On 3 June 2013 16:27, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > The question is if we want policy->max to re-scale them effectively (i.e. to > change weights so that the maximum load maps to the highest frequency available > at the moment) or if we want policy->max to work as a cap (i.e. to map all > loads above certain value to the maximum frequency available at the moment, so > that the criteria for selecting the lower frequencies don't change). In my > opinion the second option is better, because it means "OK, we can't use some > high frequencies, but let's not hurt performance for the loads that wouldn't > require them anyway". Otherwise, we'll effectively throttle all loads and > that not only causes performance to drop, but also causes more energy to be > used overall. I wouldn't say that I don't agree with you as I do to some extent. But the question that comes to my mind now is: Why is policy->max reduced in the first place? User doesn't have control over which freqs to expose, so available_frequencies will stay the same. The only thing he is capable of doing is: reduce policy->max.. Which in a way means that.. "I don't want to use higher frequencies (power, thermal reasons) and I know performance will go down with it and I don't care for it now." And this way I feel policy->max isn't a bad choice either. BUT as you said: policy->max isn't there to say don't be so aggressive now in increasing frequencies but just only to say, don't go over this frequency.. So, probably we can use cpuinfo.max_freq :) -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
