[arch-general] Many timers now running at boot. How to make them run later?

Ralph Corderoy ralph at inputplus.co.uk
Sat Nov 23 13:52:34 UTC 2019

Hi Chris,

> David C. Rankin wrote:
> > I wonder why systemd doesn't do this by default?
> It's not systemd to blame. The timer unit files are shipped by the
> respective projects, like util-linux, man-db, mlocate, shadow,
> logrotate, ...

systemd.timer(5) says

        Within this time window, the expiry time will be placed at a
        host-specific, randomized, but stable position that is
        synchronized between all local timer units.  This is done in
        order to optimize power consumption to suppress unnecessary CPU

So I think it is systemd's `fault' that they all collide.

I think its theory is flawed.  The CPU here will happily move from doing
nothing to doing slightly less for a unit and back again without getting
hot and altering the fan speed.  But ig the typical timer units collide
then the fan speed moves up through the gears and keeps going at more
than idle speed for some time, long after the units have finished and
the CPU clocked back down.  That must impact power consumption too.

Cheers, Ralph.

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