On Wed, 12 Jul 2000, Linus Torvalds wrote:
> On Thu, 13 Jul 2000, Richard Gooch wrote:
> >
> > Er, so how many ticks do a nice 10 and a nice 11 process get,
> > respectively?
>
> Same number of ticks. The nice 10 one gets scheduled more
> eagerly, though (ie the "nice" level does more than just
> determine the number of ticks: it is also used to determine
> relative priorities if two processes have the same number of
> ticks to run).
>
> In 2.5.x we'll probably make the timer run at a higher rate,
> making this issue go away, but for 2.4.x this was the expedient
> way to maintain UNIX semantics and get good interactive
> behaviour.
Another possibility is to not give the 1 "extra" tick to
niced processes all the time.
#define NICE_TO_TICKS(nice) ((((20)-(nice)) >> (LOG2_HZ-5))+1)
If we make the "+1" a conditional thing, which is only given to
processes every ((20)-(nice) / nice) times - or even less - we
can have larger, maybe even tunable, differences between niced
tasks...
regards,
Rik
--
"What you're running that piece of shit Gnome?!?!"
-- Miguel de Icaza, UKUUG 2000
http://www.conectiva.com/ http://www.surriel.com/
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