Architecture specific implementations for tickless kernel and deferrable timers

[Vikram Narayanan]

On Wed, Apr 27, 2011 at 1:47 PM, Thomas Gleixner <tglx at linutronix.de> wrote:
> On Wed, 27 Apr 2011, Vikram Narayanan wrote:
>> On Wed, Apr 27, 2011 at 2:07 AM, Russell King - ARM Linux
>> > The only way to have a stable time source is to have a stable clocksource
>> > - one which is never stopped or otherwise messed around with.  If you
>> > try to combine clocksource and clockevent with one-shot mode, where
>> > the clocksource part is reset each time a new event is set, you'll probably
>> > soon end up with time going screwy.
>> >
>> Thanks for the insight.
>> My another question is that, where can I find some examples of dynamic
>> tick implementation. Are there any documents for implementing the
>> functionality?
>> Also the struct dyn_tick_timer in the file include/asm-arm/mach/time.h
>> is removed since 2.6.27. So how do I achieve this?
>> If you refer me to some documentation on this, that would be great.
>
> Provide a functional clocksource plus a clockevent device which is
> oneshot capable. Enable CONFIG_NOHZ and there you go.
>
I am still confused about the terms clocksource and clockevents. Can
someone please explain it in simple terms or lead me to a good
documentation that elaborates clearly about this?

Thanks,
Vikram
> Thanks,
>
>        tglx