On Fri, Jan 18, 2019 at 11:34 AM Quentin Perret <quentin.perret@xxxxxxx> wrote: > > Hi Rafael, > > On Friday 18 Jan 2019 at 10:57:08 (+0100), Rafael J. Wysocki wrote: > > On Fri, Jan 18, 2019 at 10:16 AM Quentin Perret <quentin.perret@xxxxxxx> wrote: > > > > > > Hi Juri, > > > > > > On Thursday 17 Jan 2019 at 16:51:17 (+0100), Juri Lelli wrote: > > > > On 10/01/19 11:05, Quentin Perret wrote: > > > [...] > > > > > +The idea behind introducing an EM is to allow the scheduler to evaluate the > > > > > +implications of its decisions rather than blindly applying energy-saving > > > > > +techniques that may have positive effects only on some platforms. At the same > > > > > +time, the EM must be as simple as possible to minimize the scheduler latency > > > > > +impact. > > > > > + > > > > > +In short, EAS changes the way CFS tasks are assigned to CPUs. When it is time > > > > > > > > Not sure if we want to remark the fact that EAS is looking at CFS tasks > > > > only ATM. > > > > > > Oh, what's wrong about mentioning it ? I mean, it is a fact ATM ... > > > > But it won't hurt to mention that it may cover other scheduling > > classes in the future. IOW, the scope limit is not fundamental. > > Agreed, I can do that. > > > > > > +for the scheduler to decide where a task should run (during wake-up), the EM > > > > > +is used to break the tie between several good CPU candidates and pick the one > > > > > +that is predicted to yield the best energy consumption without harming the > > > > > +system's throughput. The predictions made by EAS rely on specific elements of > > > > > +knowledge about the platform's topology, which include the 'capacity' of CPUs, > > > > > > > > Add a reference to DT bindings docs defining 'capacity' (or define it > > > > somewhere)? > > > > > > Right, I can mention this is defined in the next section. But are you > > > sure about the reference to the DT bindings ? They're arm-specific right ? > > > Maybe I can give that as an example or something ... > > > > Example sounds right. > > > > You also can point to the section below from here. > > Sounds good. > > > Side note: If the doc is in the .rst format (which Peter won't like > > I'm sure :-)), you can actually use cross-references in it and you get > > a translation to an HTML doc (hosted at kernel.org) for free and the > > cross-references become clickable links in that. > > Right, I personally don't mind the .rst format, but the existing files > in Documentation/power/ and Documentation/scheduler/ are good old txt > files so I just wanted to keep things consistent. In fact, Documentation/power/ is under a slow on-going transition to .rst (due to the benefits mentioned above). > I don't mind converting to rst if necessary :-) It is not necessary, but maybe worth considering.
