Messages in this thread | | | Date | Thu, 13 Jul 2000 12:36:19 -0300 (BRST) | From | Rik van Riel <> | Subject | Re: Report: Big Improvement in -test3 |
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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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