On 25.01.2017 04:23, Viresh Kumar wrote:

On 24-01-17, 15:49, Philipp Miedl wrote:

quoted

Can you please describe how things changed from version 4.4 to 4.9 - I'm not
sure if I understand correctly.
Before 4.7 the governor was just running as a kernel process and triggered
by the (free running) timers and
now its hooked with the scheduler. So the scheduler ensures that the
governor work is not delayed?!

Now the cpufreq callbacks gets called from within the scheduler every few
milliseconds. And once we have crossed the sampling-rate time, we reevaluate the
frequency. Though ondemand/conservative governors still used workqueue until
very recently for most of the platforms. Recently it is replaced by a RT thread.

Ok got it now. Thanks a lot for your help!

-- 
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|  Philipp Miedl                                                   |
|  PhD Student @ Computer Engineering and Networks Laboratory      |
|  ETH Zurich, ETZG76, Gloriastrasse 35, 8092 Zurich, Switzerland  |
|  mail: philipp.miedl@ee.tik.ethz.ch      phone: +41 44 632 70 61 |
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