Re: [PATCH 2/4] nohz: Synchronize sleep time stats with seqlock

From: Frederic Weisbecker
Date: Tue Aug 20 2013 - 11:35:40 EST


On Tue, Aug 20, 2013 at 08:33:50AM -0700, Arjan van de Ven wrote:
> On 8/20/2013 8:29 AM, Frederic Weisbecker wrote:
>
> >>
> >>Of course, if we can get away with completely removing all of that
> >>(which I think Arjan suggested was a real possibility) then that would
> >>be ever so much better still :-)
> >
> >Would be lovely. But I don't know much about cpufreq, I hope somebody who's
> >familiar with that code can handle this. Then once there are no more users
> >of get_cpu_iowait_sleep_time() I can simply zap and clean the tick/time related
> >code.
>
> it's just doing the "idle = 100 - busy% - iowait%" calculation.
> (with the later part only for Intel cpus iirc)
>
> in a perfect world the scheduler would be doing that calculation in the first place ;-)
>
> removing the later part will impact performance some on specific workloads,
> but most Intel cpus that this applies to should not be using cpufreq anymore
> anyway.

Are there other users than intel?
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