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I'm on kernel 3.16.0-29-lowlatency on 

cpu family  : 6
model       : 55
model name  : Intel(R) Pentium(R) CPU  N3540  @ 2.16GHz

Unfortunately as the entire /sys/devices/system/cpu/cpu0/cpufreq/stats directory is missing so is the time_in_state file I'm looking for.

Why is the directory gone? How do I get it back? Are there other means of CPU frequency tracking?

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up vote 1 down vote

You're not going to like this answer: You can choose between low-latency or monitoring.

Why?

Well, to be able to make a low-latency kernel, some things are taken out of the kernel..

That being said, this is open source, so if you really want to have CPU frequency tracking in a low-latency kernel, build your own kernel and #undefine a few #define statements!

Hint: grep --directories=recurse --ignore-case latency linux-3.18.3/* | grep --ignore-case "#define"

(Yeah, I only looked through the most recent stable kernel, not yours...)

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And it's not because you don't like an answer that you should forget to click the grey check-mark under the "0" at the left of this text, which means "yes, this answer is valid"! ;-) – Fabby Jan 22 '15 at 13:46
up vote 1 down vote accepted

This does not have anything to do with the kernel being a lowlatency flavour. It's intel_pstate cpufreq driver which does not implement statistics. You can disable it via intel_pstate=disable in the kernel command line, but you don't really want to as this will cause more energy usage.

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