Re: Timer unstability on when using C2 and deeper sleep states (Dell Latitude XT)

[Andi Kleen]

Milan Plzik <milan.plzik@xxxxxxxxx> writes:

>   I apologize for replying on my own mail (and also for top-posting, but
> this information is global update, not exactly fitting any of topics
> mentioned below).
>
>   After playing for a longer while I found out that the system ends
> sometimes in state where, in order to do anything useful, I need to
> press keys on keyboard. 

This usually means it is using the wrong timer in a deeper idle state.
Some idle states cannot be woken up by e.g. the APIC timer and then
you get that effect: you only make progress when you wake up the 
CPU in some other way like pressing a key. Then on wake up the
timers get processed.

This is usually a bug in the kernel timer selection. It should be chosing
a timer that always wakes up from the deepest idle state used.

You should post the full boot log

-Andi

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