Eric Saxe wrote: > Alexander Kolbasov wrote: >> Bill Holler <Bill.Holler at sun.com> wrote: >> >> >> Bill> It will be useful to have c-state information observable >> (including latency >> Bill> and power savings) during development and testing. Should >> c-state >> Bill> information be in a kstat such as the cpu_info kstat? >> >> Isn't c-state information extremely transient? I am wondering what value >> can you get if it is placed in kstats. IMO something like total time in >> various states might be more useful (if it is possible to obtain). >> > PowerTop conveys the total time in various c-states (over a given > sampling interval). I'm not sure how useful the "total time since the > system booted" would be, since that would probably include periods of > time where the system was busy. > > -Eric > My thoughts were that most cpus spend more time in an idle c-state than executing in a p-state.
Sounds like PowerTop has much of the c-state info. Latency and power- savings per c-state is probably not useful to users, and we can get at this groping around with mdb. Bill
