Messages in this thread | | | Date | Tue, 6 Apr 2010 07:45:59 +0530 | From | Balbir Singh <> | Subject | Re: [RFC][PATCH] sched: cpuacct: Track cpuusage per cpu frequency |
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* menage@google.com <menage@google.com> [2010-04-05 12:52:57]:
> On Mon, Apr 5, 2010 at 12:33 PM, Mike Chan <mike@android.com> wrote: > > New file: cpuacct.cpufreq when CONFIG_CPU_FREQ_STATS is enabled. > > > > cpuacct.cpufreq accounts for cpu time per-cpu frequency, time is exported > > in nano-seconds > > Can you clarify the wording of this (and describe it in the relevant > Documentation/... file)? It's not clear. > > From the code, it appears that the file reports a breakdown of how > much CPU time the cgroup has been consuming at each different CPU > frequency level. If so, then you probably want to reword the > description to avoid "per-cpu", since that makes it sounds as though > it's reporting something, well, "per CPU". > > Also, what's the motivation here? If it's for power monitoring > purposes, might it be simpler to just report a single number, that's > the integral of the CPU usage by frequency index (i.e. calculated from > the same information that this patch is already gathering in > cpuacct_charge()) rather than dumping a whole table on userspace?
As utilization increases, won't the integral quickly overflow? BTW, Mike have you looked at the scaled accounting infrastructure we have in taskstats?
-- Three Cheers, Balbir
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