On Thu, 2009-04-23 at 11:11 -0400, Ryan Lynch wrote:
As I understand it, a kernel ACPI facility called "PPC", related to how processors express their capabilities to the OS, is faulty, or the machine BIOS is faulty. Either way, this PPC facility is incorrectly warning the CPU Frequency scaling facility that the CPU is running too fast, which causes the scaling facility to slow down unnecessarily.
This requires a kernel or BIOS update to fix, but there is a decent workaround: Set the 'processor' module parameter called 'ignore_ppc' from the default '0' value to '1'. At runtime, you can set it via the R/W SysFS node '/sys/module/processor/parameters/ignore_ppc'. At boot time, use the option 'processor.ignore_ppc=1'--I added this to 'grub.conf'.
That sounds rather like ignore the problem rather than fix the problem (move the detection threshold, or correct the temperature monitor scaling so it provides accurate results).