Messages in this thread | | | Date | Thu, 21 Jan 1999 12:05:11 +0100 (CET) | From | Rik van Riel <> | Subject | Re: Scheduler problems |
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On Wed, 20 Jan 1999, Stephen C. Tweedie wrote: > On Tue, 19 Jan 1999 20:43:12 +0100 (CET), MOLNAR Ingo > <mingo@chiara.csoma.elte.hu> said: > > On Tue, 19 Jan 1999, Stephen C. Tweedie wrote: > > > yes i have a patch for this but it's not straightforward enough for 2.2. > > (ie. a 50k patch) It has to do things like a full goodness() run for every > > CPU in wakeup(), which is less than ideal. > > Ingo, before I read this I was thinking about it a little and yes, this > was one of the issues which worried me. However, is there any reason > why we can't just use the last known goodness of the process currently > running on each CPU, rather than recalculating the current goodness?
The biggest problem is that p->counter is essentially a random value because of the gross recalculation done in the schedule() function.
If we were to use a more smoothed out recalculation [p->counter = (((p->counter * 7) + p->priority + 7) / 8);] then we could just use p->counter without ever having to do any expensive recalculations.
regards,
Rik -- If a Microsoft product fails, who do you sue? +-------------------------------------------------------------------+ | Linux memory management tour guide. riel@nl.linux.org | | Scouting Vries cubscout leader. http://www.nl.linux.org/~riel | +-------------------------------------------------------------------+
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