Re: [BUG] jiffies counter leaps in 2.6.24-rc3

[Stefano Brivio <stefano.brivio@polimi.it>]

On Thu, 29 Nov 2007 20:36:24 +0100
Ingo Molnar <mingo@elte.hu> wrote:

> just to make sure there is no tsc impact, does booting with "notsc" 
> change anything?

No, it doesn't.

> if not, does booting with idle=halt or idle=poll help? [your power usage 
> will go up so it's not very useful - but it could help exclude a few 
> sources of trouble.]

With idle=poll nothing changes, except that - as soon as I switch the CPU
frequency - I get this in the logs:

[  297.562722] Marking TSC unstable due to: cpufreq changes.
[  297.566677] Time: acpi_pm clocksource has been installed.

With idle=halt, changing frequency just freezes the system. I can't even use
the magic Sys Rq keys then.

I observed another thing. When I don't use any of the parameters you
suggested for debugging, I get this at boot:

[    6.530752] Marking TSC unstable due to: possible TSC halt in C2.
[    6.530761] Time: acpi_pm clocksource has been installed.
[    6.620700] Clocksource tsc unstable (delta = -456217276 ns)


-- 
Ciao
Stefano