On Thu, Mar 10, 2016 at 05:23:54PM +0700, Vincent Guittot wrote: > > No, since its a compile time thing, we can simply do: > > > > #ifdef arch_scale_freq_capacity > > next_freq = (1 + 1/n) * max_freq * (util / max) > > #else > > next_freq = (1 + 1/n) * current_freq * (util_raw / max) > > #endif > > selecting formula at compilation is clearly better. I wrongly thought that > it can't be accepted as a solution.
Well, its bound to get more 'interesting' since I forse implementations not always actually doing the invariant thing. Take for example the thing I send: lkml.kernel.org/r/20160303162829.gb6...@twins.programming.kicks-ass.net it both shows why you cannot talk about current_freq but also that the above needs a little more help (for the !X86_FEATURE_APERFMPERF case). But the !arch_scale_freq_capacity case should indeed be that simple.
