linux-kernel - cpufreq userspace governor doesn't work for Intel Core 2 Gen 2 CPUs

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Date:	Sun, 25 Dec 2011 18:36:29 +0000 (GMT)
From:	"Artem S. Tashkinov" <t.artem@...os.com>
To:	linux-kernel@...r.kernel.org
Cc:	davej@...hat.com, cpufreq@...r.kernel.org
Subject: cpufreq userspace governor doesn't work for Intel Core 2 Gen 2 CPUs

Hello,

On my Intel Core i5 CPU with acpi-cpufreq module loaded I do this

# echo 2000000 | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_setspeed

then

# cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq
2000000
2000000
2000000
2000000

so theoretically it should work.

However i7z (http://code.google.com/p/i7z/) shows that CPU frequency is freely floating
and turbo boost gets enabled as soon as I have any discernible load, in other words 
userspace CPU frequency driver doesn't work at all and it doesn't really enforce the specified
CPU frequency.

Best wishes,

Artem
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