[LAU] Problems with real time kernel, thermal throttling and cpu freq governors.

[Harry van Haaren]

On Thu, Sep 25, 2014 at 4:13 AM, Rafael Vega <email.rafa at gmail.com> wrote:
> In short, when running the RT kernel from Debian Jessie repos
> (3.14-2-rt-amd64), the scaling governor cannot be changed and the system
> hangs if the cpu temperature reaches the thermal throttling threshold.

I've been noticing the issue of not being able to change frequency
governer on -rt kernels here. I've posted to the -rt mailing list,
details here (click "next in thread" to follow convo):
http://marc.info/?l=linux-rt-users&m=140897493204106&w=2

In short, there seems to be something going wrong with locking /
unlocking an RW lock that is used during a CPU freq scaling. I have
pin-pointed the issue to a pretty specific place in
<kernel>/drivers/cpufreq/cpufreq.c  but I don't know how to fix it.

Note that I'm running 3.14.12-rt9-1-rt (Arch linux, from AUR) but the
issue seems identical to me..

I have an older CPU (Core2Duo from about 7 years ago), but I read in
the forum link you have an i7? That shouldn't have the same issue...

I'll post to the -RT list, mentioning your email, and you system
config, and see if the devs there think they're releated or different.

Cheers, -Harry

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