Re: Delayed acpi frequency governor call

[Philipp Miedl <philipp.miedl@tik.ee.ethz.ch>]

> You are using a 4.4 kernel, which used the older delayed work stuff at sampling
> rate. This has all changed a lot and we hooks paired with the scheduler now to
> do this instead. Things have mostly changed since 4.7. Would it be possible for
> you to use a later kernel and see if you still see something wrong?
I switched to the latest stable kernel available, 4.9.5. Judging from 
the first test I ran, using this kernel I cannot
reproduce this behavior anymore. Looks like it has been fixed by the 
changes introduced.
> Now coming back to 4.4, the timers (in the delayed works) can't get delayed but
> the work can as it is just another process.
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?!
> But your setup has no almost load
> and that seems unlikely as well. So, it looks to be a problem at some other
> place. Tracers are your friend, only those can confirm something here.
Thanks for the tip with the tracers. If time allows I will have a look 
into that - I would like to know whats going
on, just out of curiosity.

-- 
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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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