Re: [PATCH] dynamic tick patch

From: Pavel Machek
Date: Wed Jan 19 2005 - 04:45:36 EST


Hi!

> Attached is the dynamic tick patch for x86 to play with
> as I promised in few threads earlier on this list.[1][2]
>
> The dynamic tick patch does following:
>
> - Separates timer interrupts from updating system time
>
> - Allows updating time from other interrupts in addition
> to timer interrupt
>
> - Makes timer tick dynamic
>
> - Allows power management modules to take advantage of the
> idle time inbetween skipped ticks
>
> - Might help with the whistling caps?
>
> The patch should be non-intrusive where possible. The system
> boots with the regular timers, and then later on switches on
> the dynamic tick if the selected driver implements get_hw_time()
> function.
>
> Currently supported timers are TSC and ACPI PM timer. Other
> timers should be easy to add. Both TSC and ACPI PM timer
> rely on the PIT timer for interrupts, so the maximum skip
> inbetween ticks is only few seconds at most.
>
> Please note that this patch alone does not help much with
> power savings. More work is needed in that area to make the
> system take advantage of the idle time inbetween the skipped
> ticks.

Well, having HZ=100 instead of HZ=1000 has measurable benefits on
power consumption. This should be at least as good, no?
Pavel
--
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!
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