Re: [patch] CFS scheduler, -v5

From: Ingo Molnar
Date: Mon Apr 23 2007 - 05:26:38 EST



* Nick Piggin <npiggin@xxxxxxx> wrote:

> > yeah - but they'll all be quad core, so the SMP timeslice
> > multiplicator should do the trick. Most of the CFS testers use
> > single-CPU systems.
>
> But desktop users could have have quad thread and even 8 thread CPUs
> soon, [...]

SMT is indeed an issue, so i think what should be used to scale
timeslices isnt num_online_cpus(), but the sum of all CPU's ->cpu_power
value (scaled down by SCHED_LOAD_SCALE). That way if the thread is not a
'full CPU', then the scaling will be proportionally smaller. Can you see
any hole in that?

Ingo
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