On 05-Dec 16:24, Juri Lelli wrote: > On 05/12/17 15:09, Patrick Bellasi wrote: > > > + /* > > > + * Ideally we would like to set util_dl as min/guaranteed freq and > > > + * util_cfs + util_dl as requested freq. However, cpufreq is not yet > > > + * ready for such an interface. So, we only do the latter for now. > > > + */ > > > > Maybe I don't completely get the above comment, but to me it is not > > really required. > > > > When you say that "util_dl" should be set to a min/guaranteed freq > > are you not actually talking about a DL implementation detail? > > > > From the cpufreq standpoint instead, we should always set a capacity > > which can accommodate util_dl + util_cfs. > > It's more for platforms which supports such combination of values for > frequency requests (CPPC like, AFAIU). The idea being that util_dl is > what the system has to always guarantee, but it could go up to the sum > if feasible.
I see, you mean for systems where you can specify both values at the same time, i.e. - please give me util_dl... - ... but if you have more beer, I would like util_dl + util_cfs However, I'm not an expert, on those systems can we really set a minimum guaranteed performance level? I was more of the idea that the "minimum guaranteed" is something we can only read from "firmware", while we can only ask for something which is never "guaranteed". > > We don't care about the meaning of util_dl and we should always assume > > (by default) that the signal is properly updated by the scheduling > > class... which unfortunately does not always happen for CFS. > > -- #include <best/regards.h> Patrick Bellasi
