tickless cron

[Rogelio Serrano]

On 9/1/06, Natanael Copa <natanael.copa at gmail.com> wrote:
> On Fri, 2006-09-01 at 11:39 +0800, Rogelio Serrano wrote:
> > is it possible to have tickless cron?
>
> Everything is possible. The impossible just take a little more time.
>
> > given a cron format schedule string can we compute the exact time of
> > the next timeout?
>
> It is possible, but the question is if you want that. You would also
> like to check if your crontab(s) has changed. But ofcourse, you could
> use inotify for that.
>
> > the only algorithm i can come up with lists the exact day hour minute
> > time and daily, weekly or monthly repetition specifier.
>

what i mean is not have cron set a timer to one minute and evaluating
all the schedules once a minute. the present crontab format works well
in that mode becaue its just a straight comparison with the present
time and the values in a crontab line which can actually be placed in
a 'struct time'. what i would like to have is for cron to set the
timer exactly to the next timeout. i have a tickless kernel and it
does not make sense for cron the do exactly what i just removed from
the kernel.

maybe the crontab compatible schedule just cannot be made to work in
tickless mode.

-- 
things i hate about my linux pc:

1. it takes more than a second to boot up
2. keeps asking about filenames and directories
3. does not remember what i was working on yesterday
4. does not remember all the changes i have ever made
5.cannot figure out necessary settings by itself