Messages in this thread | | | Date | Wed, 18 Jun 2003 14:16:22 +0200 | From | Helge Hafting <> | Subject | Re: O(1) scheduler starvation |
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Mike Galbraith wrote: > At 09:53 AM 6/18/2003 +0200, Felipe Alfaro Solana wrote: > >> Hi! >> >> I've been poking around and found the following link on O(1) scheduler >> starvation problems: >> >> http://www.hpl.hp.com/research/linux/kernel/o1-starve.php >> >> The web page contains a small test program which supposedly is able to >> make two processes starvate. However, I've been unable to reproduce what >> is described in the above link. In fact, the CPU usage ratio ranges >> between 60-40% or 70-30% in the worst cases. > > > (you're talking about with my monotinic_clock() diff in your kernel right?) > > If you examine the priorities vs cpu usage, therein lies a big fat bug. > > I think the fundamental problem is that you can only execute in series, > but can sleep in parallel, which makes for more sleep time existing than > all execution time combined.
Would dividing the sleep time by the number of sleepers fix this? Or is division a too heavy operation here?
Helge Hafting
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