Re: 3.9.0 + CONFIG_X86_INTEL_PSTATE=y -> ThinkPad T420 with i5 lostACPI functionality

From: Dirk Brandewie
Date: Mon May 13 2013 - 12:43:28 EST


On 05/03/2013 12:36 PM, Rafael J. Wysocki wrote:
On Friday, May 03, 2013 06:55:37 PM Toralf FÃrster wrote:
The following file doesn't exists at my Gentoo Linux
/sys/devices/system/cpu/cpufreq/ondemand/ignore_nice_load
in 3.9.0 if I activate CONFIG_X86_INTEL_PSTATE=y

That means, that a command like

$> echo 1 > /sys/devices/system/cpu/cpufreq/ondemand/ignore_nice_load

in /etc/rc.local is now no longer working.
A high fan + high temperature are the result, even if just the BOINC client
is run with low prio (nice 19) in the back ground.

Manually loading the missing module won't work too :

$> modprobe acpi_cpufreq
modprobe: ERROR: could not insert 'acpi_cpufreq': Device or resource busy

Is the behaviour a bug or a feature ?

The thermal management problem is not an intentional outcome, definitely.

In the later case: How can I achieve the previous behaviour back ?


I spent some more time looking for a solution to this you can get same behavior
by setting a config option in BOINC "Use at most X % CPU time"
see: http://boinc.berkeley.edu/wiki/Local_preferences


This issue might affect the RH EL kernel too [1] where I observed a similar behaviour.


[1] http://elrepo.org/bugs/view.php?id=379

Dirk, is this the problem we were talking about recently or something else?

Rafael



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