[Xenomai] Set CPU Clock Frequency

Mauro Salvini mauro.salvini at smigroup.net
Tue Feb 28 08:12:34 CET 2017


Another way to do this is to configure kernel with CPU_FREQ on and with
all frequency governors disabled except the performance one, or if you
prefer with all governors enabled and performance one set as default
governor (instead on-demand).
Kernel will boot with default frequency and will change it to the
maximum only one time during boot process, when cpufreq driver will be
loaded.

On Mon, 2017-02-27 at 11:38 -0800, Steve B wrote:
> In my application, turning CPU_FREQ off defaulted the CPU to a frequency
> that we didn't want (we wanted 100% but it for some reason set us to  a
> lower one). The other problem is that in some cases our application would
> intermittently freak out and lock things up if the frequency changed in the
> background.
> 
> What I did was leave the frequency scaling on, and then I went into the
> device tree and removed all of the options except the one we wanted.
> Depending on how your OS distribution is set up you may be able to do the
> same!
> 
> Steve
> 
> 
> On Fri, Feb 17, 2017 at 7:24 AM, Philippe Gerum <rpm at xenomai.org> wrote:
> 
> > On 02/17/2017 03:38 PM, mobin.motallebizadeh at gmail.com wrote:
> > > Hi
> > > As we are disabling CPU_FREQ system consumes as much energy as it can
> > and it’s undesirable.
> > >
> > > Is there any method to set cpu clock freq to something other than 100%?
> > >
> > > Something like letting CPU_FREQ=y and setting clock freq manually by
> > cpufreq utility and then re-calibrate the cobalt core. I don’t know. Just
> > guessing!
> >
> > There is no provision for this.
> >
> > --
> > Philippe.
> >
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> >
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