[ntp:questions] Power-saving patch to NTP

Evandro Menezes evandro at mailinator.com
Fri May 16 19:04:08 UTC 2008


On May 15, 9:28 pm, "David L. Mills" <mi... at udel.edu> wrote:
>
> A timer interrupt is required each second to update the clock frequency
> no matter what. In addition, a sweep is made through the associations to
> see if a poll is pending. It would be in principle posssible to
> implement a system of queues to avopid sweeping the associations each
> second, but that would save very few cycles, add some more cycles and
> additional complexity.

NTP could set a reminder for itself not for the next second, in case
there's a poll pending, but for the minimum period left among all
polled servers.  This would be pretty simple and power-friendly.

Mind you, a CPU uses orders of magnitude less power in a stand-by
state, even a simple halt-instruction, than running.  See page 3 of
http://download.intel.com/technology/itj/2006/volume10issue02/vol10_art03.pdf
for more info.

HTH




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