Messages in this thread | | | Subject | Re: sched: ARM: arch_scale_freq_power | From | Peter Zijlstra <> | Date | Tue, 11 Oct 2011 11:13:19 +0200 |
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On Tue, 2011-10-11 at 10:51 +0200, Vincent Guittot wrote: > I have several goals. The 1st one is that I need to put more load on > some cpus when I have packages with different cpu frequency.
That should be rather easy.
> I also study if I can follow the real cpu frequency but it seems to be > not so easy.
Why not?
> I have noticed that the cpu_power is updated periodical > except when we have a lot of newly_idle events.
We can certainly fix that.
> Then, I have some use cases which have several running tasks but a low > cpu load. In this case, the small tasks are spread on several cpu by > the load_balance whereas they could be easily handled by one cpu > without significant performance modification.
That shouldn't be done using cpu_power, we have sched_smt_power_savings and sched_mc_power_savings for stuff like that.
Although I would really like to kill all those different sched_*_power_savings knobs and reduce it to one.
> If the cpu_power is > higher than 1024, the cpu is no more seen out of capacity by the > load_balance as soon as a short process is running and teh main result > is that the small tasks will stay on the same cpu. This configuration > is mainly usefull for ARM dual core system when we want to power gate > one cpu. I use cyclictest to simulate such use case.
Yeah, but that's wrong.
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