Messages in this thread | | | Date | Tue, 15 Jan 2002 21:35:10 +0100 (CET) | From | Ingo Molnar <> | Subject | [patch] O(1) scheduler, -I1 |
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On Tue, 15 Jan 2002, Davide Libenzi wrote:
> > - RT scheduling is broken. > > Why ?
RR tasks were queued to the expired array.
> [...] Ingo, IMHO is not correct to give time slices depending on > priority and we should return to the old TS(nice) behavior.
i agree - but your new patch is broken still, you have the timeslice range inverted(!) :-)
but never mind, i've fixed this and added the code to -I1, check it out at:
http://redhat.com/~mingo/O(1)-scheduler/sched-O1-2.5.2-final-I1.patch
(for the record, i've tested -I1 on SMP and UP as well.)
-I1 also includes a fix from Dave Jones: mmu_context.h was still included in arch/i386/kernel/process.c.
> [...] IMVHO is not correct to have new tasks to fully inherit parent > priority because :
i fully agree - in -I0 i have kept the 'child gets 10% less priority than parent' rule. This works really well in fork-bomb situations, i've tested this with -I0. (and -I1 as well.) It also works well with interactive shells, which want to start processes which will inherit *some* of their parent's priority, but not all of it.
> 2) if an interactive task is born we do not need an immediate priority > boost
Think about starting a simple 'ls' under X if under some high load. This works just fine under 2.5.2-vanilla and 2.5.2-I0 as well. We should give the task a chance to finish within ... 500 or 1000 msecs (or so), most shell commands that fork do so.
> 3) if a cpu bound task born from an interactive task ( very very common ) > it'll make a long run on the cpu before falling in the hell of cpu > bound tasks > > I've also decreased the minimum time slice to 10ms and increased the > max to 160ms and this should cast back niced tasks to low cpu usages.
(i've done this already in -I0, based on earlier comments of yours.)
> I'm using it in my desk and just to have fun i keep running make -j20 > in background:-)
please re-test this with -I1. (i've tested it and it works just fine, but more testing cannot hurt.)
are there any other items in your patch that are not yet in -I1?
Ingo
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