Re: armhf current clock speed? big secret, very high vacuum

[Diego Roversi <diegor@tiscali.it>]

On Sat, 8 Apr 2017 10:27:04 -0400
Gene Heskett <gheskett@shentel.net> wrote:

> 
> Unforch the kernel, Linux raspberrypi 4.4.4-rt9-v7+ #7 SMP PREEMPT RT, is 
> currently locked because its an rt-prempt kernel, absolutely needed for 
> the target application, which is LinuxCNC. Is there a newer kernel with 
> those irq response time mods?

The "standard" and lowlevel way is to look in this directory:

/sys/devices/system/cpu/cpu0/cpufreq/

They are not real files, but just a way to ask to kernel the information you need. From a terminal, as superuser, you can check min and max clock speed (# -> is the terminal prompt):

# cd /sys/devices/system/cpu/cpu0/cpufreq/
# cat scaling_min_freq
# cat scaling_max_freq

To see the current speed:

# cat scaling_cur_freq 

I also recommend to use the "performance" scaling governor, so the cpu is always at max speed (scaling_max_freq). ie:

# echo "performance" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

I hope it helps. Some more informations are found at this page: https://wiki.debian.org/HowTo/CpuFrequencyScaling

-- 
Diego Roversi <diegor@tiscali.it>