Re: Interesting scheduling times - NOT
H. Peter Anvin (hpa@transmeta.com)
18 Sep 1998 18:08:03 GMT
Followup to: <199809180835.BAA30897@bitmover.com>
By author: lm@bitmover.com (Larry McVoy)
In newsgroup: linux.dev.kernel
>
> No it doesn't. Your test is broken, it doesn't measure what you think
> it measures. Your test depends on the schedulor doing the right thing
> (in your mind) when all you are doing is sched_yield(). You had a high
> priority process and a bucnh of low priority processes, all yielding to
> each other. My guess is that you thought the scheduler would resched
> the one high priority process back to itself. Under 2.0.33, at least,
> that doesn't happen. I think a lot of operating systems would take the
> yielding process out of the resched equation - as does Linux - so what
> you are doing is yielding to one of your low priority processes.
>
> This is trivial to see if you just run top while running your test, you
> can see the low priority processes getting cycles and they shouldn't be.
>
Would this work if the processes where SCHED_RR as opposed to normal
dynamic-priority processes?
-hpa
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