with all the configurations.
> > > > >
> > > > > Here is the config file that we used for the PM configuration.
> > > > >
> > > > > Any suggestion ?
> > > >
> > > > Booting w/ idle=poll tends to work around this issue. You might check
> > > > with your motherboard vendor for an updated BIOS that supports HPET or
> > > > the ACPI PM timer.
> > >
> > > We already updated the BIOS with the latest version.
> > >
> > > Also the booting command idle=poll doesn't work.
> >
> > Hmm. Not sure then. Is this a new regression on the same hardware?
> 
> Yes, we tried with idle=poll and the problem occurred again.

Sorry for the confusion, I meant if the problem is new to 2.6.14, or if
it also happened with 2.6.13?

> > Would you mind filing a bug (http://bugzilla.kernel.org )on this and
> > attaching your config and dmesg there?
> 
> Sure.

Please assign it to me or add me to the cc list.

thanks
-john

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