My Haswell CPU uses, by default, intel_pstate to do the frequency scaling.
I have been able to disable that in /etc/defaults/grub so that it drops down to acpi-cpufreq driver.
However, I want to disable that one too, so that my system will use speedstep-lib instead.
The speedstep driver is available on my system as a module:
$ ls -1 /usr/lib/modules/`uname -r`/kernel/drivers/cpufreq
amd_freq_sensitivity.ko
p4-clockmod.ko
speedstep-lib.ko
How can I force the kernel to use the speedstep frequency scaling?
NOTE: The reason for wanting to do this, as that neither intel_pstate nor acpi-cpufreq can scale individual cores for this CPU. If it scales the frequency, those drivers always do that for all cores in unison. Never one core clocked high, another core clocked low. I want to find out if speedstep-lib can do this, or if the CPU simply does not have the capability, period.
UPDATE
I have been unable to find out how to disable acpi-cpufreq.
But I did find out that switching the speedstep-lib is not going to help me:
All active processor IA cores share the same frequency and voltage. In a multicore processor, the highest frequency P-state requested among all active IA cores is selected.
