Hi, On Tuesday, October 23, 2012 06:30:49 PM Pawel Moll wrote: > Greetings All, > > More and more of people are getting interested in the subject of power > (energy) consumption monitoring. We have some external tools like > "battery simulators", energy probes etc., but some targets can measure > their power usage on their own. > > Traditionally such data should be exposed to the user via hwmon sysfs > interface, and that's exactly what I did for "my" platform - I have > a /sys/class/hwmon/hwmon*/device/energy*_input and this was good > enough to draw pretty graphs in userspace. Everyone was happy... > > Now I am getting new requests to do more with this data. In particular > I'm asked how to add such information to ftrace/perf output. Why? What is the gain? Perf events can be triggered at any point in the kernel. A cpufreq event is triggered when the frequency gets changed. CPU idle events are triggered when the kernel requests to enter an idle state or exits one. When would you trigger a thermal or a power event? There is the possibility of (critical) thermal limits. But if I understand this correctly you want this for debugging and I guess you have everything interesting one can do with temperature values: - read the temperature - draw some nice graphs from the results Hm, I guess I know what you want to do: In your temperature/energy graph, you want to have some dots when relevant HW states (frequency, sleep states, DDR power,...) changed. Then you are able to see the effects over a timeline. So you have to bring the existing frequency/idle perf events together with temperature readings Cleanest solution could be to enhance the exisiting userspace apps (pytimechart/perf timechart) and let them add another line (temperature/energy), but the data would not come from perf, but from sysfs/hwmon. Not sure whether this works out with the timechart tools. Anyway, this sounds like a userspace only problem. Thomas _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
