HP/Compaq nx6325 clock "jumping around"
nate at root.org
Sat Jul 5 17:26:26 UTC 2008
Bruce Evans wrote:
> On Fri, 4 Jul 2008, Nate Lawson wrote:
>>> On Wed, 2 Jul 2008, Joerg Wunsch wrote:
>> Bruce Evans wrote:
>>> I know of the following bugs in time on nx6325:
>> This reminds me -- the algorithm for estimating the cpu frequency
>> needs improvement. You had a patch you sent me that reduced its error
>> by a lot. Would you commit it?
> I'm further than ever from committing this, since I'm not set up for svn.
> I never merged this to the kernel. Running it in userland on more SMP
> machines shows the expected problems from the CPU not being pinnable in
I used it from the kernel and it worked fine but I was scared off by
some questions you had regarding the edge cases where calibration might
>>> dev.cpu.0.freq: 1985
>>> dev.cpu.0.freq_levels: 1985/-1 1736/-1 1488/-1 1240/-1 992/-1 744/-1
>>> 496/-1 248/-1
>>> Once I used some performance/power-reduction config and got a list
>>> like yours.
>>> 1985 actually gives 1995 MHz.
>> Your freq estimation patch does better than this.
> Aren't the above frequencies just read from acpi read-only data?
Depends on the back-end driver being used. dmesg | grep cpu will reveal
it. Some drivers like acpi_perf and est do have their own table.
Others like p4tcc and acpi_throttle have to estimate it.
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