Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt

Arjan van de Ven
2005-07-11T14:12:18Z

> The real answer here is for the tickless patches to cleaned up to the
> point where they can be merged, and then we won't waste battery power
> entering the timer interrupt in the first place. :-)

one big step forward for that is to have a

mod_timer_relative() and add_timer_relative()

which
1) take a relative delay as argument (and thus kill 99% of the jiffies
use in the kernel right there and then)
2) takes it in miliseconds, killing 99% of all the HZ conversions/uses
3) takes a "accuracy" argument

3) is tricky I guess, it's designed for cases that are like "I want a
timer 1 second from now, but it's ok to be also at 1.5 seconds if that
suits you better". Those cases are far less rare than you might think at
first, most watchdog kind things are of this type. This accuracy thing
will allow the kernel to save many wakeups by grouping them I suspect.

Alan: you worked on this before, where did you end up with ?