Re: [SHED] Questions.

[Nick Piggin]

Ian Kumlien wrote:

> On Tue, 2003-09-02 at 13:08, Nick Piggin wrote:
>
> > Ian Kumlien wrote:
> >
> > > You could say that the problem the current scheduler has is that it's
> > > not allowed to starve anything, thats why we add stuff to give
> > > interactive bonus. But if it *was* allowed to starve but gave bonus to
> > > the starved processes that would make most of the interactive detection
> > > useless (yes, we still need the "didn't use their timeslice" bit and
> > > with a timeslice that gets smaller the higher the pri we'd automagically
> > > balance most processes).
> > >
> > > (As usual my assumptions might be really wrong...)
> > First off, no general purpose scheduler should allow starvation depending
> > on your definition. The interactivity stuff, and even dynamic priorities
> > allow short term unfairness.
>
> When you reach a certain load you *have to* allow starvation. Ie, you
> can't work around it... All i say is that if we have a more relaxed
> method we might benefit from it.

Depending on your definition. If 1000 processes get 10ms CPU every
10000ms I would not call that being starved. Maybe thats misleading.

> > Hmm... what else? The "didn't use their timeslice" thing is not
> > applicable: a new timeslice doesn't get handed out until the previous one
> > is used. The priorities thing is done based on how much sleeping the
> > process does.
>
> And not the amount of cpu consumed by the app / go?

Well yeah in a way. Consuming CPU lowers priority, sleeping raises.

> > Its funny, everyone seems to have very similar ideas that they are
> > expressing by describing different implementations they have in mind.
>
> Yes =), I'm mailing Con directly now as well, to save some unwanted
> traffic here =). I just hope that we'll reach a agreement somewhere
> about whats sane or not...
>
> Mail me if you're interested as well.

OK CC me

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