Op Saturday 17 March 2007, schreef Ingo Molnar:
quoted text
> * jos poortvliet <jos@mijnkamer.nl> wrote:
> > Op Saturday 17 March 2007, schreef Ingo Molnar:
> > > so it is not at all clear to me that RSDL is indeed an improvement,
> > > if it does not have comparable auto-nice properties.
> >
> > Wasn't the point of RSDL to get rid of the auto-nice, because it
> > caused starvation, unpredictable behaviour and other problems?
>
> it doesnt really get rid of it, it replaces it with another mechanism
> that is fundamentally unfair too.
>
> RSDL has _another_, albeit more hidden "auto-nice" behavior: this time
> expressed not via the plain manipulation of priorities based on the
> sleep average, but expressed via the quota-depletion flux of tasks over
> time, fed into a complex dance of rotating priorities - which
> quota-depletion flux is in essence a sleep average too, just more
> derived and more hardcoded.

Hmmm. I wonder, then, does RSDL give an advantage in the areas I mentioned=
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(starvation and predictability)?=20

RSDL does give equal timeslices (eg equal cpu time) to each process - it's=
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just that processes which didn't use their time yet can quickly run, right?=
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Now I might not understand things here, but that it sounds more fair, thoug=
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you're more quallified to judge that. So, for me, as an user, it boils down=
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to: does this solve problems, and does it introduce problems?

I must say I compare RSDL to staircase, as that's what I'm used to - a bit=
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more interactive compared to mainline. RSDL does slightly worse AND slightl=
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better - worse in interactivity on heavy loads (8 makes running on my=20
dualcore) but it doesn't have the systemwide stalls sometimes occurring on=
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both mainline and staircase - though it replaces them with shorter,=20
app-specific ones (the worse interactivity I mention).

quoted text
> or looking at it from another angle, code size:
>
>    text    data     bss     dec     hex filename
>   15750      24    6008   21782    5516 sched.o.vanilla
>   15960     360    6336   22656    5880 sched.o.rsdl
>
> there's no reduction in complexity, it just moved elsewhere.
>
> 	Ingo



=2D-=20
Disclaimer:

Alles wat ik doe denk en zeg is gebaseerd op het wereldbeeld wat ik nu heb.=
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Ik ben niet verantwoordelijk voor wijzigingen van de wereld, of het beeld w=
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ik daarvan heb, noch voor de daaruit voortvloeiende gedragingen van mezelf.=
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Alles wat ik zeg is aardig bedoeld, tenzij expliciet vermeld.