Ubuntu UME does not have GV3. cpufreq is not present in the folder /sys/devices/system/cpu/cpu0.
Tested with 8.04.1a, 8.04PV(updated to 2.6.24-19), RC2(2.6.24-18-lpia) and Beta4(2.6.24.16-lpia). All versions of UME does not have GV3.
Checked config-2.6.24-18-lpia, CONFIG_X86_SPEEDSTEP_CENTRINO=m and CONFIG_X86_SPEEDSTEP_CENTRINO_TABLE=y
cpufreq_ondemand.ko and freq_table.ko are available in /lib/modules/2.6.24-*-lpia/kernel/drivers/cpufreq, but both modules are NOT loaded during system boot.
Tried to modprobe cpufreq_ondemand.ko and both modules get loaded. But Enhanced Intel Speed Technology (GV3 or EIST) still not working, don't see the scaling frequency table folder "cpufreq" in /sys/devices/system/cpu/cpu*
UME will run only Lowest Frequency (Ratio 0x6)without EIST.
Without the feature enabled, CPU frequency will not change and always stays at minimum CPU frequency. If UME has this working, the CPU frequency will change up/down according to the workload or user-select depends on what scaling governor is being chosen.
This means that a customer will never be running the CPU at the rated frequency, i.e. the frequency he bought the part at. For example a 1.0Ghz Silverthone part will only be running at 0.6Ghz.
upon boot, /proc/cpuinfo shows two logical CPUs with:
model name : Genuine Intel(R) CPU @ 1.33GHz
cpu MHz : 1330.060
I launched powertop and saw:
Cn Avg residency P-states (frequencies)
C0 (cpu running) ( 1.7%)
C1 0.0ms ( 0.0%)
C2 0.2ms ( 0.0%)
C3 0.6ms ( 0.0%)
C4 20.8ms (98.3%)
so effectively C states are changing, and not P states (frequency).
I think this is thanks to the cpuidle driver (acpi_idle).
I loaded acpi-cpufreq, and as soon as it was loaded I got /sys/devices/
scaling_governor:
ondemand
cpuinfo_cur_freq:
800000
and /proc/cpuinfo would then say:
model name : Genuine Intel(R) CPU @ 1.33GHz
cpu MHz : 800.000
and powertop:
Cn Avg residency P-states (frequencies)
C0 (cpu running) ( 2.0%) 1333 Mhz 0.0%
C1 0.0ms ( 0.0%) 1067 Mhz 0.0%
C2 0.3ms ( 0.0%) 800 Mhz 100.0%
C3 1.9ms ( 0.1%)
C4 21.9ms (97.9%)