Re: [BISECTED] 2.6.35.*: horrible (exponential? >linear) slowdownto unusability (HPET)

[Thomas Gleixner]

On Fri, 10 Sep 2010, Thomas Gleixner wrote:
> On Fri, 10 Sep 2010, Nix wrote:
> > 
> > I suspect current_clocksource doesn't do what we think it does, or the
> > clocksource and 'clock event device' are not the same.)
> 
> Right, they are not the same. clocksource provides us a read out
> device for timekeeping (usually a simple increasing counter). clock
> event device is used to generate timer interrupts.
> 
> HPET provides both functionalities.
> 
> The patch you bisected is affecting the clock events part of the
> HPET. So yes, it's not a clock source problem.

Another question. If you add hpet=verbose (or revert that commit) does
the printk_once in hpet_set_next_event() show up in dmesg ?

    "hpet: compare register read back failed."

Thanks,

	tglx
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