Re: [SHED] Questions.

[Nick Piggin <piggin@cyberone.com.au>]

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