Re: Question about fair schedulers

From: Alberto Gonzalez
Date: Sat Jun 23 2007 - 04:01:37 EST


Thanks for your thoughts.

On Saturday 23 June 2007, Paolo Ornati wrote:
> On Sat, 23 Jun 2007 00:07:15 +0200
>
> Alberto Gonzalez wrote:
> > My conclusion is that SD behaves as expected: it's more fair. But for a
> > desktop, shouldn't an "intelligently unfair" scheduler be better?
>
> "intelligently unfair" is what the current scheduler is (because of
> interactivity estimator).
>
> When it works (say 90% of the time) the desktop feels really good...
> but when it doesn't it can be a disaster.

I see. So you mean that in 90% of the cases the mainline scheduler behaves
better than fair schedulers, but when its "logic" fails it behaves much worse
(the other 10% cases)? In my very simple test scenario the mainline scheduler
did behave much better. Maybe the problem comes with very complex scenarios
like the ones I've seen when testing these 2 fair schedulers (something like
compiling a kernel while you open 5 instances of glxgears, write an email,
play music in Amarok and watch 2 HD videos all at the same time). The
question would then be if these kind of situations are likely to happen in
real world, or even if it doesn't make more sense to try to improve the logic
of the mainline scheduler so that those 10% cases are handled better instead
of writing a new one that would behave worse in 90% of the cases and better
in the other 10%.

Alberto.
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