On Tue, 9 Jan 2024 at 12:56, Dietmar Eggemann <dietmar.eggemann@xxxxxxx> wrote: > > On 08/01/2024 14:48, Vincent Guittot wrote: > > Now that cpufreq provides a pressure value to the scheduler, rename > > I.e. that thermal (e.g. IPA governor) switches from average > (rq->avg_(thermal/hw).load_avg) (1) to instantenous (cpu_pressure) (2). > I rememeber a related dicussion during LPC 2018 :-) > > > arch_update_thermal_pressure into HW pressure to reflect that it returns > > a pressure applied by HW (i.e. with a high frequency change) and not > > always related to thermal mitigation but also generated by max current > > limitation as an example. Such high frequency signal needs filtering to be > > smoothed and provide an value that reflects the average available capacity > > into the scheduler time scale. > > So 'drivers/cpufreq/qcom-cpufreq-hw.c' is the only user of (1) right > now. Are we expecting more users here? If this stays the only user, > maybe it can do the averages by itself and we can completely switch to (2)? Yes I expect more users for this high frequency change which is typically 1ms and below. And I prefer to keep PELT averaging calculation inside scheduler instead of letting driver doing their own averaging which will be most of the time not aligned with what scheduler wants > > [...] >
