Messages in this thread |  | | Subject | Re: [PATCH 3/5] scheduler: cpuacct: Enable platform hooks to track cpuusage for CPU frequencies | From | Peter Zijlstra <> | Date | Sat, 20 Nov 2010 11:48:24 +0100 |
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On Fri, 2010-11-19 at 18:08 -0800, John Stultz wrote: > From: Mike Chan <mike@android.com> > > Introduce new platform callback hooks for cpuacct for tracking CPU frequencies > > Not all platforms / architectures have a set CPU_FREQ_TABLE defined > for CPU transition speeds. In order to track time spent in at various > CPU frequencies, we enable platform callbacks from cpuacct for this accounting. > > Architectures that support overclock boosting, or don't have pre-defined > frequency tables can implement their own bucketing system that makes sense > given their cpufreq scaling abilities. > > New file: > cpuacct.cpufreq reports the CPU time (in nanoseconds) spent at each CPU > frequency.
I utterly detest all such accounting crap.. it adds ABI constraints it add runtime overhead. etc..
Can't you get the same information by using the various perf bits? If you trace the cpufreq changes you can compute the time spend in each power state, if you additionally trace the sched_switch you can compute it for each task.
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