Re: [PATCH v4] sched/freq: move call to cpufreq_update_util

[Vincent Guittot]

On Fri, 15 Nov 2019 at 11:51, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Fri, Nov 15, 2019 at 11:46:01AM +0100, Vincent Guittot wrote:
> > On Fri, 15 Nov 2019 at 11:37, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> > > Sure, but then it can still remember the value passed in last and use
> > > that state later.
> > >
> > > It doesn't _have_ to completely discard values.
> >
> > yes but it means that we run at the "wrong" frequency during this
> > period and also that the cpufreq must in this case set a kind of timer
> > to resubmit a new frequency change out of scheduler event
>
> But if, as you say, we're completely shutting down the event stream
> when everything has decayed, that's still true, right?

But It doesn't because there is nothing else to do.

This patch does 2 things:
- fix the spurious call to cpufreq just before attaching a task
- make sure cpufreq is still called when cfs is 0 but not irq/rt or dl

There are somehow related but not fully