On Thu, Mar 3, 2016 at 5:47 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > On Thu, Mar 03, 2016 at 05:37:35PM +0100, Peter Zijlstra wrote: >> On Thu, Mar 03, 2016 at 05:24:32PM +0100, Rafael J. Wysocki wrote: >> > >> f = a * x + b > >> > If not, then I think it's reasonable to map the middle of the >> > available frequency range to x = 0.5 and then we have b = 0 and a = >> > (max_freq + min_freq) / 2. That actually should be a = max_freq + min_freq, because I want (max_freq + min_freq) / 2 = a / 2. >> So I really think that approach falls apart on the low util bits, you >> effectively always run above min speed, even if min is already vstly >> over provisioned. > > Ah nevermind, I cannot read. Yes that is worth trying I suppose. But the > b=0,a=1 thing seems more natural still. It is somewhat imbalanced, though. If all of the values of x are equally probable (or equally frequent), the probability of running above the middle frequency is lower than the probability of running below it. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
