Messages in this thread | | | Date | Fri, 15 Nov 2019 12:56:37 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v4] sched/freq: move call to cpufreq_update_util |
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On Fri, Nov 15, 2019 at 12:03:31PM +0100, Vincent Guittot wrote: > On Fri, 15 Nov 2019 at 11:51, Peter Zijlstra <peterz@infradead.org> 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@infradead.org> 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
Right, but when everything is 0, we stop generating events because we stop calling update_blocked_average(), so there will be a last event when we hit all 0s and then nothing.
So no superfluous events.
And if that last event if thrown out because of rate-limiting ....
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