We put these numbers in sysfs because ACPI had them. Unfortunately, the ACPI numbers are not useful. Subsequently, cpuidle changes what these numbers means. They are an instantaneous relative ranking, not a real power number. We should remove them from sysfs.
thanks, -Len > -----Original Message----- > From: discuss-boun...@lesswatts.org [mailto:discuss-boun...@lesswatts.org] On > Behalf Of Sundar > Sent: Sunday, November 20, 2011 9:11 PM > To: k...@kenobrien.org > Cc: discuss@lesswatts.org > Subject: Re: [Discuss] cpuidle readouts > > > On Sun, Nov 20, 2011 at 8:08 PM, k...@kenobrien.org <k...@kenobrien.org> > > wrote: > > Ok, well is there a way to measure total CPU power consumption? Maybe by > > reading sysfs? > > > > Hi, > > You will need some extensive characterization (and measurement) of the > core power w.r.t the CPU frequency and the C-state residencies. > > You could create a table of the power consumption based on the core > frequency; and then individual residencies at that frequency; you > should discount all the state beyond the C-state for the CPU when > clock gating comes into effect, if your core supports clock gating at > all. Say for example, running at the lowest frequency constrained to a > 100% CPU utilization might be the number for starters. > > Cheers! > > -- > --------- > The views expressed in this email are personal and do not necessarily > echo my employers. > _______________________________________________ > Discuss mailing list > Discuss@lesswatts.org > http://lists.lesswatts.org/listinfo/discuss _______________________________________________ Discuss mailing list Discuss@lesswatts.org http://lists.lesswatts.org/listinfo/discuss
