Accessing the phyBOARD-Wega Interfaces
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PHYTEC Messtechnik GmbH 2014 L-792e_1
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The result will be:
conservative
userspace
powersave
ondemand
performance
.
conservative
is much like the
ondemand
governor. It differs in behavior in that it
gracefully increases and decreases the CPU speed rather than jumping to
max speed the moment there is any load on the CPU.
userspace
allows the user or userspace program running as root to set a specific
frequency (e.g. to 600000). Type:
echo
600000
>
/sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
powersave
always selects the lowest possible CPU core frequency.
ondemand
switches between possible CPU core frequencies in reference to the current
system load. When the system load increases above a specific limit it
increases the CPU core frequency immediately. This is the default governor
when the system starts up.
performance
always selects the highest possible CPU core frequency.
In order to ask for the current governor, type
cat
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
and you will normally get:
ondemand
.
Switching over to another governor (e.g.
userspace
) is done with:
echo
userspace
>
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
For more detailed information about the govenors refer to the
Linux
kernel documentation
in:
Documentation/cpu-freq/governors.txt
.
