periodically save current time to time-of-day hardware

Andriy Gapon avg at
Fri Mar 26 15:53:54 UTC 2010

on 26/03/2010 17:44 Dag-Erling Smørgrav said the following:
> Andriy Gapon <avg at> writes:
>> What do you think about the following patch or something similar?
> I've wondered for years why we didn't already do this.
>> Also, I am aware that the period should be configurable (sysctl).
> Why?

Because there would always be someone who would want a different value :)

> Although I can see an argument for a sysctl to turn it on or off.

Good idea.

> IIRC, Linux saves the clock at shutdown, and every 11 minutes if and
> only if the system clock is synchronized to an external reference.

Both are good ideas too.
I know how to add a shutdown hook (event handler), but I don't know how to check
if time synchronization is taking place.

Andriy Gapon

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