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

From: Stefano Brivio
Date: Thu Nov 29 2007 - 15:21:19 EST


On Thu, 29 Nov 2007 20:36:24 +0100
Ingo Molnar <mingo@xxxxxxx> 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
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